阅读说明：本技术 用于在采矿机械中存储能量的系统、方法和设备 (System, method and apparatus for storing energy in mining machinery ) 是由 W·A·多塞特 J·B·迪林格 M·J·莱特恩 M·N·巴尔 B·M·尼尔森 D·F·奥因 于 2016-05-27 设计创作，主要内容包括：一种用于在采矿机械中存储能量的系统、方法和设备。一个实施例提供了一种运输车辆,所述运输车辆包括双向电气总线、耦接于所述双向电气总线的电源、耦接于所述双向电气总线并操作包括于所述运输车辆中的驱动机构的电动机、耦接于所述双向电气总线的动能存储系统以及被配置为与所述动能存储系统和所述电源通信的控制器。所述动能存储系统包括飞轮和开关磁阻电机。所述控制器被配置成操作所述动能存储系统作为所述双向电气总线的主电源,并且当所述动能存储系统不能满足所述双向电气总线上的能量需求时,操作所述电源作为所述双向电气总线的辅助电源。(A system, method and apparatus for storing energy in a mining machine. One embodiment provides a transport vehicle comprising a bidirectional electrical bus, a power source coupled to the bidirectional electrical bus, a motor coupled to the bidirectional electrical bus and operating a drive mechanism included in the transport vehicle, a kinetic energy storage system coupled to the bidirectional electrical bus, and a controller configured to communicate with the kinetic energy storage system and the power source. The kinetic energy storage system includes a flywheel and a switched reluctance motor. The controller is configured to operate the kinetic energy storage system as a primary power source for the bidirectional electrical bus and to operate the power source as a secondary power source for the bidirectional electrical bus when the kinetic energy storage system is unable to meet energy demands on the bidirectional electrical bus.)

1. A mining machine, characterized in that the mining machine comprises:

a bidirectional electrical bus;

a power source coupled to the bi-directional electrical bus;

an electric motor coupled to the bidirectional electrical bus, the electric motor being powered by energy available on the bidirectional electrical bus;

a kinetic energy storage system coupled to the bidirectional electrical bus; and

a controller configured to communicate with the kinetic energy storage system and the power source,

wherein the controller is configured to operate the kinetic energy storage system as a primary power source for the bidirectional electrical bus and to operate the power source as a secondary power source for the bidirectional electrical bus when the kinetic energy storage system is unable to meet energy demands on the bidirectional electrical bus.

2. The mining machine of claim 1, wherein the power source includes an engine and a switched reluctance motor/generator.

3. The mining machine of claim 2, wherein the switched reluctance motor/generator increases a speed of a drive train associated with the engine during braking of the drive mechanism.

4. The mining machine of claim 1, wherein the power source comprises a trailing cable.

5. The mining machine of claim 1, wherein the power source comprises a battery.

6. The mining machine of claim 1, wherein the power source comprises a fuel cell.

7. The mining machine of claim 1, wherein the electric motor comprises a second switched reluctance motor.

8. The mining machine of claim 1, wherein the controller is further configured to operate the kinetic energy storage system to store energy during braking of the drive mechanism.

9. The mining machine of claim 1, wherein the kinetic energy storage system comprises a switched reluctance motor.

10. The mining machine of claim 1, wherein the kinetic energy storage system comprises a flywheel, and the flywheel operates at a speed of from about 0 to about 6500 revolutions per minute.

11. The mining machine of claim 1, wherein the kinetic energy storage system outputs energy up to about 4000 horsepower per second.

12. The mining machine of claim 1, wherein the rotational speed of the flywheel decreases when the speed of the drive mechanism increases and increases when the speed of the drive mechanism decreases.

13. The mining machine of claim 1, further comprising a second kinetic energy storage system included in a common housing with the first kinetic energy storage system, wherein the second kinetic energy storage system includes a second flywheel.

14. The mining machine of claim 13, wherein the first flywheel of the first kinetic energy storage system rotates in a first direction and the second flywheel rotates in a second direction opposite the first direction.

15. The mining machine of claim 1, wherein the haulage vehicle further comprises a second kinetic energy storage system, a third kinetic energy storage system, and a fourth kinetic energy storage system, wherein the first kinetic energy storage system is arranged in a first primary direction along a plane, the second kinetic energy storage system is arranged in a second primary direction along the plane, the third kinetic energy storage system is arranged in a third primary direction along the plane, and the fourth kinetic energy storage system is arranged in a fourth primary direction along the plane.

16. The mining machine of claim 1, wherein the kinetic energy storage system is coupled to the bidirectional electrical bus by a power converter comprising a plurality of parallel power converters supplying energy from the bidirectional electrical bus to the kinetic energy storage system.

17. The mining machine of claim 1, wherein the kinetic energy storage system is coupled to the bidirectional electrical bus by a power converter comprising a plurality of parallel power converters supplying energy from the kinetic energy storage system to the bidirectional electrical bus.

18. The mining machine of claim 1, wherein the controller is in communication with the power source through an engine controller.

19. A method of operating a mining machine, characterized in that the method comprises:

determining, with a controller configured to communicate with a kinetic energy storage system and a power source included in the mining machine, an energy demand on a bi-directional electrical bus included in the mining machine;

determining, with the controller, energy available through the kinetic energy storage system;

operating the kinetic energy storage system with the controller as a primary power source for the bidirectional electrical bus when the energy available through the kinetic energy storage system satisfies the energy demand; and

operating the power supply with the controller as an auxiliary power supply to the bi-directional electrical bus when the energy available through the kinetic energy storage system fails to meet the energy demand.

20. The method of claim 19, wherein operating the kinetic energy storage system comprises controlling a rotational speed of a flywheel coupled to a switched reluctance motor.

Background

Embodiments of the present invention provide a mining machine that includes an energy storage device (such as a flywheel). In particular, certain embodiments of the present invention provide for the use of a flywheel energy storage system on a rubber-wheeled front-end articulating loader machine having a switched reluctance drive system.

Disclosure of Invention

Mining equipment is often operated in highly cyclical applications where direction changes and conventional start-stop activities are frequent. These cyclical operations may be used to excavate, load, move and handle minerals. For rubber wheel loaders or trucks, these cycles occur over a period of from about 30 seconds up to more than about 3 to 4 minutes, depending on the application. The difference in cycle periods for different applications may be caused by the haul length (the distance traveled by the machine between the point at which the machine collects material and the point at which the machine dumps material).

For example, for a surface front end loader loading truck in a surface mine, the haul length may be about 30 meters. Thus, if the front-end loader has a mechanical speed of less than about 15 kilometers per hour (kph), the front-end loader may complete a cycle in less than 30 seconds. However, for an underground loader operating in a block or plate cavern, its haul length may exceed about 300 meters. Thus, if the underground loader has a mechanical speed of about 20kph, the underground loader may complete one cycle in about 4 minutes.

Similarly, hauling equipment (such as shuttle cars) repeatedly accomplish the following tasks: the material is removed from the mining machine, hauled to account for material crushing or handling (such as a conveyor), and then returned to the mining machine to collect another load.

Large forklifts and draglines also operate in a cyclic manner. For example, forklifts and draglines dig and dump in a cyclic motion, where the direction of machine swing is reversed to return to a starting position while accelerating and decelerating large vehicle weights.

Thus, by using energy storage, there is an opportunity to increase the efficiency of the cyclical operation of the mining equipment. One opportunity includes capturing kinetic energy in the mechanical motion, storing the energy, and using the stored energy for the next motion phase of the cycle. Another opportunity includes making the peak power load of the battery more gradual by storing energy from the power supply at low loads and using the stored energy to assist the power supply in driving the peak load. This functionality may allow the size of the power supply (which may be a motor, transformer or trailing cable) to be reduced, reducing installation and maintenance costs. There is also an opportunity to improve the overall performance of the machine type for a given energy consumption with the same benefit gain.

Accordingly, embodiments of the present invention use an energy storage device comprising a flywheel or other form of Kinetic Energy Storage System (KESS). KESS may be used with Switched Reluctance (SR) technology to store energy in the form of kinetic energy for later use. Accordingly, embodiments of the present invention incorporate one or more KESS into high power mining traction applications that may be used for surface and underground machines incorporating SR technology.

In some embodiments, the KESS-integrated machines described herein may include a diesel engine as the primary power source. In this embodiment, the KESS uses braking energy and energy from the diesel output shaft to perform power averaging and boosting functions. However, it should be understood that the KESS may also be used with other (non-diesel) power sources. As described in detail below, the KESS may assist the engine during load peaks and extract energy from the engine during load dips. Thus, using a KESS of appropriate size, the KESS may be used to achieve full power averaging, where the engine is continuously running at a near constant load (e.g., without variation). Using the power averaging provided by KESS allows the engine to be miniaturized. Similarly, power averaging may extend engine life and maximize fuel savings by operating the engine at a constant output state.

Further, in some embodiments, the diesel engine may be replaced by a different power source (e.g., a battery). In particular, the full power averaging provided by a traction system with KESS (as developed with diesel engines) may optimize battery solutions for some machines, such as Scrapers (LHDs) and shuttles. It should be understood that other power sources, such as fuel cells, may also be used as an alternative to diesel engines (e.g., due to the power density of liquid fuel storage on a battery).

For example, some embodiments provide a tractor that includes a bidirectional electrical bus, a power source, a motor, a kinetic energy storage system, and a controller. A power source is coupled to the bidirectional electrical bus through a first power converter. The electric motor is coupled to the bidirectional electrical bus through a second power converter. The electric motor is powered by energy available on the bidirectional electrical bus and operates a drive mechanism included in the tractor. A kinetic energy storage system is coupled to the bi-directional electrical bus through a third power converter and includes a flywheel and a switched reluctance motor. A controller is configured to communicate with the kinetic energy storage system and the power source. A controller is configured to operate the kinetic energy storage system as a primary power source for the bidirectional electrical bus and to operate the power source as a secondary power source for the bidirectional electrical bus when the kinetic energy storage system is unable to meet energy demands on the bidirectional electrical bus.

Other embodiments provide a method of operating a tractor. The method includes determining, with a controller configured to communicate with a kinetic energy storage system and a power source included in the tractor, an energy demand on a bidirectional electrical bus included in the tractor, and determining, with the controller, energy available through the kinetic energy storage system. The method further includes operating the kinetic energy storage system with the controller as a primary power source for the bi-directional electrical bus when energy demand is met by energy available through the kinetic energy storage system; and operating the power supply with the controller as an auxiliary power supply for the bi-directional electrical bus when the energy available through the kinetic energy storage system fails to meet the energy demand.

Additional embodiments provide a transport vehicle including a dipper in at least one direction, an actuator for moving the dipper in at least one direction, an operator control including a selection mechanism, and a controller. The controller is configured to receive an input indicative of a selection of the selection mechanism. In response to the input, the controller is configured to determine a current position of the bucket, retrieve a predetermined load position from the memory, compare the current position of the bucket to the load position, and move the bucket to the predetermined load position when the current position of the bucket differs from the predetermined load position.

A further embodiment provides a method of automatically operating a transport vehicle. The method includes receiving, with a controller, an input indicative of a selection mechanism. The method also includes, in response to the received input, confirming, with the controller, a current position of the haulage vehicle bucket, and retrieving, with the controller, a predetermined load position from the memory. The method also includes comparing, with the controller, a current position of the bucket to a predetermined load position, and automatically controlling, with the controller, the actuator to move the bucket to the predetermined load position when the current position of the bucket differs from the predetermined device position.

Further embodiments provide a mining machine, comprising: a bidirectional electrical bus; a power source coupled to the bi-directional electrical bus; an electric motor coupled to the bidirectional electrical bus, the electric motor being powered by energy available on the bidirectional electrical bus; a kinetic energy storage system coupled to the bidirectional electrical bus; and a controller configured to communicate with the kinetic energy storage system and the power source. The controller is configured to operate the kinetic energy storage system as a primary power source for the bidirectional electrical bus and to operate the power source as a secondary power source for the bidirectional electrical bus when the kinetic energy storage system is unable to meet energy demands on the bidirectional electrical bus.

Further embodiments provide a method of operating a mining machine, the method comprising: determining, with a controller configured to communicate with a kinetic energy storage system and a power source included in the mining machine, an energy demand on a bi-directional electrical bus included in the mining machine; determining, with the controller, energy available through the kinetic energy storage system; operating the kinetic energy storage system with the controller as a primary power source for the bidirectional electrical bus when the energy available through the kinetic energy storage system satisfies the energy demand; and operating the power supply with the controller as an auxiliary power supply to the bi-directional electrical bus when the energy available through the kinetic energy storage system fails to meet the energy demand.

Other aspects of the invention will become apparent by consideration of the detailed description, accompanying drawings and the accompanying appendix.

Drawings

Fig. 1 shows the power curve of a mechanical drive system.

Fig. 2 shows a power curve of a Switched Reluctance (SR) drive system.

Fig. 3 schematically shows a system architecture for a diesel-hybrid SR surface loader.

FIG. 4 is a graph of SR mechanical efficiency.

Fig. 5 and 6 show power curves for an SR drive system with a Kinetic Energy Storage System (KESS).

Fig. 7 shows the power curve of an SR drive system with KESS and battery or fuel cell.

Fig. 8 schematically shows a system architecture of the SR driving system with KESS.

Fig. 9 shows a control curve of KESS.

Fig. 10 is a perspective view of a mining apparatus, in particular a front-end loader.

Figure 11 schematically illustrates functional elements of the mining apparatus shown in figure 10.

Fig. 12 schematically illustrates a controller included in the mining apparatus of fig. 10.

Fig. 13 schematically illustrates potential energy flow within the mining apparatus of fig. 10.

Fig. 14 schematically illustrates the energy flow within the apparatus of fig. 10 for charging a kinetic energy storage system.

Fig. 15 schematically illustrates the energy flow in the apparatus of fig. 10 for performing propulsion using a kinetic energy storage system.

Fig. 16 schematically shows the energy flow in the apparatus shown in fig. 10 for performing propulsion without using a kinetic energy storage system.

Fig. 17 schematically shows the energy flow for performing light braking in the device shown in fig. 10.

Fig. 18 schematically illustrates the energy flow in the apparatus of fig. 10 for performing strong braking and charging the kinetic energy storage system.

Fig. 19 schematically illustrates the energy flow in the apparatus shown in fig. 10 for performing strong braking without charging the kinetic energy storage system.

Fig. 20 schematically illustrates a mining machine including a plurality of kinetic energy storage systems.

Fig. 21 shows a scraper (LHD) with a bucket in a dumping position.

Figure 22 shows the LHD of figure 20 with the bucket in a digging position.

Figure 23 shows the LHD of figure 20 with the bucket in the loading position.

Detailed description of the invention

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

Further, it should be understood that embodiments of the invention may include hardware, software, and electronic components or modules, and that most of the components shown and described may be hardware only for purposes of discussion. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, aspects of the invention may be implemented by software (e.g., stored on a non-transitory computer-readable medium) executed by one or more processing units, such as a microprocessor, Application Specific Integrated Circuit (ASIC), or other electronic device. As such, it should be noted that the present invention may be implemented using a plurality of hardware and software based devices as well as a plurality of different structural components. For example, a "controller" described in this specification can include one or more electronic processors or processing units, one or more computer-readable media modules, one or more input/output interfaces, and various connections (e.g., a system bus) that connect the various components.

As described above, embodiments of the present invention incorporate one or more Kinetic Energy Storage Systems (KESS) into a mechanical traction drive train (e.g., high power) that may be used in mining machines that incorporate SR technology (e.g., open and underground mining machines). Thus, embodiments of the present invention may use KESS with an electric drive system. An electrically driven system may consume 30% to 40% less fuel than an equivalent system that is mechanically driven. These fuel savings can be achieved through differences and relative efficiencies of the various plant drivetrains. In particular, the mechanical drive systems currently used in open pit mining applications employ a conventional mechanical drive train having a torque converter, a semi-automatic or automatic transmission/transfer case, and a differential. However, due to the operation of the torque converter, the mechanical drive system may be inefficient and may require a large engine to provide high power output, even though the engine may not continue to operate at peak output levels. For example, fig. 1 shows a power curve of a mechanical drive system.

Switched reluctance electric drive systems have further efficiency advantages compared to mechanical drive trains. For example, the switched reluctance electric drive system may allow the engine to be reduced in size due to its ability to maintain engine speed at peak output levels. For example, fig. 2 shows a power curve of a switched reluctance drive system. Furthermore, fig. 3 schematically shows a surface loader with a diesel-hybrid SR drive. As described above, a surface loader basically operates or performs a cyclic operation. For example, an operating cycle of a surface loader may include approximately four changes in machine direction during a cycle that may last for approximately 40 seconds.

As shown particularly in FIG. 3, the surface loader includes an engine 10 and a traction system 13 in combination with a motor/generator 12 (e.g., an SR motor/generator). The traction system 13 shown in FIG. 1 includes four SR motors 14. Each SR motor 14 can supply power to one wheel of the loader. The SR motor 14 and the motor/generator 12 are connected by an electrical bus 16 (e.g., a Direct Current (DC) bus). One or more inverters 18 connect the motor/generator 12 to the electrical bus 16. Similarly, one or more inverters 18 connect the SR motor 14 to the electrical bus 16. The inverter 18 may convert the energy supplied by the motor/generator 12 into electrical power supplied through the electrical bus 16. Similarly, the inverter 18 may convert the energy supplied through the electrical bus 16 into energy usable by the SR motor 14.

In the system shown in FIG. 3, the Revolutions Per Minute (RPM) of the engine 10 is independent of the traction motor speed provided by the SR motor 14. In other words, each SR motor 14 may draw or provide rotational energy to the engine drive train at any speed with little consequence in terms of efficiency loss. In some embodiments, the speed of the engine 10 may be set to operate at the lowest RPM at which maximum engine horsepower is available.

The speed setting of engine 10 (at the peak of the power curve) facilitates increasing the speed of engine 10 above the governor set speed (engine overspeed), which causes the fuel injectors to stop fueling engine 10 and allows the driveline to be used as a flywheel to store braking energy. Mechanical drive systems are inefficient at transferring energy from the engine drive shaft to the wheels, particularly when the speed differential is large (e.g., due to operation of the torque converter in high differential speed conditions). Engines in mechanical transmission machines are typically at high load when the speed is below the peak horsepower curve; meaning that it burns fuel at less than maximum engine efficiency. Since mechanical drive systems typically require high power at non-optimal engine RPM, the engine may be relatively oversized, with the nameplate rating of the engine being similar, but requiring a larger engine volume. The larger engines result in mechanical designs that have higher operating and rebuild costs in addition to greater frictional losses.

Fig. 4 shows SR mechanical efficiency curves. The SR system can provide full torque to the wheels during stall, while consuming only about 10% of the engine horsepower. This may be due to the lower reactive losses of the SR system. For example, the only significant losses may be the internal resistance of the motor coil and the copper losses caused by the current passing through it. Thus, an SR machine (motor or generator) can have an almost flat efficiency curve over its speed range, as shown in fig. 4 above.

In contrast, mechanical transmissions are typically outputting at full horsepower during stall. The torque converter requires this power to produce torque. Most of this horsepower is lost as heat, which is a byproduct of the torque generation process. Further, torque converters are inefficient whenever there is significant slip or speed differential between the input and output shafts.

In fact, because the power output of the fixed shaft is zero, both systems are zero in efficiency during the standstill. In this case, the transmission efficiency may be measured as a function of output torque and power consumption. However, in this case, the SR drive system is more efficient in generating torque per unit power consumption than a typical mechanical transmission system.

Moreover, conventional brakes are used on mechanically driven machines. These brakes are typically multi-plate wet disc brakes. Like all mechanical brakes, these devices convert kinetic energy into thermal energy. The heat on the multi-disc brake is transferred to the hydraulic oil and dissipated through the radiator cooling system.

In SR drive machines, such as surface loaders, braking energy is transferred back to the engine drive train. In some embodiments, this braking energy is used as described below. In particular, braking energy may first supplement parasitic losses around the machine. These parasitic losses include, but are not limited to, engine fans and other cooling fans, air conditioning, and battery charging alternators. These systems are low power compared to the braking energy being transferred, and therefore there is also a large amount of energy to be handled.

The working hydraulic system load can then be supplied with energy. This includes crane, bucket and steering hydraulic functions. Any remaining energy may be used to power the drive train. For example, the SR generator, which is currently used as a motor, transfers power to the drive train to enable the engine's governor to reduce or shut off the fuel supply to the injectors. At this point, the engine may not consume any fuel, and the friction and windage losses of the engine are compensated for by the SR generator. In these embodiments, the engine speed may be increased to the mechanical limits of the engine, where the engine becomes an energy storage device (flywheel), although less efficient due to friction and windage of the engine. The overhead of engine speed above the governor cut-off point (e.g., about 300RPM) can be used in the next propulsion phase to increase the available power of the traction system above the nameplate rating of the engine. When the machine is cycling fast (e.g., less than 50 seconds), using the drive train as an energy storage device as described above provides an energy storage option, and this energy storage capacity is low because the energy stored on the drive train can be reused by the traction system before being consumed by frictional and windage losses of the engine. Thus, this energy storage option may be used for surface loaders in high altitude areas where overall oxygen available for engine combustion is low. For example, in high altitude areas, a turbocharger of larger diameter is typically required to supply air to the engine. Due to the large inertial mass, these turbochargers take a long time to reach operating speed. This time constraint can affect the response time of the engine. Thus, the KESS may supplement the power requirements of the traction system when the turbo boost reaches operating speed.

However, for underground mining, KESS may be used to store braking energy instead of, or in combination with, storing energy on the engine drive train. KESS improves fuel efficiency and thereby reduces emissions. In particular, KESS provides a longer duration, higher capacity and more efficient storage solution than the driveline storage solution used on the surface loader described in the preceding paragraph. For example, fig. 5 shows a power curve for a switched reluctance drive system including KESS. As shown in fig. 5, KESS may provide power boost to supplement the output of the engine, thus allowing the engine or a combination thereof to be miniaturized. For example, fig. 6 shows a power curve for a switched reluctance drive system that includes a KESS that is larger than the KESS shown in fig. 5. As shown in fig. 6, a larger KESS may provide maximum power averaging of the engine while providing high peak power for the traction system. Further, fig. 7 shows a power curve for a switched reluctance drive system that includes KESS as well as a battery (e.g., a sodium ion battery), a fuel cell, or both. As shown in fig. 7, for the averaging power supply, alternative power supply technologies such as fuel cell technology and battery technology may be employed.

The operating profile of an underground miner is significantly different from the operating profile of a surface miner (such as a loader, forklift, etc.). For example, open-air operating profiles are typically short, where the machine encounters four directional changes in a 40 second cycle and takes about 8 to 10 seconds to stall to fill the bucket. In contrast, there are two main modes of operation of the subsurface environment: (1) development and (2) production work. Both modes of operation differ from open air operation in terms of transport distance and integrated cycle time. For example, a subterranean machine may transport material distances of up to 200 meters in mine development and over 350 meters in production, which results in cycle times varying from about 2 minutes to about 3 minutes.

Also in underground mining environments, the production environment is typically flat. For example, the maximum slope seen in this operation is about 1: 50. As described above, underground machines may transport materials over distances of 350 meters or more. Moreover, in a production cycle, the machine will normally perform two forward transports and two reverse transports. Additionally, in many mines, the production loader may visit a number of extraction points at different distances from the crusher to collect ore. The nature of this cycle may therefore depend on the ore layout and the distance of the ore from the loading hopper of the crushing device.

Based on this type of environment, one opportunity to store energy during a production cycle is during a braking event. To maximize productivity, underground machines should be capable of rapid acceleration and deceleration. Thus, during deceleration, energy taken from the traction motors may be harvested for subsequent use by the KESS. Additionally, some of its available power may be used to power the KESS when the engine is in a low demand state. As described above, using stored energy in this manner may allow diesel engines to be downsized by averaging engine output power over a cycle. In addition to reducing engine size to reduce costs, in some embodiments, the amount of size reduction may also result in the use of a smaller case size engine, which provides additional performance gains due to further reduction in engine friction and windage losses.

The KESS used in these situations is capable of storing energy for one or two braking events (e.g., about 1.2 Megajoules (MJ) per event) at a high power capacity (e.g., about 500 Kilowatts (KW)) and allowing the KESS to fill or empty in a few seconds. The KESS may also be configured to provide efficient energy absorption and release and to maintain stored energy with minimal loss over time.

In terms of development environment, development work mostly occurs around mine entry roads or slopes. The slope of these slopes is typically around 1: 6.5. When operating in a development environment, underground machines excavate the bottom of a slope through drilling and blasting techniques, with roads extending therefrom. The machine then makes an inclined transport of between about 25 and about 200 meters, where the machine dumps or loads the material into a truck. The underground machine is then returned to the excavation face, which involves travelling down a slope of about 200 meters while controlling the speed by braking.

Uphill transport is engine power intensive and affects transmission life, while downhill return typically applies a large tension to the brakes. KESS (e.g., producing up to 10MJ) storing braking energy generated during downhill operation toward the excavation face may provide significant propulsion to the engine during uphill operation.

Fig. 8 shows an SR drive system with KESS 30. The KESS30 includes an SR drive motor 30a and a flywheel 30 b. In the configuration shown in FIG. 8, the KESS30 may be configured to store braking energy when the machine decelerates (reduction in speed of the drive mechanism) as commanded by the operator. The energy may be held in the KESS30 for several minutes. When the operator commands a mechanical acceleration, the KESS30 releases energy to the traction system to supplement the energy supplied by the engine (e.g., diesel engine) through the motor/generators. In some embodiments, this release of energy from the KESS30 allows the machine to have approximately twice the available peak horsepower as the engine output alone.

In the case where the engine is not operating at full load, there may be multiple periods during the operating cycle. During these periods, engine power may be used to "charge" the KESS 30. This function may ensure that the KESS30 is charged or fully charged prior to an acceleration event.

In some embodiments, the speed of the KESS30 may be loosely related to the mechanical speed. For example, as the machine accelerates (the speed of the drive mechanism increases), the KESS30 may slow (the rotational speed of the flywheel 122 may decrease) due to the function of releasing energy from the KESS 30. Conversely, when the machine decelerates (the speed of the drive mechanism decreases), the KESS30 may be charged and accelerate accordingly (the rotational speed of the flywheel 122 increases). One advantage of this operation of the KESS30 is that the gyroscopic forces of the KESS30 are minimal when the machine is at high speeds and moving rapidly or in contact with the wall may cause significant bearing or housing overload. In some embodiments, the target machine speed may be received from an operator control device.

For example, in some embodiments, the rotational speed of the KESS30 (the rotational speed of the flywheel 30 b) and, thus, the energy stored within the KESS30, is controlled as a function of the mechanical speed. For example, fig. 9 shows a control curve comparing the mechanical speed with the rotational speed of the KESS 30. Line 90 indicates the target speed of the KESS30 at a given mechanical speed, and the area 92 surrounding line 90 indicates the range of variation allowed around the target speed. The relationship shown in fig. 9 may be employed to provide for the management of the gyroscopic forces of the KESS30, which may be very high for KESS30 when high mechanical angular velocities (rates of change of direction) coincide with high speed rotation of the KESS 30. The shape of the curve also takes into account the energy required to accelerate and decelerate the machine and may be defined for a particular device and application.

As described in more detail below, in some embodiments, as the machine speed increases (during acceleration), energy is taken from the KESS30 and provided to the traction motors by applying the energy on a bidirectional bus (e.g., a DC bus) that powers the traction motors. This energy supply reduces the rotational speed of the KESS 30. When the traction system requires more power than the KESS30 provides, the diesel engine may provide supplemental energy. Similarly, when the KESS30 provides more energy than is required by the traction motors, the excess energy may be dissipated through the braking grids.

Also, as the machine speed decreases (during deceleration), the KESS30 is commanded to increase speed, taking the energy required to increase the KESS30 speed from the bidirectional bus. This energy is provided by the traction motor operating in a braking mode of operation. In some embodiments, energy may be received from the diesel engine via the generator when the KESS30 does not receive enough energy from the traction motors during braking mode operation to meet speed profile requirements. Similarly, when the KESS30 receives excess energy, the energy may be directed to the engine driveline through the generator to overcome any driveline losses and stop fueling to the engine. Any additional excess energy may be dissipated as heat through the braking grids.

Thus, as described above, KESS30 may provide or take energy from the bidirectional bus as determined by the control curve shown in fig. 9. The engine is only energized by the function of the generator when there is an insufficient energy provided by the KESS30 compared to the energy required by the traction motors. The difference between supply and demand is a function of the operating conditions to which the machine is subjected. For example, when the traction motors are operating in a propulsion mode and a braking mode, the slope or grade and rolling resistance of the road on which the machine is operating may change the supply-demand balance between KESS30 and the traction motors, which may change the amount of energy required or supplied. Thus, basically, the KESS30 may be the primary power source for the bidirectional bus and the engine may be the secondary power source for the bidirectional bus, such as when the KESS30 is unable to meet the power requirements on the bidirectional electrical bus.

Thus, in underground mining spaces, one benefit of the KESS30 is that the maximum engine horsepower of the machine operating in the environment may be reduced. This can be an important factor because engine horsepower can be a determining factor in underground mine ventilation requirements, which is a significant capital expenditure for the customer. For example, many jurisdictions use nameplate engine horsepower as the basis for ventilation airflow compliance.

For open air machines, KESS provides benefits at high altitudes where the engine response is diminished by leaner air (less overall oxygen available for engine combustion). For example, to overcome the air lean problem, engine manufacturers typically increase the diameter of the turbocharger. This increased diameter increases the inertia of the turbocharger, resulting in longer turbo lag (latency for turbocharger speed and boost). The KESS may be used to provide supplemental energy to the machine as engine horsepower output increases. For example, KESS may be used to smoothly load the engine to provide driveline response and therefore better operating performance, as well as to provide additional power boost from braking energy that would otherwise be dissipated as heat, or a combination thereof.

It should be understood that the size of the KESS (e.g., energy capacity and power rating) is based on the requirements of the actual application. For example, depending on the operating requirements of the machine, the KESS solution that some applications may use is a solution of low capacity and high power, or other combinations of capacity and power. For example, when the machine is providing maximum power for an extended period of time, the machine may be equipped with a KESS that provides high energy storage capacity and high power rating.

For example, fig. 10 shows a mining apparatus 100 according to an embodiment of the invention. The mining apparatus 100 may be an underground miner (e.g., a continuous miner, a haulage system, a longwall shearer, a loader, etc.) or a surface miner (e.g., a wheel loader, a hybrid shovel, a dragline miner, etc.). The mining apparatus 100 may include a chassis 101 and a traction system 102, such as a plurality of wheels rotatably coupled to the chassis 105. The mining apparatus 100 may also include other movable systems and components, such as a cable reel or swing system. In the embodiment shown in fig. 10, the mining apparatus 100 is a scraper conveyor (LHD) commonly used in underground mining environments.

As shown in fig. 11, the mining apparatus 100 includes a generator/engine 103. The generator/engine 103 may include a diesel engine that outputs mechanical energy and a generator that converts mechanical energy output by the engine into electrical energy. In some embodiments, the generator comprises an SR generator. In some embodiments, the generator may be used as a motor to increase engine speed (e.g., using the engine as an energy storage device used alone or in combination with the kinetic energy storage system described below). It should be understood that in some embodiments, the mining equipment 100 includes one or more generators powered by one or more engines.

The generator/engine 103 provides mechanical power (shown in phantom in fig. 11) to a hydraulic pump 104, which hydraulic pump 104 can use hydraulic energy (shown in phantom in fig. 11) to drive working cylinders and cooling fans and parasitic elements 107. Specifically, the rotational energy is provided to the hydraulic pump 104 through the generator and through the mechanical connection between the hydraulic pump 104 and the generator/engine 103. The generator/engine 103 also provides electrical power (shown in solid lines in fig. 11) to a bi-directional electrical bus 106, such as a capacitive Direct Current (DC) bus. The bi-directional electrical bus 106 supplies electrical power to one or more traction motors 108 (e.g., SR motors). For example, as shown in fig. 11, the mining apparatus 100 includes a left front traction motor 108A, a right front traction motor 108B, a left rear traction motor 108C, and a right rear traction motor 108D. Each traction motor 108 powers a wheel or other drive mechanism included in traction system 102. Specifically, each traction motor 108 converts electrical power received through the bi-directional electrical bus 106 into rotational energy for driving the drive mechanism. In some embodiments, the one or more traction motors 8 include SR motors.

In some embodiments, the bidirectional electrical bus 106 communicates with one or more converters 110. The converter 110 may be configured to transmit energy through the bidirectional electrical bus 106 or receive energy from the bidirectional electrical bus 106 (e.g., using the bidirectional electrical bus 106 as a bidirectional bus). Each converter 110 may be used as a DC to DC converter, a DC to AC inverter, an AC to DC rectifier, or other type of power converter. Alternatively or additionally, the inverter 110 may be used as a motor controller for the traction motor 108. For example, the inverter 110 may be configured to sense a characteristic of the traction motor 108 and respond to the sensed characteristic. In some embodiments, one or more of the converters 110 use insulated gate bipolar transistor ("IGBT") electrical switching devices. In some embodiments, multiple (e.g., parallel) converters may be used as components coupled to the bidirectional electrical bus 106. For example, the KESS120 may be connected with one or more parallel converters that control the flow of energy into or out of the KESS 120. Further, in some embodiments, the KESS120 may be connected with one or more parallel converters that control the flow of energy into the KESS120 and parallel converters that control the flow of energy out of the KESS 120. The use of multiple parallel converters may affect the performance of the KESS120 (e.g., faster charging, faster discharging, increased charging potential, increased discharging potential, or a combination thereof).

As shown in fig. 11, each traction motor 108 is associated with a braking grid 112. The braking grids 112 convert the kinetic energy of the traction motors into thermal energy (heat) during braking of the mining apparatus 100.

The mining equipment 100 also includes a kinetic energy storage system ("KESS") 120. The KESS120 may include a flywheel 122 and a motor/generator 124. In some embodiments, the motor/generator 124 comprises a variable speed motor, such as a variable speed SR motor/generator. For example, the act of storing and recovering energy from the KESS is related to accelerating and slowing the rotating mass. Thus, the wide constant speed and power range of SR motors is well suited for KESS. Flywheel 122 is mechanically coupled to motor/generator 124. The motor/generator 124 is configured to receive electrical energy from the bi-directional electrical bus 106 and output rotational energy to the flywheel 122, and optionally, to receive rotational energy from the flywheel 122 and output electrical energy to the bi-directional electrical bus 106. Accordingly, upon receiving electrical energy, motor/generator 124 rotates flywheel 122 to store kinetic energy. The stored energy may be harvested from the KESS120 by using the rotational energy from the flywheel 122 to rotate a rotor included in the motor/generator 124 that converts the rotational energy to electrical energy that may be supplied to the bi-directional electrical bus 106. In some embodiments, the flywheel 122 included in the KESS120 has a rotational speed of from about 0 to about 6500RPM, which allows the KESS120 to provide an energy output of up to about 4000 horsepower (hp) per second (about 3 MJ). In other embodiments, the flywheel 112 has a rotational speed of from about 3000RPM to about 10000RPM or from about 5000RPM to about 8000 RPM. Similarly, in some embodiments, the KESS120 provides an energy output from about 1MJ to about 15MJ or from about 2MJ to about 7 MJ. As described above, the energy output of the KESS120 may depend on the configuration of one or more converters coupling the KESS120 to the bidirectional electrical bus 106.

Although not shown in fig. 11, the mining equipment 100 also includes one or more controllers that manage the operation of the generator/engine 103 and the KESS 120. Specifically, the mining equipment 100 may include a controller that issues commands to the KESS120, including commands related to torque on the motor/generator 124, to store energy to the KESS120 or to harvest energy from the KESS 120. Similarly, the apparatus may include a controller that issues commands to the generator/engine 103 related to the output level of the engine, the generator, or both. Further, the mining equipment 100 may include a controller that issues commands to the traction motors 108 that drive the traction system 102. It should be understood that this function may be performed by a single controller or multiple controllers. Also, in some embodiments, this function or a portion of the function may be performed by one or more controllers remote from the mining apparatus 100, such as in a remote control station of the mining apparatus 100. In some embodiments, the functions performed by the controller described herein may be included in another component. For example, the controller may be included in the KESS120 (e.g., within a common housing).

As described above with respect to fig. 9, in some embodiments, the mining equipment 100 may include a controller that commands the KESS120 and the generator/engine 103 to supply or harvest energy based on the speed of the mining equipment 100. Specifically, as described in more detail below, the controller may issue commands to the KESS120 and the generator/motor 103 to place the KESS120 as the primary power source for the bidirectional electrical bus 106.

Fig. 12 shows one example of a controller 150 included in the mining apparatus 100. As shown in fig. 12, the controller 150 includes an electronic processor 152, such as one or more microprocessors, Application Specific Integrated Circuits (ASICs), or other electronic devices, a computer readable non-transitory memory 154, and an input/output interface 156. It should be understood that the controller 150 may include many more additional components than those shown in fig. 12, while the configuration of the components shown in fig. 12 is merely exemplary. The memory 154 stores instructions executable by the electronic processor 152 to issue commands as described above (e.g., via the input/output interface 156). For example, the controller 150 may issue commands to control the power flow described below in fig. 13-19. The controller 150 may also use the input/output interface 158 to receive information (e.g., operating parameters such as machine speed, steering direction, bus voltage, engine speed sensors, engine load, traction system load or command functions, hydraulic system load or command functions, etc.) that the controller 150 may use to determine when and what type of command to issue. For example, in some embodiments, the controller 150 controls the KESS120 based on one or more signals measured, received, or calculated for the mining equipment 100. It should be understood that the input/output interface 156 may be connected to elements external to the controller 150 (e.g., the KESS120, the generator/motor 103, the engine controller, etc.) via wired or wireless connections, including local area networks and controller area networks.

Fig. 13 shows the potential flow within the mining apparatus 100. Specifically, as shown in fig. 13, the hydraulic pump 104 consumes the energy provided by the generator/engine 103. However, the generator/engine 103 may also receive energy from the bi-directional electrical bus 106 (e.g., during a braking event). Further, each traction motor 108 may receive energy from the bidirectional electrical bus 106 and provide energy to the bidirectional electrical bus 106. Similarly, the KESS120 may receive energy from the bidirectional electrical bus 106 and provide energy to the bidirectional electrical bus 106. Instead, the braking grid 112 only consumes energy from the bi-directional electrical bus 106.

Fig. 14 shows the flow within the mining apparatus 100 for charging the KESS 120. Specifically, as illustrated in fig. 14, the power supplied by the generator/motor 103 is provided to the bi-directional electrical bus 106, the bi-directional electrical bus 106 supplying power for charging the KESS 120. In some embodiments, the KESS120 is charged during startup of the mining apparatus 100. However, in other embodiments, the KESS120 may be charged during low loads on the generator/engine 103.

Fig. 15 shows the flow in a mining apparatus 100 for performing propulsion using KESS 120. In particular, after the KESS120 is charged, the KESS120 may provide power to the bidirectional electrical bus 106. The electrical power is consumed by the traction motors 108. In some embodiments, the KESS120 acts as a primary or main power source for the traction motors 108. If the KESS120 is unable to adequately supply the required power to the traction motors 108, the traction motors 108 may receive power from the generator/generator 103, which generator/generator 103, as shown in FIG. 15, while providing power to the bi-directional electrical bus 106. Thus, in this configuration, the KESS120 is the primary energy provider of the traction system 102, while the generator/engine 103 provides a backup supply. The KESS120 is a more aggressive power source than the generator/engine 103. Thus, by first using a more aggressive power source, traction system 102 may be ramped up faster than conventional drive systems may allow. Further, using the KESS120 as a primary provider of energy may reduce the need for the generator/engine 103 to operate at full load. Specifically, as described above, using the KESS120 as the primary power source for the traction system 102 may allow the generator/engine 103 to operate at a more stable output, which saves fuel and reduces engine output requirements.

Thus, during operation of the mining equipment 100, the controller 150 may be configured to determine the energy demand on the bidirectional electrical bus 106 and determine the energy available through the KESS 120. When the energy demand is met by the energy available through the KESS120, the controller 150 may be configured to operate the KESS120 as a primary power source for the bidirectional electrical bus 106 (e.g., to control the rotational speed of the flywheel 122 included in the KESS 120). However, when the energy available through the KESS120 is unable to meet the energy demand, the controller 150 may operate the generator/motor 103 as an auxiliary power source to the bidirectional electrical bus 106 (i.e., while utilizing any available energy from the KESS 120) to meet the energy demand.

Fig. 16 shows the flow in a mining apparatus 100 that does not use KESS120 to perform propulsion. In this case, the traction motors 108 consume energy from the bidirectional electrical bus 106, the bidirectional electrical bus 106 being powered only by the generator/engine 103. This condition may be used when the KESS120 is not charging, malfunctioning, or not present.

Fig. 17 shows the flow in the mining apparatus 100 for performing light braking. As shown in fig. 17, when the traction system 102 is braking, the traction motors 108 act as generators and supply electrical energy to the bi-directional electrical bus 106. As in the case shown in fig. 17 (light braking), the energy supplied by the traction motor 108 may be supplied to a generator included in the generator/engine 103. The generator may use the received energy to accelerate the driveline between the generator/engine 103 and the hydraulic pump 104 (e.g., to accelerate the engine to a fixed speed point at which fuel injectors are commanded to stop delivering fuel to the engine). In some cases, the generator/engine 103 reduces fuel consumption (e.g., operates at zero fuel level) when the driveline is driven by a generator included in the generator/engine 103.

Similarly, fig. 18 shows the flow in the mining apparatus 100 performing heavy braking and charging the KESS 120. As shown in fig. 18, in these cases, the traction motors 108 act as generators and supply power to the bidirectional electrical bus 106. In the case shown in fig. 18 (heavy braking), the energy generated by the traction motor 108 and supplied to the bidirectional electrical bus 106 may be supplied to the generator and KESS120 included in the generator/engine 103.

Fig. 19 illustrates the flow of power in the mining equipment 100 performing a re-braking without charging the KESS120 (e.g., the KESS120 is fully charged, malfunctioning, or not present). As shown in fig. 19, in these cases, the traction motors 108 act as generators and supply power to the bidirectional electrical bus 106. Some of the supplied electric power is supplied to a generator included in the generator/engine 103. However, some of the supplied power will also be provided to one or more braking grids (braking grids) 112, which braking grids 112 convert the energy into heat.

It should be understood that other modes of operation may be used with the KESS 120. For example, in some embodiments, the generator/engine 103 may be used as a primary power source for the traction system 102, while the KESS120 may provide a backup power supply. In this configuration, the controller may be configured to issue commands to the KESS120 based on the operating speed of the traction system 102.

Also, in some embodiments, the mining equipment 100 provides a user interface that allows an operator to configure the KESS 120. In some embodiments, the user interface may also display (e.g., textually or graphically) the energy currently stored in the KESS 120.

It should also be understood that more than one KESS120 may be used for a particular mining machine depending on the energy requirements of the machine and the characteristics of the KESS 120. Also, in some embodiments, multiple KESS120 may be used to reduce gyroscopic effects associated with KESS (rotation of a flywheel). For example, two separate KESS120 (a first KESS120 and a second KESS 120) may be contained within a single housing such that the flywheel 122 counter-rotates to reduce the mechanical gyroscopic effect. For example, the first KESS120 may include a first flywheel 122 that rotates in a first direction, while the second KESS120 may include a second flywheel 122 that rotates in a second direction, opposite the first direction. Similarly, the four KESS120 (first KESS120, second KESS120, third KESS120, and fourth KESS 120) may be positioned in four primary directions along a plane to reduce gyroscopic effects. For example, as shown in fig. 20, a first KESS120 may be positioned in a first primary direction along a plane, a second KESS120 may be positioned in a second primary direction along a plane, a third KESS120 may be positioned in a third primary direction along a plane, and a fourth KESS120 may be positioned in a fourth primary direction along a plane.

As noted above, the mining equipment 100 may include a haulage vehicle, such as a LHD, which is commonly used in underground mining environments. As shown in fig. 20, LHD200 includes a bucket 202 supported by one or more arms 204, wherein bucket 202 is movable in at least one direction (e.g., horizontal height, an angle extending from horizontal position, or a combination thereof). The bucket 202 can be moved using one or more actuators included in the LHD200 (e.g., changing the position of the bucket 202, the arm 204, or both), such as one or more hydraulic actuators, rams (rams), or the like. The bucket 202 can be moved based on input received from operator controls included in the LHD200, such as a joystick, a lever, a button, a touch screen, and the like. A controller included in LHD200, such as controller 150 described above or a separate similar controller, may receive input and control (e.g., send commands to) one or more actuators in response thereto. In some embodiments, the controller is further configured to provide an automatic return to dig function.

For example, when the bucket 202 of the LHD200 is in a non-digging position (e.g., a dump position as shown in fig. 21), an operator operating the LHD200 can press a selection mechanism (e.g., a "return to dig" selection mechanism), such as a button located on an operator control included in the LHD200 (e.g., a right or left hand joystick of the LHD200, a touch screen, etc.) or located at a remote operator station of the LHD 200. When the operator selects the selection mechanism, the controller 150 receives a signal from the selection mechanism (e.g., directly or via one or more networks) and, in response, automatically controls one or more actuators associated with the dipper 202 to reposition the dipper 202 to a predetermined digging position (e.g., a predetermined height, a predetermined angle, or a combination thereof) (see fig. 22 for example). As shown in fig. 22, the return to the digging position may be defined as the bucket 202 being substantially level with the ground or excavated material.

For example, the controller 150 may retrieve a predetermined digging position from a memory (such as the memory 154 included in the controller 150) and compare the stored predetermined digging position to the current position of the dipper 202. As described below, the controller 150 may use data collected by one or more sensors to determine the current position of the dipper 202. When the positions are different, the controller 150 may control one or more actuators to change the current position of the dipper 202 to match the stored predetermined digging position. For example, when the current height of the dipper 202 is greater than the height in the predetermined dig location, the controller 150 may control one or more actuators to lower the dipper 202. Similarly, when the current angle of the dipper 202 is greater than the angle in the predetermined digging position, then the controller 150 may control one or more actuators to decrease the angle of the dipper 202.

In some embodiments, the controller 150 may repeatedly compare the current position of the dipper 202 to the stored predetermined digging positions while moving the dipper 202 until the positions align. Alternatively or additionally, the controller 150 may initially compare the current position of the dipper 202 with the stored predetermined digging positions and determine the amount of movement required to align the dipper 202 with the stored predetermined digging positions. The controller 150 may then command movement of the dipper 202 based on the determined distance. Accordingly, in either configuration, the controller 150 translates the difference between the current position and the stored position into one or a series of commands to one or more actuators, simulating commands received from an operator control. Thus, using the selection mechanism allows the operator to concentrate on driving the LHD200 without having to perform multiple joystick movements to return the bucket 202 to the dig position.

In some embodiments, the operator may manually adjust the predetermined digging position (e.g., a predetermined height, a predetermined angle, or a combination thereof) to suit the operator's preferences or operating environment. For example, an operator can signal (e.g., by selecting a selection mechanism or operating an operator control) when the bucket 202 is in a desired digging position. The controller 150 receives operator input and saves the current position (e.g., current height, current angle, or a combination thereof) of the bucket 202. The controller 150 may determine the current position based on data collected by one or more sensors (e.g., pressure sensors, encoders, inclinometers, etc.) in communication with the controller 150. The stored location information may be retrieved and applied when the operator subsequently selects the "return to dig" selection mechanism. In some embodiments, the modified predetermined dig location may be stored as an absolute location (e.g., height and angle). However, alternatively or additionally, the modified predetermined digging location may be stored as an offset (e.g., height offset and angle offset) from the default predetermined digging location. In some embodiments, the modified mining location may be reset to a default predetermined mining location after the LHD200 is shut down and restarted. In other embodiments, the modified mining location may be set to a default predetermined mining location (e.g., in response to selecting a "reset to default" selection mechanism).

Alternatively or additionally, the controller 150 included in the LHD200 may provide an automatic return shipping function. For example, when the bucket 202 of the LHD200 is in a non-digging position (e.g., a dump position as shown in fig. 21), an operator operating the LHD200 may press a selection mechanism (e.g., a "return to haul" selection mechanism), such as a button located on an operator control included in the LHD200 (e.g., a right or left hand joystick of the LHD200, a touch screen, etc.) or located at a remote operator station of the LHD 200. When the operator selects the selection mechanism, the controller 150 receives a signal from the selection mechanism (e.g., directly or through one or more networks) and, in response, automatically controls one or more actuators associated with the dipper to reposition the dipper 202 to a predetermined transport position (e.g., a predetermined height, a predetermined angle, or a combination thereof) (see fig. 23 for example).

For example, the controller 150 may retrieve the predetermined transport position from a memory (such as the memory 154 included in the controller 150) and compare the stored predetermined transport position to the current position of the bucket 202. As described above, the controller 150 may use data collected by one or more sensors to determine the current position of the dipper 202. When the positions are different, the controller 150 may control one or more actuators to change the current position of the bucket 202 to match the stored predetermined transport position. For example, when the current height of the dipper 202 is less than the height in the predetermined transport position, the controller 150 may control one or more actuators to raise the dipper 202. Similarly, when the current angle of the dipper 202 is less than the angle in the predetermined transport position, the controller 150 may control one or more actuators to increase the angle of the dipper 202.

In some embodiments, the controller 150 may repeatedly compare the current position of the dipper 202 to the stored predetermined transport position while moving the dipper 202 until the positions are aligned. Alternatively or additionally, the controller 150 may initially compare the current position of the bucket 202 to the stored predetermined transport position and determine the amount of movement required to align the bucket 202 with the stored predetermined transport position. The controller 150 may then command movement of the dipper 202 based on the determined distance. Accordingly, in either configuration, the controller 150 simulates commands received from an operator control, translating the difference between the current position and the stored position into one or a series of commands to one or more actuators. Thus, using a selection mechanism allows an operator to concentrate on driving the LHD200 without having to control multiple joystick movements to return the bucket 202 to the transport position.

In some embodiments, the operator may manually adjust the predetermined transport position (e.g., the predetermined height, the predetermined angle, or a combination thereof) to suit the operator's preferences or operating environment. For example, the operator may be able to signal (e.g., via a selection mechanism or operator control) when the bucket 202 is in a desired transport position. The controller 150 receives operator input and saves the current position (e.g., current height, current angle, or a combination thereof) of the bucket 202. The controller 150 may determine the current position based on data collected by one or more sensors (e.g., pressure sensors, encoders, inclinometers, etc.) in communication with the controller 150. The stored location information may be retrieved and applied when the operator subsequently selects the "return to transport" selection mechanism. In some embodiments, the modified predetermined transport position may be stored as an absolute position (e.g., height and angle). However, alternatively or additionally, the modified predetermined transport position may be stored as an offset (e.g., height offset and angle offset) of the default predetermined transport position. In some embodiments, the modified shipping location may be reset to a default predetermined shipping location after the LHD200 is shut down and restarted. In other embodiments, the modified transport position may be set to a default predetermined transport position (e.g., in response to selecting a "reset to default" selection mechanism).

As shown in fig. 23, the transport position may be defined as the bucket 202 being reeled up and the arm 204 being in a low position (the bucket 202 being in a low position and tucked in to place the bucket 202 in a very stable position so that the machine may be driven over long distances as it would normally be operated using the LHD). In particular, the transport position and subsequent automatic return transport function may provide benefits in situations where once the operator has filled the bucket 202 or dumped the bucket 202, the operator must drive the LHD200 over a significant distance (e.g., greater than about 500 feet). For example, open-air wheel loaders typically have a round trip of less than 300 feet between the haul truck and the excavation face. This distance is usually not necessary to place the bucket in the transport position. Rather, the surface loader arm can be used to fully raise the bucket or lower the bucket back to the digging position while traveling that distance. In contrast, the LHD return distance is typically 1000 feet or more. Accordingly, the automatic return to haul function provides benefits for a LHD that is driven remotely, where it is undesirable (e.g., for stability purposes) to drive the LHD with the bucket 202 fully raised.

Accordingly, embodiments of the present invention provide, among other things, a kinetic energy storage system for a mining machine. The kinetic energy storage system may utilize energy stored during engine start-up, during low engine loads, and during braking events to power a traction system of the mining machine.

Various features and advantages of the invention are set forth in the following claims.