阅读说明：本技术 一种发动机扭矩修正方法、系统和终端 (Engine torque correction method, system and terminal ) 是由 王希斐 万冬 王荫 李呈剑 庄焕强 卢成健 于 2020-12-29 设计创作，主要内容包括：本发明提供一种发动机扭矩修正方法,包括获取发动机当前点火角和发动机最佳点火角；根据发动机当前点火角和发动机最佳点火角,获取当前发动机点火角效率；获取车辆运行工况并获取点火角效率修正系数；获取周围环境信息并获取环境因素修正系数；获取燃料类型并获取燃料因素修正系数；根据点火角效率修正系数、环境因素修正系数和燃料因素修正系数,对当前发动机点火角效率进行修正得到修正后的发动机点火角效率；根据修正后的发动机点火角效率对发动机扭矩进行修正。本发明提供的发动机扭矩修正方法,通过引入车辆实时运行工况、车辆当前所处环境和车辆当前燃料类型,为发动机扭矩提供实时的、高精度的修正,且本发明提供的修正方法适用性更广。(The invention provides an engine torque correction method, which comprises the steps of obtaining the current ignition angle of an engine and the optimal ignition angle of the engine; obtaining the current engine ignition angle efficiency according to the current ignition angle of the engine and the optimal ignition angle of the engine; obtaining the running condition of the vehicle and obtaining an ignition angle efficiency correction coefficient; acquiring surrounding environment information and acquiring an environmental factor correction coefficient; acquiring a fuel type and acquiring a fuel factor correction coefficient; according to the ignition angle efficiency correction coefficient, the environmental factor correction coefficient and the fuel factor correction coefficient, correcting the current engine ignition angle efficiency to obtain the corrected engine ignition angle efficiency; and correcting the engine torque according to the corrected engine ignition angle efficiency. The engine torque correction method provided by the invention provides real-time and high-precision correction for the engine torque by introducing the real-time running working condition of the vehicle, the current environment of the vehicle and the current fuel type of the vehicle, and the correction method provided by the invention has wider applicability.)

1. An engine torque correction method characterized by comprising:

acquiring a current ignition angle and an optimal ignition angle of the engine;

obtaining the current engine ignition angle efficiency according to the current engine ignition angle and the optimal engine ignition angle;

obtaining a vehicle running condition, and obtaining an ignition angle efficiency correction coefficient according to the vehicle running condition;

acquiring ambient environment information, and acquiring an environmental factor correction coefficient according to the ambient environment information;

acquiring a fuel type, and acquiring a fuel factor correction coefficient according to the fuel type;

correcting the current engine ignition angle efficiency according to the ignition angle efficiency correction coefficient, the environmental factor correction coefficient and the fuel factor correction coefficient to obtain the corrected engine ignition angle efficiency;

and correcting the engine torque according to the corrected engine ignition angle efficiency.

2. An engine torque correction method as defined in claim 1, wherein said firing angle efficiency correction factor comprises a first correction factor and a second correction factor, said obtaining a vehicle operating condition and obtaining a firing angle efficiency correction factor based on said vehicle operating condition comprises:

the vehicle operating conditions comprise engine speed, intake load and intake manifold temperature;

acquiring a first correction coefficient according to the engine speed and the air inlet load;

and acquiring a second correction coefficient according to the engine speed and the temperature of the intake manifold.

3. An engine torque correction method according to claim 2,

the ignition angle efficiency correction coefficient is equal to a first correction coefficient × a second correction coefficient.

4. The engine torque correction method according to claim 3, wherein said acquiring the surrounding environment information includes:

acquiring ambient air pressure information;

and acquiring ambient temperature information.

5. The engine torque correction method according to claim 1,

the corrected engine ignition angle efficiency is equal to the current engine ignition angle efficiency × ignition angle efficiency correction coefficient × environmental factor correction coefficient × fuel factor correction coefficient.

6. An engine torque correction method as described in claim 1, wherein said correcting engine torque based on said corrected engine firing angle efficiency comprises:

acquiring the current basic torque of the engine;

obtaining the corrected engine ignition angle efficiency;

and correcting the current basic torque of the engine according to the corrected ignition angle efficiency of the engine to obtain the corrected torque of the engine.

7. The engine torque correction method according to claim 6,

the corrected engine torque is equal to the current engine base torque × the corrected engine firing angle efficiency.

8. An engine torque correction system, comprising:

the first acquisition module is used for acquiring the current ignition angle and the optimal ignition angle of the engine;

the second acquisition module is used for acquiring the current engine ignition angle efficiency according to the current engine ignition angle and the optimal engine ignition angle;

the third acquisition module is used for acquiring the running condition of the vehicle and acquiring an ignition angle efficiency correction coefficient according to the running condition of the vehicle;

the fourth acquisition module is used for acquiring the ambient environment information and acquiring an environmental factor correction coefficient according to the ambient environment information;

the fifth acquisition module is used for acquiring the fuel type and acquiring a fuel factor correction coefficient according to the fuel type;

the first correction module is used for correcting the current engine ignition angle efficiency according to the ignition angle efficiency correction coefficient, the environmental factor correction coefficient and the fuel factor correction coefficient to obtain the corrected engine ignition angle efficiency;

and the second correction module is used for correcting the engine torque according to the corrected engine ignition angle efficiency.

9. The engine torque correction system of claim 8, wherein the second correction module comprises:

the first acquisition unit is used for acquiring the current basic torque of the engine;

and the correction unit is used for correcting the current basic torque of the engine according to the corrected engine ignition angle efficiency to obtain the corrected engine torque.

10. A terminal comprising a processor and a memory;

the memory has stored therein at least one instruction or at least one program that is loaded and executed by the processor to implement the engine torque correction method of any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of engines, in particular to an engine torque correction method, an engine torque correction system and a terminal.

Background

In the control process of the traditional gasoline engine or dual-fuel engine, the accuracy requirement on an engine output torque model is high. In the prior art, engine torque model calibration is usually performed during bench calibration, which is usually performed based on boundary conditions of an ideal state, such as ambient temperature, water temperature, intake pressure, and the like; in practice, however, the whole vehicle needs to consider more complicated boundary conditions during use, for example, under extreme environmental conditions such as high altitude, high pressure, and low temperature, and therefore, the accuracy of the engine torque model may be deviated. In addition, extreme environmental conditions can also stack changes in boundary conditions such as air humidity, oil (single or dual fuel), etc., exacerbating the challenge to torque model accuracy. Especially for the situation that the external controller has torque interaction with the engine controller, such as for a car using an automatic transmission configuration, the clutch control has high precision requirement on an engine torque model due to an automatic transmission controller (TCU for short), and the TCU is very dependent on the engine torque model to accurately control the clutch action. Therefore, if the accuracy deviation of the torque model is large under certain working conditions, the drop or fluctuation of the rotating speed of the engine can be caused, the impact or the shaking of the whole vehicle can be caused, and the starting quality and the driving feeling of a user are negatively influenced.

It is conventional to optimize by two schemes: firstly, the accuracy of the torque model of the plain area and the extreme environment is balanced as much as possible, but the change of the external boundary condition cannot be considered, so that the accuracy of the torque of the plain area is reduced. Secondly, the disadvantage caused by insufficient torque precision is improved by sacrificing part of performance, for example, aiming at the problem of starting and jerking, the gearbox control unit can weaken the combination speed of a clutch or improve the air inflow of an engine; however, both of the two schemes have the defects that the reduction of the combination speed of the clutch can reduce the starting speed, and other problems of insufficient starting performance, insufficient dynamic performance and the like can be caused; increasing the engine intake air amount results in increased fuel consumption.

Aiming at the defects in the prior art, the invention aims to provide an engine torque correction method, an engine torque correction system and an engine torque correction terminal, which can better balance the accuracy of an engine torque model under ideal boundary conditions and extreme environment conditions and improve the adaptability and the accuracy of the torque model.

Disclosure of Invention

In view of the above problems of the prior art, an object of the present invention is to provide an engine torque correction method, including:

acquiring a current ignition angle and an optimal ignition angle of the engine;

obtaining the current engine ignition angle efficiency according to the current engine ignition angle and the optimal engine ignition angle;

obtaining a vehicle running condition, and obtaining an ignition angle efficiency correction coefficient according to the vehicle running condition;

acquiring ambient environment information, and acquiring an environmental factor correction coefficient according to the ambient environment information;

acquiring a fuel type, and acquiring a fuel factor correction coefficient according to the fuel type;

correcting the current engine ignition angle efficiency according to the ignition angle efficiency correction coefficient, the environmental factor correction coefficient and the fuel factor correction coefficient to obtain the corrected engine ignition angle efficiency;

and correcting the engine torque according to the corrected engine ignition angle efficiency.

Further, the acquiring the vehicle operating condition and acquiring the ignition angle efficiency correction coefficient according to the vehicle operating condition includes:

the vehicle operating conditions comprise engine speed, intake load and intake manifold temperature;

acquiring a first correction coefficient according to the engine speed and the air inlet load;

and acquiring a second correction coefficient according to the engine speed and the temperature of the intake manifold.

Specifically, the ignition angle efficiency correction coefficient is equal to a first correction coefficient × a second correction coefficient.

Specifically, the acquiring the ambient environment information includes:

acquiring ambient air pressure information;

and acquiring ambient temperature information.

Specifically, the corrected engine ignition angle efficiency is equal to the current engine ignition angle efficiency × ignition angle efficiency correction coefficient × environmental factor correction coefficient × fuel factor correction coefficient.

Further, the correcting the engine torque according to the corrected engine firing angle efficiency includes:

acquiring the current basic torque of the engine;

obtaining the corrected engine ignition angle efficiency;

and correcting the current basic torque of the engine according to the corrected ignition angle efficiency of the engine to obtain the corrected torque of the engine.

Specifically, the corrected engine torque is equal to the current engine base torque × the corrected engine firing angle efficiency.

Another aspect of the present invention provides an engine torque correction system, including:

the first acquisition module is used for acquiring the current ignition angle and the optimal ignition angle of the engine;

the second acquisition module is used for acquiring the current engine ignition angle efficiency according to the current engine ignition angle and the optimal engine ignition angle;

the third acquisition module is used for acquiring the running condition of the vehicle and acquiring an ignition angle efficiency correction coefficient according to the running condition of the vehicle;

the fourth acquisition module is used for acquiring the ambient environment information and acquiring an environmental factor correction coefficient according to the ambient environment information;

the fifth acquisition module is used for acquiring the fuel type and acquiring a fuel factor correction coefficient according to the fuel type;

the first correction module is used for correcting the current engine ignition angle efficiency according to the ignition angle efficiency correction coefficient, the environmental factor correction coefficient and the fuel factor correction coefficient to obtain the corrected engine ignition angle efficiency;

and the second correction module is used for correcting the engine torque according to the corrected engine ignition angle efficiency.

Preferably, the second modification module includes:

the first acquisition unit is used for acquiring the current basic torque of the engine;

and the correction unit is used for correcting the current basic torque of the engine according to the corrected engine ignition angle efficiency to obtain the corrected engine torque.

Another aspect of the invention protects a terminal comprising a processor and a memory;

the memory stores at least one instruction or at least one program, and the at least one instruction or the at least one program is loaded and executed by the processor to implement the engine torque correction method according to the above technical scheme.

Due to the technical scheme, the invention has the following beneficial effects:

1) according to the engine torque correction method provided by the invention, the current engine ignition angle efficiency is corrected by introducing the parameters such as the engine rotating speed, the air intake load and the like which characterize the operating condition of the engine, external environmental factors and fuel types, so that the ideal boundary condition during the calibration of the stand and the actual environmental condition during the running of a vehicle can be well balanced, and the real-time correction is provided for the engine torque.

2) The engine torque correction method provided by the invention can improve the accuracy of engine torque correction, so that the engine torque output is adaptive to the current running working condition, the dynamic requirement is met, and the fuel economy is improved.

3) The engine torque correction method provided by the invention can meet the requirements on engine torque correction under different environmental conditions and different working condition scenes, and is wide in applicability.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiment or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a flow chart of an engine torque correction method provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of an engine torque correction system according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a second modification module.

In the figure: 10-a first acquisition module, 20-a second acquisition module, 30-a third acquisition module, 40-a fourth acquisition module, 50-a fifth acquisition module, 60-a first correction module, 70-a second correction module, 71-a first acquisition unit, 72-a correction unit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions.

Examples

In the piston engine, the angle of rotation of the crankshaft during the period from the ignition time to the time when the piston reaches the top dead center of the compression stroke is the ignition angle. If the piston is ignited when reaching the compression top dead center, the fuel combustion force can not be fully exerted; however, if the ignition time is too early and the piston does not reach the compression top dead center, the fuel is already exerted with strength, and at the moment, the piston needs to be compressed continuously against the strength of fuel combustion, so that the pressure of the cylinder is suddenly increased, and the phenomenon is knocking (also commonly referred to as knock or knock); it is thus seen that neither too large nor too small an ignition angle is good.

In the prior art, the optimal ignition angle of an engine under various working conditions in an engine torque model is calibrated when a rack is calibrated. At the time of the optimal ignition angle calibration, environmental factors under ideal boundary conditions, such as ambient temperature, water temperature, intake pressure and the like, are generally considered by technicians, and the finally obtained optimal ignition angle is the ignition angle at which the engine obtains the optimal dynamic property, economical efficiency and optimal emission, and is an ideal ignition angle. In practice, the optimal ignition angle corresponding to each working condition cannot be achieved because the ideal boundary environment cannot be achieved when the vehicle runs under each working condition. In practice, therefore, the ignition angle is chosen at a point where the engine does not knock under most operating conditions, and is different from the ideal optimal ignition angle.

When the vehicle runs in a severe environment condition, for example, a plateau environment with thin air and small atmospheric pressure, the difference between the ignition angle actually adapted to the environment and the calibrated optimal ignition angle is larger, so that the output torque of the engine also has larger deviation from an ideal torque model when the rack is calibrated, the impact or the shaking of the whole vehicle is easily caused, and the starting quality and the driving feeling of a user are negatively influenced.

Therefore, with reference to fig. 1, the embodiments of the present disclosure aim to provide an engine torque correction method to solve the drawbacks of the prior art.

The method comprises the following steps:

s100: and acquiring the current ignition angle of the engine and the optimal ignition angle of the engine.

The optimal ignition angle of the engine can be directly determined under various working conditions (including an idling working condition, a small-load working condition, a medium-load working condition, a large-load/full-load working condition, an acceleration working condition and the like) determined during rack calibration in the development stage of the engine, and the current ignition angle of the engine can be obtained through a crankshaft position obtained by a crankshaft sensor.

S200: and acquiring the current engine ignition angle efficiency according to the current engine ignition angle and the optimal engine ignition angle, and recording the current engine ignition angle efficiency as eta 1.

In this specification, the current engine ignition angle efficiency η 1 ═ engine current ignition angle ÷ engine optimal ignition angle, that is, the current engine ignition angle efficiency is a parameter that can characterize the gap between the current ignition angle and the optimal ignition angle of the engine.

S300: and acquiring a vehicle running condition, and acquiring an ignition angle efficiency correction coefficient according to the vehicle running condition, wherein the ignition angle efficiency correction coefficient is recorded as A.

The vehicle running condition can be obtained through the engine speed, the air inlet load and the temperature of the air inlet manifold, and specifically, the engine running condition can be obtained through table lookup according to the engine speed and the air inlet load; the engine operating conditions are further identified with intake manifold temperature.

Taking an idle running condition as an example, the idle running condition refers to a no-load running state of an engine, at the moment, a clutch is in an engaging position, and a gearbox is in a neutral position (for an automatic gearbox vehicle, a parking gear or a P gear); when the obtained engine speed is in the range of 700r/min to 1100r/min and the throttle opening is in the range of 30 percent to 40 percent, the vehicle can be obtained by looking up a table when running in the idle working condition. The acquisition of other operating conditions of the vehicle operation is similar to the idle operating condition, and the details are not repeated here.

In some embodiments, the judgment of the vehicle running condition can be further accurately carried out by assisting the oxygen content in the cylinder, wherein the oxygen content in the cylinder is obtained by an oxygen content sensor; in addition, a knock sensor for measuring the engine shake can be provided.

The ignition angle efficiency correction coefficient includes a first correction coefficient and a second correction coefficient, and step S300 may specifically include the following sub-steps:

s310: the engine speed and the intake load are acquired.

The engine speed can be obtained through an engine speed sensor, and the air inlet load can be obtained through air inlet amount and/or air inlet pressure, fuel injection amount isobaric indirect representation.

S320: and acquiring a first correction coefficient according to the engine speed and the air intake load, wherein the first correction coefficient is A1. And respectively making a first map by taking the engine speed and the air intake load as an abscissa and an ordinate, and looking up a table according to the first map to obtain a first correction coefficient A1.

S330: an intake manifold temperature is acquired.

The intake manifold temperature may be obtained by a temperature sensor provided at the intake manifold.

S340: and acquiring a second correction coefficient according to the engine speed and the intake manifold temperature, wherein the second correction coefficient is A2. And (3) respectively making a second map by taking the engine speed and the temperature of the intake manifold as an abscissa and an ordinate, and looking up a table according to the second map to obtain a second correction coefficient A2.

S350: obtaining the ignition angle efficiency correction coefficient according to the first correction coefficient A1 and the second correction coefficient A2.

Specifically, in the embodiment of the present specification, the ignition angle efficiency correction coefficient is equal to a first correction coefficient × a second correction coefficient, that is, the ignition angle efficiency correction coefficient a is equal to a1 × a 2.

S400: and acquiring ambient environment information, and acquiring an environmental factor correction coefficient according to the ambient environment information, wherein the environmental factor correction coefficient is recorded as B.

Specifically, step S400 includes:

acquiring ambient air pressure information and ambient temperature information;

making a third map according to the ambient air pressure information and the ambient temperature information; and looking up a table according to a third map to obtain the environmental factor correction coefficient B.

In this embodiment, it may be determined in which external environment the current vehicle operates according to the ambient air pressure information and the ambient temperature information, for example: when the ambient air pressure is small, the vehicle can be judged to be in the plateau environment at the moment; when the ambient temperature is lower, the current vehicle can be judged to be running in a cold northern environment.

In some embodiments, the obtaining ambient information may further include: acquiring ambient environment humidity information; when the ambient environment humidity information indicates that the ambient environment humidity is high, it can be judged that the vehicle may be operated in a humid weather environment such as rain, fog and the like.

Accordingly, the environmental factor correction coefficient B may be obtained according to the ambient air pressure information, the ambient temperature information, and the ambient humidity information.

S500: acquiring a fuel type, and acquiring a fuel factor correction coefficient according to the fuel type, wherein the fuel factor correction coefficient is recorded as C. For example, a correction map is prepared according to the fuel type, and the fuel factor correction coefficient C is acquired from the correction map.

It should be noted that the engine torque correction system provided by the embodiment of the present specification is applicable to a dual-fuel engine, and includes two sets of fuel supply systems, one set is used for supplying methanol, and the other set is used for supplying gasoline; or one set is used for supplying natural gas, and the other set is used for supplying gasoline; the two sets of fuel supply the combustion chamber in a predetermined supply manner. The dual-fuel engine has the advantages of high calorific value of gasoline fuel and strong anti-detonation capability, can greatly reduce emission, and is increasingly favored by people.

For example, in the embodiment of the present specification, a gasoline fuel is used as a default flag, and when the current fuel type of the vehicle is a gasoline fuel, the fuel factor correction coefficient C at this time is set to 1; then when the fuel type is changed to methanol or natural gas, the fuel factor correction coefficient is set to not 1 to correct the ignition angle efficiency. Of course, other fuel types than gasoline fuel may be set as the default flag.

S600: and correcting the current engine ignition angle efficiency eta 1 according to the ignition angle efficiency correction coefficient A, the environmental factor correction coefficient B and the fuel factor correction coefficient C to obtain the corrected engine ignition angle efficiency.

If the corrected engine ignition angle efficiency is η 2, the corrected engine ignition angle efficiency η 2 is equal to the current engine ignition angle efficiency η 1 × the ignition angle efficiency correction coefficient a × the environmental factor correction coefficient B × the fuel factor correction coefficient C.

I.e. η 2 ═ η 1 × a × B × C

S700: and correcting the engine torque according to the corrected engine ignition angle efficiency eta 2.

Specifically, step S700 may further include:

s710: and acquiring the current basic torque of the engine. Note that the engine current base torque is M1.

S720: and acquiring the corrected engine ignition angle efficiency eta 2.

S730: and correcting the current basic torque of the engine according to the corrected engine ignition angle efficiency eta 2 to obtain the corrected engine torque.

If the corrected engine torque is M2, the corrected engine torque M2 is equal to the current engine base torque M1 × the corrected engine firing angle efficiency η 2.

That is, M2 is M1 × η 1 × A × B × C

According to the engine torque correction method provided by the embodiment of the specification, the current ignition angle efficiency of the engine is corrected in real time through the real-time operation working condition of the vehicle, the current environment of the vehicle and the current fuel type of the vehicle, and further the real-time correction of the engine torque is realized; the engine torque correction method provided by the embodiment of the specification can overcome the problem that the actual torque output deviation of the engine is large due to the fact that ideal boundary conditions are not in accordance with actual application scenes when the rack is calibrated, has higher correction precision on the engine torque aiming at the actual working scenes of the engine, and has the effects of improving the dynamic property and the fuel economy of the engine; the method for correcting the engine torque can meet the requirements of different environmental conditions and different working condition scenes, and has wider applicability.

As shown in fig. 2, an embodiment of the present disclosure further provides an engine torque correction system, which is configured to implement the engine torque correction method provided in the foregoing technical solution, and includes:

the first obtaining module 10 is used for obtaining the current ignition angle of the engine and the optimal ignition angle of the engine;

the second obtaining module 20 is configured to obtain a current engine ignition angle efficiency according to a current engine ignition angle and the optimal engine ignition angle;

the third obtaining module 30 is used for obtaining the vehicle running condition and obtaining the ignition angle efficiency correction coefficient according to the vehicle running condition;

a fourth obtaining module 40, configured to obtain ambient environment information, and obtain an environmental factor correction coefficient according to the ambient environment information;

a fifth obtaining module 50 for obtaining a fuel type and a fuel factor correction factor according to the fuel type;

the first correction module 60 is configured to correct the current engine ignition angle efficiency according to the ignition angle efficiency correction coefficient, the environmental factor correction coefficient, and the fuel factor correction coefficient, so as to obtain a corrected engine ignition angle efficiency;

a second correction module 70 is configured to correct the engine torque based on the corrected engine firing angle efficiency.

In some embodiments, the second modification module 70 specifically further includes:

a first acquisition unit 71 for acquiring a current base torque of the engine;

and the correcting unit 72 is configured to correct the current basic torque of the engine according to the corrected engine ignition angle efficiency, so as to obtain a corrected engine torque.

The embodiment of the specification also provides a terminal, which comprises a processor and a memory;

the memory stores at least one instruction or at least one program, and the at least one instruction or the at least one program is loaded and executed by the processor to realize the engine torque correction method provided by the technical scheme.

While the invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Also, in some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results.