阅读说明：本技术 用于定位移动组件的系统和方法 (System and method for locating a mobile assembly ) 是由 科恩·约瑟夫·梅森 于 2020-05-04 设计创作，主要内容包括：一种用于将移动组件(10)相对于静止组件(20)定位的系统和相关方法,该系统包括第一位置感测装置、控制器、附接至该移动组件的至少一个传感器。该第一位置感测装置(40)基于无线信号来感测第一数据,该第一数据表示该移动组件(10)与该静止组件(20)之间的相对位置。该控制器(31)基于该第一数据来确定第一轨迹(103)。该至少一个传感器(51,53)收集第二数据,该第二数据表示该移动组件执行的移位。该控制器(31)在该移动组件完成从该第一位置(101)沿着该第一轨迹(103)到第二位置(102)的移位之后,基于该第二数据来确定该第一轨迹(103)的校准偏移(105)。该控制器进一步在该移动组件完成从远离该静止组件的第三位置(101)沿着后续的第一轨迹(103)到靠近该静止组件的第四位置(102)的后续移位之后,迭代地改进该校准偏移。(A system and associated method for positioning a moving assembly (10) relative to a stationary assembly (20) includes a first position sensing device, a controller, at least one sensor attached to the moving assembly. The first position sensing device (40) senses first data based on wireless signals, the first data being indicative of a relative position between the moving component (10) and the stationary component (20). The controller (31) determines a first trajectory (103) based on the first data. The at least one sensor (51, 53) collects second data indicative of the displacement performed by the moving assembly. The controller (31) determines a calibration offset (105) for the first trajectory (103) based on the second data after the moving assembly completes a shift from the first position (101) to a second position (102) along the first trajectory (103). The controller further iteratively refines the calibration offset after the moving component completes a subsequent shift from a third position (101) away from the stationary component along a subsequent first trajectory (103) to a fourth position (102) proximate to the stationary component.)

1. A system (30) for positioning a moving assembly (10) relative to a stationary assembly (20), comprising:

a first position sensing device (40) configured to sense first data based on the wireless signal, the first data being indicative of a relative position between the moving component (10) and the stationary component (20);

a controller (31) configured to determine a first trajectory (103) from a first position (101) away from the stationary component to a second position (102) close to the stationary component based on the first data; and

at least one sensor (51, 53) attached to the moving assembly (10) and arranged for collecting second data representing a displacement performed by the moving assembly,

wherein the controller (31) is configured to determine a calibration offset (105) of the first trajectory (103) based on the second data after the moving component completes a shift from the first position (101) to the second position (102) along the first trajectory (103), and wherein the controller is configured to iteratively refine the calibration offset after the moving component completes a subsequent shift from a third position, remote from the stationary component, to a fourth position, close to the stationary component, along a subsequent first trajectory, preferably wherein the fourth position coincides with the second position.

2. The system of claim 1, wherein the controller is further configured to determine a compensated first trajectory based on the first trajectory and the calibration offset.

3. The system of claim 2, wherein the controller is configured to guide the moving assembly (10) from the first position (101) to the second position (102) based on the compensated first trajectory.

4. The system of any of claims 1 to 3, wherein the controller is configured to determine a second trajectory (104) based on the second data, the second trajectory representing a shift performed by the moving component, the controller being configured to determine the calibration offset (105) based on a difference between the first trajectory (103) and the second trajectory (104).

5. The system of claim 4, comprising means for recording a marker position of the moving component relative to the stationary component along the displacement, wherein the controller (31) is configured to determine the calibration offset by coinciding the first trajectory (103) and the second trajectory (104) at the mark position.

6. The system of claim 5, wherein the means for recording the marker position comprises a third sensor configured to collect third data indicative of the marker position, the third sensor being different from the position sensing device.

7. The system of claim 5 or 6, wherein the second location is the landmark location.

8. The system of any one of the preceding claims, wherein the first position sensing device (40) is configured to emit an electromagnetic or ultrasonic signal for sensing the first data.

9. The system of any one of the preceding claims, wherein the second position (102) is a parking position of the mobile assembly (10).

10. The system of claim 9, wherein the second position allows the transfer of common energy between the moving component and the stationary component (20).

11. The system of claim 10, wherein the transmission of the common energy source comprises transmission of electrical energy.

12. The system of any preceding claim, wherein the calibration offset comprises environmental distortion data, such as a map relating to the environment of the stationary component.

13. The system of any one of the preceding claims, wherein the controller (31) implements a machine learning algorithm or an iterative convergence algorithm to determine the calibration offset (105).

14. The system of any one of the preceding claims, wherein the at least one sensor (51, 53) is one or more of: an accelerometer, a gyroscope, a rotation angle sensor, a rotation speed sensor, and a steering angle sensor.

15. The system of any one of the preceding claims, wherein the system is configured to collect fourth data representing an orientation of the moving component relative to the stationary component, wherein the controller is configured to determine the orientation at least one position along the displacement and to determine the calibration offset based on the orientation.

16. The system of any one of the preceding claims, wherein sensing first data based on the wireless signal comprises measuring a parameter of the wireless signal representative of the relative position.

17. A controller as described in any one of the preceding claims.

18. A stationary assembly (20) comprising the controller of claim 17.

19. A method (200) for positioning a moving assembly (10) relative to a stationary assembly (20), comprising the steps of:

determining a first trajectory (103) for positioning the moving component (10) from a first position (101) away from the stationary component (20) to a second position (102) close to the stationary component by sensing a relative position between the moving component and the stationary component based on a wireless signal,

performing a displacement of the moving component from the first position (101) to the second position (102) based on the first trajectory (103),

determining a calibration offset (105) of the first trajectory (103) based on sensor data collected on the moving assembly (10) during the performing of the displacement, the sensor data not being the wireless signal,

iteratively refining the calibration offset after the moving component has completed performing a subsequent shift from a third position away from the stationary component along a subsequent first trajectory to a fourth position proximate to the stationary component, preferably wherein the fourth position and the second position coincide.

20. The method of claim 19, wherein a compensated first trajectory is determined based on a subsequent first trajectory from the third location to the fourth location and the calibration offset, and wherein a subsequent shift from the third location to the fourth location is performed based on the compensated first trajectory.

21. The method of claim 19 or 20, wherein each shift is performed by directing the moving assembly.

22. The method of any of claims 19 to 21, comprising determining a second trajectory (104) based on the sensor data, the second trajectory representing a shift performed by the moving component, wherein determining the calibration offset comprises evaluating a difference between the first trajectory (103) and the second trajectory (104).

23. The method of claim 22, comprising recording a marker position of the moving component relative to the stationary component along the displacement, wherein determining the calibration offset (105) comprises coinciding the second trajectory with the first trajectory (103) at the marker position.

24. The method of claim 23, comprising collecting third data different from the wireless signal and using the third data to record the marker position.

25. The method of claim 23 or 24, wherein the landmark location is the second location.

26. The method of any one of claims 19 to 25, wherein the second position (102) is a parking position of the mobile assembly.

27. The method of claim 26, wherein the parked position allows a common energy source to be transferred between the moving component and the stationary component.

28. The method of claim 27, wherein transmitting a common source of energy comprises transmitting electrical energy.

29. The method of any one of claims 19 to 28, comprising: fourth data representing an orientation of the moving component relative to the stationary component is collected, and the calibration offset is determined based on the fourth data.

30. The method of claim 29 in combination with any of claims 22-25, comprising determining the second trajectory based on the fourth data.

31. The method of any of claims 19 to 30, wherein the calibration offset comprises environmental distortion data, such as a map relating to the environment of the stationary component.

32. The method of any of claims 19 to 31, wherein the calibration offset (105) is determined by a machine learning algorithm or an iterative convergence algorithm.

33. The method of any one of claims 19-32, wherein sensing the relative position includes measuring a parameter of the wireless signal.

34. A program code which, when implemented on a computer, is configured to perform the method of any of claims 19 to 33.

35. A control unit for implementing the method of any one of claims 19 to 33.

Technical Field

The present invention relates to a system and method for positioning a stationary component and a moving component relative to each other. Possible applications are the positioning of electric vehicles, automatic guided vehicles (vehicles), autonomous vehicles, or unmanned aerial vehicles. The system and method of the present invention are particularly useful in locating vehicles for conductive and/or wireless power transfer.

Background

In order to automatically charge a vehicle (referred to as a mobile component), the vehicle must be parked at a location within a predefined charging range of a conductive or wireless charging device (referred to as a stationary component). This charging range is typically less than 500x 500 mm. To assist the driver or autonomous vehicle in reaching this location, the charging system typically includes a positioning system ranging up to several meters (i.e., 0.5m-10m) that estimates the location of the charging area relative to the vehicle (or vice versa).

Positioning systems typically include a transmitter and a receiver integrated into the moving assembly, the stationary assembly, or both. Based on the transmitted and received signals, relative and/or absolute positions with respect to each other may be determined.

In general, the environment surrounding the stationary components may distort the signals used by the positioning system. For example, when using a magnetic field-based positioning system, nearby magnetically permeable or electrically conductive materials may dampen or reflect the magnetic field. In the case of ultrasound-based systems, sound reflections from nearby objects may distort the received signal. Thus, the position signal provided by the positioning system calibrated in the laboratory environment deviates from the actual position in the installation environment.

With regard to commonly used positioning systems, other trajectory information, such as wheel rotations, autopilot cameras, etc., is also typically present on the moving assembly.

It is known from WO 2014/183926 of 11/20/2014 to align a vehicle with a stationary power transmission unit by providing this additional trajectory information collected by the vehicle's own sensors (such as rotational speed sensors, accelerometers, gyroscopes, etc.) as redundant information for the parking aid control unit when performing a trajectory of the vehicle towards the stationary unit. The parking assist control unit may then correct its trajectory based on this redundant information. While this method allows for higher positioning accuracy for the immediate trajectory, it does not improve the calculation of subsequent trajectories in subsequent parking maneuvers.

Disclosure of Invention

The present invention is directed to addressing at least one and preferably all of the disadvantages of systems known in the art. This can be achieved by combining such additional trajectory information from the moving component to improve (a posteriori) the estimate of the position of the moving component relative to the stationary component each time a positioning sequence is performed.

Accordingly, the present invention is directed to providing a more accurate and/or efficient positioning system and method in determining positioning information to direct a moving component toward a stationary component.

According to the present invention, distortion of the position information caused by the environment is not eliminated. Instead, the (fixed) environmental distortion is taken into account by compensating the calculated position over time (i.e. iteratively). This can be done by using learning techniques such as machine learning.

Distortion compensation is improved by combining a calculated trajectory from a positioning system (referred to as a first positioning system) with measurement data from one or more second sensors on a moving assembly different from the first positioning system. Advantageously, the first positioning system does not use the one or more second sensors when calculating the trajectory. The one or more second sensors are advantageously complementary to the sensors of the positioning system and are used to form a second positioning system for calibrating and/or adapting the trajectory determined by the first positioning system. Advantageously, a second trajectory of the moving component relative to the stationary component is determined from the data of the one or more second sensors. The combination of the measured signals of the two positioning systems is used to improve the position estimate for the first positioning system with the aim of learning and/or calibrating the environment of the first positioning system. As an additional advantage, after some iterations, absolute position data can be obtained from the measurements of the first positioning system when an adjustment of the calibration offset obtained by a plurality of second trajectories determined by a so-called second positioning system is made.

Thus, according to a first aspect of the present invention, there is provided a system for positioning a moving component relative to a stationary component as set out in the appended claims.

A system for positioning a moving component relative to a stationary component according to the present invention includes a first position sensing device, a controller, and at least one sensor attached to the moving component. The first position sensing device is configured to sense first data indicative of a relative position between the moving component and the stationary component based on a wireless signal, which may be an electromagnetic signal (e.g., radio waves, magnetic fields, or optical signals), an ultrasonic or acoustic signal, or any other suitable signal. The controller may be configured to determine a relative position or first trajectory from a first position away from the stationary component to a second position proximate to the stationary component based on such first data. The at least one sensor is arranged to collect second data indicative of the displacement performed by the moving component. The controller is further configured to determine a calibration offset for the first trajectory based on the second data. Such calibration offsets may include environmental distortion data (e.g., maps) such as (relative) positional offset data configured to improve the first trajectory. The calibration offset is determined after the moving component completes a displacement from a first position (101) away from the stationary component along a first trajectory (103) to a second position (102) close to the stationary component. The controller may be further configured to iteratively refine the calibration offset after the moving assembly completes a subsequent shift from the third position to a fourth position, the fourth position preferably coinciding with the second position. Optionally, the controller is further configured to compensate the first trajectory based on the calibration offset.

Embodiments of such a system may further be configured to guide the displacement of the moving component from the first position to the second position, e.g. based on the compensated first trajectory. For such embodiments, the controller may be configured to determine the first trajectory to guide the moving assembly from the first position to the second position. In such embodiments, the first trajectory or the compensated first trajectory is determined before performing the displacement of the moving component towards the stationary component. The controller typically requires information about the estimated relative position between the moving and stationary components and thus determines a compensated first trajectory based on the first data and the calibration offset. The controller may be further configured to determine the first trajectory based on additional data, such as an orientation of the moving component relative to the stationary component and/or a minimum turn radius of the moving component. Such embodiments of the system may also facilitate autonomously moving the moving component along the first trajectory.

In an alternative embodiment, the controller may be configured to guide the moving assembly from the first position to the second position based on the relative position, which may be determined based on the first data and, for example, a calibration offset (e.g., the compensated first trajectory). The controller may be further configured to determine a first trajectory based on the first data. In such embodiments, the moving assembly is guided using only the relative position, for example by having an operator operating the moving assembly see the relative position of the stationary assembly on a display. Next, for example, the operator displaces the moving assembly toward the stationary assembly. Subsequently, the controller determines the first trajectory, for example by recording the first data during or after the shifting.

Such wireless signal first data may, for example, comprise parameters of the wireless signal, such as a delay in receiving the wireless signal (e.g., time of arrival of the wireless signal, time difference in arrival of the wireless signal, e.g., transmitted from or arriving at the plurality of sensors), signal strength, signal amplitude, signal phase, or a combination of these. The controller may be configured to determine the relative position based on such first data using one or more methods (e.g., multilateration, triangulation). Some types of wireless signals may be affected by environmental factors (e.g., temperature, pressure). Thus, the system may include additional sensors to determine these environmental factors, which provide additional data to the controller to improve the determination of the relative position based on the first data.

Different methods may be used to determine the relative position based on the wireless signals. Typically, the controller uses the calculated position of the source or sources relative to the sensor or sensors to determine the relative position. In the case of ultrasound-based signals, the system may be implemented by providing a moving assembly and a stationary assembly including one or more ultrasound transducers, where one of the assemblies may include a transducer (e.g., a transmitter) that transmits ultrasound signals, and another of the assemblies may include a transducer (e.g., a sensor) for receiving ultrasound signals. Such wireless signals have a known (or substantially known) speed of propagation in air. The controller may be configured to determine when the ultrasound signal arrives at the one or more sensors and apply multilateration to calculate the position of the emitter(s) relative to the sensor(s). Alternatively, to eliminate the need for synchronization between the emitter and sensor, the controller may be configured to determine the time difference of arrival for each sensor pair and apply multilateration to calculate the position of the emitter(s) relative to the sensor(s). Either way, the first position sensing device may include additional sensors, such as temperature sensors or pressure sensors, which may provide such information about the environment to the controller to enable improved determination of the relative position, as the speed of sound may be determined more accurately. In case the beam patterns of the sensor and the emitter coincide, the relative signal strength may also be used as the first data.

In embodiments where the wireless signals comprise radio waves, the relative position may be determined using a similar method or controller as the ultrasound signals. For example, for ultra-wideband, the first data may typically comprise time of arrival or time difference of arrival as the first data, and the controller may be configured to determine the relative position based on multipoint positioning. Alternatively, for Wifi or bluetooth wireless signals, the first data typically includes signal strength, and the controller may be configured to determine the relative position using the first data based on the multilateration.

Embodiments in which the wireless signal comprises a magnetic field typically use low frequency magnetic field (up to 150kHz) signals. The moving or stationary assembly may be configured as a transmitter with one or more coils oriented orthogonally to each other. Another component may include a sensor for sensing a magnetic field. Typically, different sensors may be used for different axes (x, y, z). These sensors may include simple coils (e.g., configured to measure induced voltage), hall effect sensors, or magnetoresistive sensors for measuring magnetic fields. The relative position may be determined in a number of ways. For example, the first data may include relative signal strengths, and the controller may be configured to determine the first data based on a multilateration or a diamagnetic model using the first data. The controller may be based on a Biot Savart theoretical model that shows the magnetic field originating from the current carrying wire as a function of position in 3D space. By reversing this model, the measured magnetic field is the input, and the position in 3D space is the output. The first data may also include a phase of the wireless signal, and the controller may be configured to use this additional first data in the same diamagnetic model. Alternatively, the first data comprises a phase of the wireless signal, and the controller may be configured to determine the relative position using the first data based on triangulation.

The at least one second sensor is arranged for collecting second data representative of the displacement performed by the moving assembly and may be any sensor useful for this purpose. For example, the at least one sensor is one or more of: accelerometers, gyroscopes, rotational angle encoders, rotational speed sensors, and steering angle sensors, i.e., sensors typically found on moving components such as vehicles and the like. Advantageously, the at least one second sensor does not form part of the position sensing device, and advantageously the data obtained therefrom (second data) is not used for determining the first trajectory. Thus, the second data is different from the first data.

According to the invention, the controller is further configured to determine a calibration offset for the first trajectory based on the second data. The controller is configured to determine a calibration offset for the entire first trajectory between the first position and the second position. Advantageously, the calibration offset is determined after the displacement is completed when the moving assembly performs the first trajectory from the first position to the second position, for example when the moving assembly has reached or reached the stationary assembly and/or is in the second position. By determining the calibration offset only when the mobile assembly reaches the final destination, the entire trajectory between the first and second positions may be considered in compensating for the distortion of the first trajectory. This is not possible when calibrating the trajectory piecewise, for example between every two consecutive intermediate positions along the first trajectory. Thus, an improved distortion compensation is obtained, which may provide a faster convergence.

The calibration offset comprises environmental distortion data forming a map, such as (relative) positional offset data. This illustration includes, for example, information about distortion of the first data at various locations within the environmental region. Such a calibration offset is derived from the difference between the first trajectory and the second trajectory. After a plurality of shifts from the first position to the second position, the calibration offset includes information about various routes (e.g., distance, orientation) of the moving component toward the stationary component. Thus, for example, if the translation data and rotation data of the moving assembly are stored as a function of the first trajectory, the map is preferably iteratively updated for each route and may be implemented as a multi-dimensional look-up table. In subsequent routes, the distorted data of this map is used to adjust/refine the first trajectory, e.g., based on an improved position estimate from the first data. In the case where the first trajectory is new, i.e. no distortion data is present in the map of the estimated position, interpolation of the calibration data may be used to obtain derived distortion data for the estimated position. Subsequent shifts may improve the calibration offset by increasing the number of estimated positions for which distortion data is collected or by updating distortion data for estimated positions already present in the map.

Advantageously, the controller is configured to determine a second trajectory representing the displacement performed by the moving assembly, i.e. from the first position to the second position. Advantageously, the second trajectory is determined without using the first data. Advantageously, the second trajectory is determined based only on the second data. The controller is further configured to determine a calibration offset based on a difference between the first trajectory and the second trajectory.

To determine the calibration offset, it is advantageous that the controller is configured to let the first and second trajectories coincide at a marker position, which may be, but need not be, the second position. Advantageously, the marker position is a position determined by a third sensor configured to collect third data representative of the marker position. Advantageously, the third sensor is different from the first position sensor. Thus, the index position is a position included in both the first track and the second track. Advantageously, the second trajectory is constituted by using the marker position as a common point or coincident point with the first trajectory. Next, for example, when the marker position and the second position are adjacent positions, a second trajectory from the marker position or the second position back to the first position may be calculated, for example, by coordinate transformation. This allows to permissibly reconstruct the second trajectory and to obtain an accurate relationship between the first trajectory and the second trajectory for determining the calibration offset. Advantageously, the index position is a point shared between the first trajectory and the second trajectory, for example because in any case the mobile assembly has to pass the index position to reach the second position. Alternatively or additionally, the first data, the second data, or both, include timestamp information related to executing the first trace or the second trace, respectively. The time stamp information allows the two tracks to be associated when the positions are marked. The time stamp between the moving component (second sensor) and the position sensing device may be synchronized at the first location, the second location, the marker location, and/or any other suitable location.

Advantageously, the controller is configured to determine the second trajectory after the moving assembly has been guided/positioned to/at the landmark position or the second position. Advantageously, the second position is a (final) parking position of the moving component, such as a position aligned with the stationary component. Such a parking position is a position that allows the transmission of a common energy source between the mobile and stationary components. By doing so, the two trajectories share a common position, thereby easily determining the calibration offset.

Advantageously, the first position is a starting position for guiding the moving component to the stationary component (e.g. the second position). The first position may refer to a position of the respective moving component that is first sensed by the first position sensor. Advantageously, the first or starting position corresponds to the furthest position of the mobile component sensed by the wireless signal of the position sensing device, or to the following positions: the wireless signal determines the position of the mobile component for the first time after communication between the mobile component and the stationary component is initiated. The location may be the location of the first contact between the moving and stationary components, for example, in the case of an initialization of a wireless communication between the moving and stationary components. Advantageously, the first position corresponds to the following position: the position of the guidance path, i.e. the first trajectory, is determined for the first time.

Advantageously, the controller is configured to collect fourth data indicative of the orientation of the moving component relative to the stationary component. The controller is configured to determine an orientation along at least one position of the displacement, such as the first position, the second position, the marker position, or any other suitable position. The controller may, for example, be configured to determine the second trajectory based on the fourth data. Accordingly, the controller may be configured to determine the calibration offset based on (e.g., taking into account) the orientation. This improves the accuracy of determining the second trajectory and may result in faster convergence. The fourth data may be collected by a fourth sensor different from the first sensor, the second sensor, and the third sensor. Alternatively, the fourth data may be collected using any one or combination of the first sensor, the second sensor, or the third sensor.

Advantageously, the controller implements a machine learning algorithm or an iterative convergence algorithm. Advantageously, such an algorithm is used to determine or adjust the calibration offset in an adaptive manner, for example based on sets of first and second trajectories that have been collected. This ensures that the adapted first trajectory (adapted by the calibration offset) converges smoothly towards the actual trajectory and/or towards the exact relative or absolute position.

Advantageously, the controller is configured to adapt the first trajectory by calibrating the offset. The controller may be configured to determine a distortion compensation for the position estimate of the position sensing device based on the calibration offset. The controller may use distortion compensation when determining subsequent trajectories.

Advantageously, the controller is implemented in a stationary assembly. Advantageously, one or both of the controller portion implemented to determine the first trajectory and the controller portion implemented to determine the second trajectory are located in the stationary component.

The stationary component may refer to a grounded component for wireless power transmission or a docking station (docking station) for wired power transmission. A mobile assembly may refer to any vehicle (e.g., a battery-powered vehicle, an automated guided vehicle, etc.) that contains a battery that needs to be charged by an external source.

According to a second aspect of the present invention, there is provided a method for positioning a moving component relative to a stationary component as set out in the appended claims. The method according to the invention comprises the following steps: a first trajectory for positioning the moving component, e.g., from a first position distal from the stationary component, to a second position proximal to the stationary component is determined based on sensing a relative position between the moving component and the stationary component based on the wireless signal. The wireless signal may be generated by a first position sensor, as described above. The moving component is displaced from a first position to a second position based on the first trajectory. After the shifting is completed, a calibration offset for the first trajectory is determined. The calibration offset is determined based on sensor data that is different from the wireless signal and that is collected on or within the moving component during the performance of the displacement. Advantageously, the sensor data refers to the collection of second data by one or more second sensors as described above.

It is advantageous to determine a second trajectory corresponding to a shift that has been performed, in particular from the first position to the second position, based on the sensor data. Advantageously, the calibration offset is determined based on a difference or deviation between the first trajectory and the second trajectory.

Advantageously, the method may comprise: the flag position of the mobile component relative to the stationary component is recorded, for example, by collecting third data different from the wireless signal, wherein the flag position is determined based on the third data. In determining the calibration offset, the first track and the second track are made to coincide at the marker position. The landmark location may, but need not, be the second location. Advantageously, timestamp information corresponding to at least a portion, or all, of: the first data, the second data, or both. The time stamp information helps to make the first track and the second track coincide at the mark position.

Advantageously, a method according to an aspect of the invention comprises collecting fourth data indicative of an orientation of the moving component relative to the stationary component. Advantageously, the second trajectory is determined taking into account the fourth data. Accordingly, a calibration offset may be determined based on the fourth data. The fourth data may be different from any or all of the wireless signal, the second data, the third data.

Advantageously, the calibration offset is determined by feeding the first trajectory and the second trajectory to a machine learning algorithm or an iterative convergence algorithm. For example, for the first trajectory T_iDetermining the corresponding calibration offset CO_i. Using calibration offset CO_iTo correct/adapt the subsequent first trajectory T_i+1。

Advantageously, the method according to the invention reflects the implementation of the controller of the system described above. Alternatively, a system as described above is caused to perform the method steps as described herein.

Entry (Clauses)

1. A system (30) for positioning a moving assembly (10) relative to a stationary assembly (20), or a system for guiding a moving assembly towards a stationary assembly, comprising:

a first position sensing device (40) configured to sense first data based on the wireless signal, the first data being indicative of a relative position between the moving component (10) and the stationary component (20);

a controller (31) configured to determine a first trajectory (103) based on the first data; and

at least one sensor (51, 53) attached to the moving assembly (10) and arranged for collecting second data representing a displacement performed by the moving assembly,

wherein the controller (31) is configured to determine a calibration offset (105) of the first trajectory (103) based on the second data, the controller being configured to determine a calibration offset after the moving component completes the displacement from the first position (101) along the first trajectory (103) to the second position (102), and wherein the controller is configured to guide the moving component (10) from the first position (101) away from the stationary component to the second position (102) close to the stationary component based on the first data and the calibration offset.

2. The system of item 1, wherein the controller is configured to determine a second trajectory (104) based on the second data, the second trajectory representing a shift performed by the moving component, the controller being configured to determine the calibration offset (105) based on a difference between the first trajectory (103) and the second trajectory (104).

3. The system of item 2, comprising means for recording a marker position of the moving component relative to the stationary component along the displacement, wherein the controller (31) is configured to determine the calibration offset by coinciding the first trajectory (103) and the second trajectory (104) at the mark position.

4. The system of clause 3, wherein the means for recording the marker position comprises a third sensor configured to collect third data indicative of the marker position, the third sensor being different from the position sensing device.

5. The system of clauses 3 or 4, wherein the second location is the flag location.

6. The system of any one of the preceding items, wherein the first position sensing device (40) is configured to emit an electromagnetic or ultrasonic signal for sensing the first data.

7. The system of any one of the preceding items, wherein the second position (102) is a parking position of the mobile assembly (10).

8. The system of item 7, wherein the second position allows the transfer of a common energy source between the moving component and the stationary component (20).

9. The system of item 8, wherein the transmission of the common energy source comprises transmission of electrical energy.

10. The system of any one of the preceding items, wherein the controller (31) implements a machine learning algorithm or an iterative convergence algorithm to determine a distortion compensation of the first position sensing device (40) as a function of the calibration offset (105).

11. The system of any one of the preceding items, wherein the controller (31) is configured to adapt a subsequent first trajectory based on the calibration offset (105).

12. The system of any one of the preceding items, wherein the at least one sensor (51, 53) is one or more of: an accelerometer, a gyroscope, a rotation angle sensor, a rotation speed sensor, and a steering angle sensor.

13. The system of any one of the preceding items, wherein the system is configured to collect fourth data representing an orientation of the moving component relative to the stationary component, wherein the controller is configured to determine the orientation along at least one position of the displacement and to determine the calibration offset based on the orientation.

14. The system of any one of the preceding items, wherein sensing first data based on the wireless signal comprises measuring a parameter of the wireless signal representative of the relative position.

15. A stationary assembly (20) comprising a system according to or for any of the preceding items.

16. A method (200) for positioning a moving assembly (10) relative to a stationary assembly (20), comprising the steps of:

determining a first trajectory (103) for positioning the moving component (10) from a first position (101) away from the stationary component (20) to a second position (102) close to the stationary component by sensing a relative position between the moving component and the stationary component based on a wireless signal,

performing a displacement of the moving component from the first position (101) to the second position (102) based on the first trajectory (103),

after the displacement is completed, a calibration offset (105) of the first trajectory (103) is determined based on sensor data collected on the moving assembly (10) during the execution of the displacement, the sensor data not being the wireless signal.

17. The method of item 16, comprising determining a second trajectory (104) based on the sensor data, the second trajectory representing a displacement performed by the moving component, wherein determining the calibration offset comprises evaluating a difference between the first trajectory (103) and the second trajectory (104).

18. The method of item 17, comprising recording a marker position of the moving component relative to the stationary component along the displacement, wherein determining the calibration offset (105) comprises coinciding the second trajectory with the first trajectory (103) at the marker position.

19. The method of item 18, comprising collecting third data different from the wireless signal and using the third data to record the marker location.

20. The method of item 18 or 19, wherein the flag location is the second location.

21. The method of any of items 16 to 20, wherein the second position (102) is a parking position of the mobile assembly.

22. The method of item 21, wherein the parked position allows a common energy source to be transferred between the moving component and the stationary component.

23. The method of item 22, wherein transmitting the common energy source comprises transmitting electrical energy.

24. The method of any of items 16 to 23, comprising collecting fourth data indicative of the orientation of the moving component relative to the stationary component, and determining the calibration offset based on the fourth data.

25. The method of item 24 in combination with any one of items 17-20, comprising determining the second trajectory based on the fourth data.

26. The method of any of the items 16 to 25, wherein the calibration offset (105) is determined by feeding it to a machine learning algorithm or an iterative convergence algorithm.

27. The method of any of items 16 to 26, comprising adjusting a subsequent first trajectory (103) based on the calibration offset (105) when determining the first trajectory.

28. The method of any one of claims 15-27, wherein sensing the relative position includes measuring a parameter of the wireless signal.

Drawings

Aspects of the present invention will now be described in more detail, with reference to the appended drawings, wherein like reference numerals represent like features, and wherein:

FIG. 1 illustrates a first trajectory for guiding a moving assembly away from a first position of a stationary assembly to a second position proximate to the stationary assembly;

FIG. 2 schematically illustrates a moving assembly and a stationary assembly with components mounted thereon;

FIG. 3 shows the first trajectory of FIG. 1 (which is an estimated trajectory), and an actual execution trajectory determined from sensor data collected on the moving assembly;

FIG. 4 shows a flow chart of a method for positioning a moving component relative to a stationary component in accordance with the present invention.

Detailed Description

Referring to fig. 1, when a moving assembly 10 (such as an electric vehicle) needs to be positioned in alignment with a stationary assembly 20, the moving assembly must typically perform a routing maneuver from a current location 101 to a final parked location 102. The moving assembly 10 needs to execute a trajectory 103 from the current position 101 to the final parking position 102. The stationary component may be the following: allowing for the transmission of various common energy sources, such as but not limited to electrical energy, between the mobile assembly 10 and the stationary assembly 20, which may be achieved through a wireless interface (e.g., inductive power transfer) or through a wired connection. The transfer of the common energy source may also involve, for example, automatic loading or unloading of cargo into and out of the mobile assembly.

Referring to fig. 2 and 3, the positioning system 30 includes a control unit 31 and a position sensing system 40 coupled thereto. The position sensing system 40 includes position sensors, such as a transmitter 41 and a receiver 42, configured to sense the position of the moving assembly 10 relative to the stationary assembly 20. The position information sensed by the position sensing system 40 is fed to a control unit 31 configured to calculate and possibly track/monitor the trajectory 103. For example, the transmitter 41 is disposed on the stationary component 20 and the receiver 42 is disposed on the moving component, or vice versa. Alternatively, the transmitter 41 and/or the receiver 42 may be a transceiver configured to transmit and receive wireless signals. The position sensing system 40 is configured to sense a position based on the wireless signals. Any suitable type of wireless signal (such as an ultrasonic or acoustic signal, radio waves, magnetic fields, etc.) may be used for this purpose. It is convenient to note that the position sensing system 40 may not require position sensors on both the moving and stationary components. For example, a position sensor may be provided on only one of the moving component and the stationary component.

In one example, the control unit 31 is provided on the stationary assembly 20, but this is not essential and it is likely that the control unit 31 is provided on the moving assembly 10. The trajectory 103 determined by the control unit 31 is transmitted wirelessly (e.g. via a wireless communication interface 33 comprising communication antennas 32, 52) to the mobile assembly 10, the trajectory 103 being transmitted via the wireless communication interface to the control unit 50 on the mobile assembly. The control unit 50 may be configured to provide driving or guiding instructions to the mobile assembly 10, or to an operator driving the mobile assembly, based on the trajectory 103. It is convenient to note that alternatively, the control unit 50 may calculate the trajectory 103 based on position data fed to the control unit 50 by a position sensor (e.g., the receiver 42).

The signals from the position sensors of the position sensing system 40 may be distorted by the environment. For example, when using a magnetic field-based position sensing system, nearby magnetically permeable or electrically conductive materials may dampen or reflect the magnetic field. In the case of ultrasound-based systems, sound reflections from nearby objects may distort the received signal. Thus, the position signal provided by a position sensing system calibrated in a laboratory environment deviates from the actual position in the installation environment.

According to the invention, the accuracy of the position calculation is improved by a calibration of the environment and a compensation of the calculated position based on this calibration. The present invention uses sensor data of the secondary system, which describes (a part of) the relative trajectory performed, provided on the moving assembly 10 to calibrate or adjust the trajectory 103 determined by the control unit 31.

For this purpose, the moving assembly 10 is equipped with sensors 51, 53, such as accelerometers, (rotational) speed sensors, gyroscopes, wheel encoders or other sensing systems for parking assistance, parking distance control or automatic driving, which are typically present on moving assemblies, such as vehicles. The sensors 51, 53 are coupled to a control unit 50 which may process data received from these sensors to determine an execution trajectory 104 which may deviate from the calculated trajectory 103 (see fig. 3), for example because the environment causes distortion of the position data sensed by the position sensing system 40.

Advantageously, the sensors 51, 53 are used in the present invention as a secondary position sensing system for determining the second trajectory 104 in relation to the path actually performed by the mobile assembly 10. This trajectory 104 data is then used to correct or calibrate the calculated trajectory 103 after the moving assembly has completed its displacement to the final parking position 102.

In one aspect, a relative trajectory is obtained because the second trajectory 104 is determined based on sensors located on the moving assembly 10. Advantageously, in order to determine the error between the actual execution trajectory 104 and the calculated trajectory 103, the two trajectories are aligned at the marker position 106. Advantageously, the landmark locations refer to locations where the positioning system 30 may obtain accurate location information that is not affected by the environment. The location 106 may be identified, for example, by a beacon 60 determination that does not form part of the location sensing system 40 and/or the sensors 51, 53. The flag position 106 may be selected as the following: the distance between the moving component 10 and the stationary component 20 is very small, such as when the moving component 10 is aligned with the stationary component 20, for example, but not necessarily so, the index position 106 may coincide with or be adjacent to the park position 102, as shown in fig. 3.

Advantageously, the orientation α of the mobile assembly 10 is determined along the path performed. The orientation is determined at least one location along the first trajectory 103, the second trajectory 104, or both, and can be used to refine the determination of the corresponding trajectory relative to the stationary assembly 20. The orientation a may be determined by data collected by any of the position sensing system 40, the sensors 51, 53 or any other (additional) sensors.

Advantageously, the control unit 50 is configured to transmit the data representative of the execution trajectory 104 only after the mobile assembly 10 has reached the final position 102. The positioning system 30 may derive a calibration offset 105 based on the calculated/estimated trajectory 103 and the executed trajectory 104 (e.g., data collected by the sensors 51, 53). Since the stationary assembly 20 is typically fixed at a location within the garage or on a roadway, the calibration offset 105 may be refined over time when the mobile assembly 10 is parked at the location 102 multiple times, and/or according to the calibration offsets determined for multiple mobile assemblies. This will gradually take into account the (fixed) environmental impact. Preferably, the control unit 31 may be implemented with an iterative convergence algorithm or a machine learning algorithm based on the calibration offset 105 for gradually adjusting and improving the calculation of the trajectory 103. A asymptotic convergence algorithm is preferred to limit the influence of outliers in the position estimates of the first and second positioning systems. In other words, this prevents large deviations between subsequent position estimates.

Referring to fig. 4, a method 200 for positioning a mobile assembly 10 according to the present invention may include the following steps, which are advantageously performed sequentially. In a first optional step 201, the mobile component 10 located at the position 101 starts an initial communication with the stationary component 20, for example to establish a communication link. This may, for example, inform the stationary component 20 that the moving component wants to perform a parking maneuver to align with the stationary component 20 at location 102. The control unit 50 may transmit this information to the control unit 31 via the wireless communication interface 33. In this step, time information may be synchronized between the moving component and the stationary component.

In step 202, the first trajectory 103 is determined. The control unit 31 may activate the position sensing system 40 to determine the position 101 at which the moving component is located. From this position, the control unit 31 determines a first trajectory 103 followed by the mobile assembly 10 to reach the parking position 102. The trajectory 103 is transmitted to the control unit 50 on the moving assembly 10. In addition, the control unit may determine the orientation of the moving assembly 10 at the position 101, for example by the position sensing system 40, and use this orientation to determine the trajectory 103.

In step 203, the moving assembly 10 is displaced from position 101 to position 102. The control unit 50 may guide the moving assembly 10 to perform the first trajectory 103 by autonomous driving or operation-assisted driving. The position sensing system 40 may continuously guide the moving assembly by updating the position of the moving assembly 10 and adapting the first trajectory 103 accordingly. While executing the first trajectory 103, the control unit 50 collects data relating to the actual execution trajectory, for example from the sensors 51, 53.

In step 204, the marker position 106 is determined along the actual execution path, for example by the beacon 60. For example, a timestamp of when the moving component 10 passed the flag location 106 is determined, and the flag location 106 may refer to a known location relative to the stationary component 20 (the second location 102). Additionally or alternatively, the orientation α of the moving assembly 10 is determined along the path. The index position 106 and/or the orientation alpha are fed to the control unit 31.

In step 205, the mobile assembly 10 reaches the final parking position 102 and completes the first trajectory 103. The control unit 50 may transmit the collection trajectories received from the sensors 51, 53 to the control unit 31. Alternatively, data from the sensors 51, 53 may be transmitted to the control unit 31 during execution of the first trajectory 103.

In step 206, the control unit 31 determines the calibration offset 105. The control unit 50, or the control unit 31, may determine a second trajectory 104 representing the path actually performed by the moving assembly 10. The second trajectory 104 is determined using data collected from the sensors 51, 53 and optionally the orientation alpha. The second track 104 includes the location 102 as, for example, an endpoint of the track, and may include a marker location 106, which may or may not overlap with the location 102. Advantageously, the second trajectory 104 is not determined using data from the position sensing system 40. The control unit 31 may compare the second trajectory 104 of the position sensing system 40 with the first trajectory 103 to derive the calibration offset.

Once the mobile assembly reaches the final parking position 102, the difference between the first trajectory 103 and the second trajectory 104 may be determined. Advantageously, the first track 103 and the second track 104 are made to coincide at the marker position 106, and the deviation between the two can be easily determined. For example, the first track 103 and the second track 104 are aligned at the marker position 106. Since the time at which the mobile assembly 10 reaches the index position 106 is known, the entire second trajectory 104 may be related to the first trajectory 103. Depending on the accuracy of the position estimate of the first trajectory, the position estimated position of the position sensing system 40 may be updated (recalibrated) using machine learning techniques or iterative convergence algorithms in order to improve subsequent position estimates and/or trajectory determinations of the position sensing system 40.