Feed-forward calibration method, feed-forward calibration device and computer readable storage medium

Abstract

The invention provides a feedforward calibration method for transverse control of a vehicle, and the method comprises the following steps: S10, obtaining driving information under the condition that the vehicle is controlled by a driver to run through a curve, and manual operation information which is received by a steering wheel of the vehicle and is operated by the driver, the driving information comprises road feature information and / or vehicle speed information; and S20, according to the driving information and the manual operation information obtained in the step S10, the calibration relation between the feed-forward control quantity and the road characteristics and / or the vehicle speed is determined or adjusted, and the calibration relation is used for determining the feed-forward control quantity used for executing automatic transverse control under the condition that the vehicle is controlled by an automatic transverse control system of the vehicle to drive and pass through a curve. The invention further provides a corresponding calculator readable storage medium and a feed-forward calibration device. According to the invention, the calibration process is more convenient to realize, and the calibration accuracy is improved.

Description

Technical Field

[0001] The present invention relates to a feedforward calibration method for lateral control of a vehicle, a computer-readable storage medium, and a feedforward calibration device for lateral control of a vehicle. Background Art

[0002] Lateral control of a vehicle is an important aspect of assisted driving or autonomous driving. For example, a vehicle may have a lane keeping assist function, which can control the vehicle's steering system to assist the vehicle in staying within its lane.

[0003] The lane keeping assist system can, for example, give a feedforward control amount for the vehicle to travel centered on the road at a current vehicle speed through open-loop control. For this purpose, it is necessary to pre-calibrate the feedforward control amount. This calibration process usually requires a professional driver to drive the vehicle on different roads and collect relevant data. The existing calibration process is relatively complex and time-consuming. In addition, there are often performance differences between different vehicles. If the calibration is inaccurate or not adapted to the vehicle, it will be difficult for the vehicle to reliably implement the automatic lateral control function. For example, when driving through a curve, the lane keeping assist function of the vehicle is difficult to keep the vehicle within its lane. However, once the calibration process is completed, even if the calibration result has a low degree of adaptation to the vehicle, it is difficult to debug it or it requires a high cost to debug it.

[0004] Therefore, it is desirable to provide an improved feedforward calibration method for lateral control of a vehicle. Summary of the Invention

[0005] The object of the present invention is to provide an improved feedforward calibration method for lateral control of a vehicle in order to overcome at least one of the above-mentioned deficiencies of the prior art.

[0006] According to a first aspect of the present invention, there is provided a feedforward calibration method for lateral control of a vehicle. The feedforward calibration method includes the following steps: S10, obtaining driving information and manual operation information about a driver's operation received by a vehicle's steering wheel when the vehicle is driven by a driver through a curve, the driving information including road feature information and / or vehicle speed information; and S20, determining or adjusting a calibration relationship between a feedforward control amount and road features and / or vehicle speed according to the driving information and manual operation information obtained in step S10, the calibration relationship being used to determine a feedforward control amount for performing automatic lateral control when the vehicle is controlled by its automatic lateral control system and driven through a curve.

[0007] Thus, the feedforward calibration device integrated in the vehicle can be used to automatically calibrate the feedforward control amount of the automatic lateral control based on the driver's operation. This helps to reduce the calibration time, make the calibration process easier to implement, and improve the calibration accuracy.

[0008] In particular, the calibration relationship obtained thereby has a high adaptability to the vehicle and / or the driver of the vehicle (especially the vehicle owner). Even if they have the same model or belong to the same batch, there are still performance differences between different vehicles. In addition, different drivers usually have different driving habits and preferences. Through the present invention, the adaptability of the calibration relationship to the vehicle and / or the driver of the vehicle can be improved.

[0009] According to an exemplary embodiment of the present invention, the feedforward control amount may include a feedforward steering wheel torque or a feedforward steering wheel angle.

[0010] According to an exemplary embodiment of the present invention, the manual operation information may represent the hand torque applied by the driver to the steering wheel when the vehicle is driven by the driver through a curve, and / or represent the steering wheel angle by which the steering wheel is rotated by the driver when the vehicle is driven by the driver through a curve.

[0011] According to an exemplary embodiment of the present invention, the calibration relationship between the feedforward control amount and the road characteristics and / or vehicle speed characteristics is stored in the form of an interpolation table.

[0012] According to an exemplary embodiment of the present invention, the calibration relationship between the feedforward control amount and the road characteristics and / or vehicle speed characteristics can be expressed as a functional relationship between the feedforward control amount and the road characteristics and / or vehicle speed characteristics. The functional relationship can be obtained by fitting.

[0013] According to an exemplary embodiment of the present invention, the feedforward calibration method may further include step S15 executed after step S10. In step S15, the lateral control operation of the vehicle driven by the driver through a curve can be evaluated according to the driving information obtained in step S10. Step S20 is continued only when the lateral control operation meets a predetermined condition.

[0014] According to an exemplary embodiment of the present invention, in step S15, the predetermined conditions may include: the lateral deviation amount is less than a predetermined lateral deviation threshold; and / or, the heading angle deviation is less than a predetermined heading angle deviation threshold; and / or, the steering wheel angle rate is less than a predetermined angle rate threshold.

[0015] According to an exemplary embodiment of the present invention, in step S01, the feedforward calibration mode can be started in response to the user's start operation. Steps S10 and S20 are executed when the feedforward calibration mode is started, and step S20 is not executed when the feedforward calibration mode is not started.

[0016] According to an exemplary embodiment of the present invention, the feedforward calibration method may include step S02, in which, after the feedforward calibration mode is activated, prompt information is provided to the driver by means of an interaction device of the vehicle so as to guide the driver to control the vehicle to drive through a curve.

[0017] According to an exemplary embodiment of the present invention, the feedforward calibration method may include the following steps: S210, obtaining driving information in the case where the vehicle is controlled by an automatic lateral control system to drive through a curve and control information about a control signal applied by the automatic lateral control system to the steering wheel; and S220, determining or adjusting a calibration relationship between a feedforward control amount and a road feature and / or vehicle speed according to the driving information and the control information obtained in step S210, where the calibration relationship is used to determine a feedforward control amount for performing automatic lateral control in the case where the vehicle is controlled by its automatic lateral control system to drive through a curve.

[0018] According to a second aspect of the present invention, there is provided a computer-readable storage medium storing computer program instructions, wherein the computer program instructions, when executed by one or more processors, enable the one or more processors to execute the feedforward calibration method according to the present invention.

[0019] According to a third aspect of the present invention, there is provided a feedforward calibration device for lateral control of a vehicle, wherein the feedforward calibration device includes one or more processors; and a memory storing computer program instructions, the computer program instructions, when executed by the one or more processors, enabling the one or more processors to execute the feedforward calibration method according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Hereinafter, the present invention will be described in more detail by referring to the drawings, and the principles, features and advantages of the present invention can be better understood. The drawings include:

[0021] Figure 1 A vehicle provided with a feedforward calibration device according to an exemplary embodiment of the present invention is schematically shown;

[0022] Figure 2 A flowchart of a feedforward calibration method according to an exemplary embodiment of the present invention is schematically shown;

[0023] Figure 3 A flowchart of a feedforward calibration method according to an exemplary embodiment of the present invention is schematically shown;

[0024] Figure 4 A flowchart of a feedforward calibration method according to an exemplary embodiment of the present invention is schematically shown; and

[0025] Figure 5 A flowchart schematically showing some steps of a feedforward calibration method according to an exemplary embodiment of the present invention.

[0026] List of reference numerals

[0027] 11 Feedforward calibration device

[0028] 12 Detection device

[0029] 13 Automatic lateral control system

[0030] 14 Steering wheel Detailed implementation manners

[0031] In order to make the technical problems to be solved, technical solutions and beneficial technical effects of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the protection scope of the present invention.

[0032] Figure 1 A vehicle provided with a feedforward calibration device 11 according to an exemplary embodiment of the present invention is schematically shown. Figure 2 A flowchart of a feedforward calibration method according to an exemplary embodiment of the present invention is schematically shown.

[0033] As Figure 1 shown, in addition to the feedforward calibration device 11, the vehicle may also be provided with a detection device 12. The detection device 12 can be used to detect the vehicle and the surrounding environment. The detection device 12 may include, for example, a camera device, a radar sensor, a lidar sensor, a vehicle speed sensor or an angle sensor, etc.

[0034] The vehicle may be provided with an automatic lateral control system 13, which can be used to achieve automatic lateral control of the vehicle in the autonomous driving mode or the assisted driving mode. The automatic lateral control system 13 can be used to achieve, for example, the lane keeping assist function.

[0035] The automatic lateral control system 13 may include an automatic lateral control device and an actuator. The actuator may include, for example, an actuator of an electric power steering system (EPS). The automatic lateral control device can obtain detection information about the vehicle and the surrounding environment by means of the detection device 12, and control the actuator to adjust the driving direction of the vehicle based on the detection information.

[0036] For example, when the lane keeping assist function is turned on, the automatic lateral control system 13 can identify whether the vehicle deviates from the lane by means of the detection device 12, and make the vehicle travel in the lane according to the desired driving trajectory through the automatic lateral control device and the actuator.

[0037] As an example, the automatic lateral control system 13 can adjust control variables such as the magnitude of the steering wheel torque or the steering wheel angle through a combination of feedforward open-loop control and feedback closed-loop control, so that the vehicle travels in a desired driving direction (or driving trajectory).

[0038] The feedforward calibration device 11 is implemented as, for example, an electronic control unit (ECU) of the vehicle. The feedforward calibration device 11 may include a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the processor can, for example, execute a feedforward calibration method for an operation prediction method for the vehicle for lateral control of the vehicle. The computer program product can be stored in a computer-readable storage medium. The computer-readable storage medium may include, for example, a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card, a secure digital card, a flash memory card, at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0039] As Figure 2 shown, the feedforward calibration method may include step S10 and step S20.

[0040] In step S10, driving information in the case where the vehicle travels through a curve under the control of a driver and manual operation information about the operation received by the steering wheel 14 of the vehicle are acquired. The driving information includes road characteristic information and / or vehicle speed information.

[0041] In step S20, according to the driving information and the manual operation information acquired in step S10, the calibration relationship between the feedforward control variable and the road characteristics and / or the vehicle speed is determined or adjusted. The calibration relationship is used to determine the feedforward control variable for performing automatic lateral control in the case where the vehicle travels through a curve under the control of its automatic lateral control system 13.

[0042] In the case where the vehicle travels through a curve under the control of its automatic lateral control system 13, the automatic lateral control system 13 can determine the feedforward control variable for performing automatic lateral control according to the calibration relationship, so as to implement feedforward open-loop control of the driving direction of the vehicle by using the feedforward control variable.

[0043] Thus, the feedforward calibration device 11 integrated in the vehicle can be used to automatically calibrate the feedforward control variable of the automatic lateral control based on the operation of the driver. This helps to reduce the calibration time and improve the calibration accuracy.

[0044] In particular, the resulting calibration relationship has a high degree of suitability for the vehicle and / or the driver (especially the vehicle owner) of the vehicle. Even if they have the same model or belong to the same batch, there are still performance differences between different vehicles. Additionally, different drivers usually have different driving habits and preferences. Through the present invention, the suitability of the calibration relationship for the vehicle and / or the driver of the vehicle can be improved.

[0045] The feedforward calibration device 11 can, for example, be integrated with the automatic lateral control device in the same electronic control unit. The feedforward calibration device 11 is also implemented as a separate electronic control unit. The feedforward calibration device 11 can be communicatively connected to the automatic lateral control system 13, especially the automatic lateral control device of the automatic lateral control system 13.

[0046] "The vehicle is driven by the driver through a curve" means that the vehicle performs lateral control only in response to the operation applied by the driver to the steering wheel 14. In this case, the automatic lateral control system 13 or the lane keeping assist function is not enabled.

[0047] See Figure 1 , the feedforward calibration device 11 can be communicatively connected to the detection device 12 to obtain the detection information of the detection device 12. The feedforward calibration device 11 can, for example, send a detection instruction to the detection device 12 so that the detection device 12 can perform corresponding detection operations in response to the detection instruction.

[0048] The feedforward calibration device 11 can obtain driving information by means of the detection device 12. The driving information can especially include road characteristic information and vehicle speed information. The road characteristic information can, for example, include information indicating the curvature, radius of curvature, rate of change of curvature, slope, and / or surface flatness of the road, etc.

[0049] As an example, using the image captured by the camera device, the lane lines of the lane where the vehicle is located can be recognized. Furthermore, the curvature or radius of curvature of the road can be determined. The vehicle speed of the vehicle can be detected, for example, by a vehicle speed sensor.

[0050] In addition, the feedforward calibration device 11 can obtain manual operation information by means of the detection device 12. The manual operation information can, for example, represent the hand torque applied by the driver to the steering wheel 14 when the vehicle is driven by the driver through a curve. Alternatively or additionally, the manual operation information can represent the angle by which the steering wheel 14 is rotated by the driver when the vehicle is driven by the driver through a curve, that is, the steering wheel angle.

[0051] By driving a vehicle by a driver at different vehicle speeds on roads with different road characteristics, multiple sets of driving information and manual operation information can be correspondingly collected. Based on the multiple sets of driving information and manual operation information collected, the amount of operation to be applied according to the driver's experience can be determined under different road characteristics and / or vehicle speeds.

[0052] Optionally, the feedforward control amount may include a feedforward steering wheel torque or a feedforward steering wheel angle.

[0053] According to an exemplary embodiment of the present invention, in step S20, the calibration relationship between the feedforward control amount and the road characteristics and / or vehicle speed is determined, for example, such that at the same road characteristics and / or vehicle speed, the calibrated feedforward control amount is less than the amount of operation to be applied according to the driver's experience. This helps to improve driving safety and the riding experience of the vehicle. For example, at the same road characteristics and vehicle speed, the calibrated feedforward steering wheel torque may be 75% to 85%, especially 80%, of the hand torque to be applied according to the driver's experience.

[0054] The calibration relationship is stored, for example, in the form of an interpolation table.

[0055] Optionally, the calibration relationship can be expressed as a functional relationship between the feedforward control amount and the road characteristics and / or vehicle speed characteristics. The functional relationship can be obtained by fitting.

[0056] The calibration relationship is stored, for example, in the memory of the feedforward calibration device 11. Alternatively, the feedforward calibration device 11 can send the determined calibration relationship to the automatic lateral control device of the automatic lateral control system 13 so that the calibration relationship is stored in the automatic lateral control device.

[0057] When the vehicle is controlled by the automatic lateral control system 13 and travels through a curve, the automatic lateral control system 13 can call the calibration relationship to determine the feedforward control amount. For example, the feedforward control amount can be obtained based on the road curvature at the current preview point of the vehicle and the current vehicle speed.

[0058] In addition, the automatic lateral control device of the automatic lateral control system 13 can use a feedback control loop to determine a feedback control amount for the lateral control of the vehicle based on the heading angle deviation and / or lateral distance deviation of the vehicle. The automatic lateral control device can jointly provide the feedback control amount and the feedforward control amount to the actuator to achieve the lateral control of the vehicle. Alternatively, the automatic lateral control device can fuse the feedback control amount and the feedforward control amount to obtain a control signal for the lateral control of the vehicle, and then provide it to the actuator to achieve the automatic lateral control of the vehicle.

[0059] Figure 3 Schematically shows a flowchart of a feedforward calibration method according to an exemplary embodiment of the present invention. Figure 2Similarly, the illustrated embodiments Figure 3 The illustrated feedforward calibration method may include step S10 and step S20.

[0060] The feedforward calibration method may further include step S15, which is performed after step S10. In step S15, a lateral control operation of the vehicle traveling through a curve under the control of a driver may be evaluated based on the driving information obtained in step S10. Step S20 is continued only if the lateral control operation meets a predetermined condition.

[0061] Thus, only when the lane keeping degree and / or driving smoothness during the process of the vehicle traveling through a curve under the control of a driver are good, the calibration relationship is determined or adjusted based on the driving information and manual operation information of this process. This helps to automatically determine or adjust the calibration relationship according to the driving process of the driver during the use of the vehicle. This allows the calibration process to be achieved without the driver's special attention. For example, during the normal use of the vehicle by the vehicle owner, the feedforward calibration device 11 can automatically identify that a certain lateral control operation of the vehicle traveling through a curve under the control of a driver meets a predetermined condition, and determine or adjust the calibration relationship based on this lateral control operation.

[0062] The predetermined condition may, for example, include that the lateral deviation amount is less than a predetermined lateral deviation threshold.

[0063] Alternatively or additionally, the predetermined condition may include that the heading angle deviation is less than a predetermined heading angle deviation threshold.

[0064] Optionally, the predetermined condition may include that the steering wheel angle rate is less than a predetermined angle rate threshold.

[0065] The predetermined condition may, for example, further include that the curvature of the road is greater than a predetermined curvature threshold or the slope of the road is less than a predetermined slope threshold, etc.

[0066] Figure 4 Schematically shows a flowchart of a feedforward calibration method according to an exemplary embodiment of the present invention.

[0067] As Figure 4 shown, the feedforward calibration method may include step S01. In step S01, in response to a start operation of a user, a feedforward calibration mode is started. Step S10 and step S20 are performed when the feedforward calibration mode is started. Step S20 is not performed at least when the feedforward calibration mode is not started. Thus, an optional feedforward calibration function can be provided for the vehicle. The feedforward calibration function of the vehicle can be started as needed, thereby preventing the calibration relationship from being undesirably changed. This helps to improve the use experience. For example, the vehicle owner can perform personalized settings on the automatic lateral control of the vehicle as needed.

[0068] The startup operation of the user may include, for example, pressing a physical button or a virtual button on the vehicle, issuing a voice command to start the feedforward calibration mode, or performing an operation on a mobile device associated with the vehicle, etc.

[0069] Steps S10 and S20 can be executed in a similar manner as Figure 2 Steps S10 and S20 in the illustrated embodiment, and will not be elaborated here.

[0070] Optionally, the feedforward calibration method may include step S21. In step S02, after the feedforward calibration mode is started, prompt information is provided to the driver by means of the vehicle's interaction device to guide the driver to control the vehicle to drive through a curve. The driver can perform a lateral control operation that meets the predetermined conditions under the guidance of the prompt information. Therefore, even if the driver does not have relevant professional knowledge, they can achieve feedforward calibration under the guidance of the prompt information.

[0071] The interaction device may include, for example, a display device or a voice playback device, etc.

[0072] The prompt information may include, for example, the road condition requirements applicable to feedforward calibration. For example, the driver can be guided by the prompt information to control the vehicle to drive on a road surface with high surface flatness and approximately horizontal, so as to obtain a reliable calibration relationship through the feedforward calibration device 11.

[0073] Optionally, the prompt information may include the driving operation requirements applicable to feedforward calibration. For example, the driver can be guided by the prompt information to control the vehicle to drive smoothly approximately in the middle of the lane, so as to obtain a reliable calibration relationship through the feedforward calibration device 11.

[0074] Figure 5 A flowchart schematically showing some steps of the feedforward calibration method according to an exemplary embodiment of the present invention is shown.

[0075] As Figure 5 shown, the feedforward calibration method may include steps S210 and S220.

[0076] In step S210, the driving information in the case where the vehicle is controlled by the automatic lateral control system 13 to drive through a curve and the control information about the control signal applied by the automatic lateral control system 13 to the steering wheel 14 can be obtained.

[0077] In step S220, the calibration relationship between the feedforward control amount and the road characteristics and / or vehicle speed can be determined or adjusted according to the driving information and control information obtained in step S210.

[0078] The control information may represent, for example, the control signal for the lateral control of the vehicle obtained by the automatic lateral control system 13 by fusing the feedback control amount and the feedforward control amount.

[0079] In step S220, the calibration relationship between the feedforward control amount and the road characteristics and / or vehicle speed is determined, for example, such that at the same road characteristics and / or vehicle speed, the calibrated feedforward control amount can be less than the control amount that would be applied according to the experience of the automatic lateral control system 13, for example, it can be reduced by 20%.

[0080] It should be understood that when describing the exemplary embodiments, the specification may describe the feedforward calibration method in a specific step sequence, or the flowchart may present the feedforward calibration method in a specific step sequence. However, in the case where the feedforward calibration method does not depend on the specific sequence of the steps described herein, the feedforward calibration method should not be limited to the specific sequence of steps described. As those of ordinary skill in the art will understand, other step sequences are possible. Therefore, the specific sequence of steps set forth in the specification should not be construed as a limitation on the claims. In addition, the claims directed to the feedforward calibration method should not be limited to performing their steps in the written order, and these orders can be varied and still fall within the scope of the present application.

[0081] The features and advantages described herein for the feedforward calibration method are also applicable to the feedforward calibration device, and vice versa.

[0082] Although specific embodiments of the present invention are described in detail herein, they are given for illustrative purposes only and should not be considered as limiting the scope of the present invention. Various substitutions, alterations, and combinations can be conceived without departing from the spirit and scope of the present invention. The features of the embodiments can be separated or combined to form additional embodiments not explicitly described or illustrated herein, which still fall within the protection scope of the present invention.

Claims

1. A feedforward calibration method for lateral control of a vehicle, wherein, The feedforward calibration method includes the following steps: S10. Obtain driving information when the vehicle is driven by a driver through a curve and manual operation information about the driver's operation received by the vehicle's steering wheel. The driving information includes road feature information and / or vehicle speed information; and S20. Determine or adjust the calibration relationship between the feedforward control amount and the road feature and / or vehicle speed according to the driving information and manual operation information obtained in step S10. The calibration relationship is used to determine the feedforward control amount for performing automatic lateral control when the vehicle is driven by its automatic lateral control system through a curve.

2. The feedforward calibration method according to claim 1, wherein the feedforward control amount includes a feedforward steering wheel torque or a feedforward steering wheel angle; and / or the manual operation information represents the hand torque applied by the driver to the steering wheel when the vehicle is driven by the driver through a curve, and / or represents the steering wheel angle by which the steering wheel is rotated by the driver when the vehicle is driven by the driver through a curve.

3. The feedforward calibration method according to claim 1 or 2, wherein the calibration relationship between the feedforward control amount and the road feature and / or vehicle speed feature is stored in the form of an interpolation table; and / or the calibration relationship between the feedforward control amount and the road feature and / or vehicle speed feature is expressed as a functional relationship between the feedforward control amount and the road feature and / or vehicle speed feature, and the functional relationship is obtained by fitting.

4. The feedforward calibration method according to any one of claims 1-3, wherein the feedforward calibration method further includes step S15 executed after step S10. In step S15, according to the driving information obtained in step S10, evaluate the lateral control operation when the vehicle is driven by the driver through a curve, and continue to execute S20 only when the lateral control operation meets a predetermined condition.

5. The feedforward calibration method according to claim 4, wherein in step S15, the predetermined conditions include: the lateral deviation amount is less than a predetermined lateral deviation threshold; and / or the heading angle deviation is less than a predetermined heading angle deviation threshold; and / or the steering wheel angle rate is less than a predetermined angle rate threshold.

6. The feedforward calibration method according to any one of claims 1-5, wherein the feedforward calibration method includes step S01. In step S01, in response to the user's start operation, start the feedforward calibration mode. When the feedforward calibration mode is started, execute step S10 and step S20. When the feedforward calibration mode is not started, do not execute step S20.

7. The feedforward calibration method according to claim 6, wherein the feedforward calibration method includes step S02. In step S02, after the feedforward calibration mode is started, provide prompt information to the driver by means of the vehicle's interaction device to guide the driver to drive the vehicle through a curve.

8. The feedforward calibration method according to any one of claims 1-7, wherein the feedforward calibration method includes the following steps: S210, obtain driving information when the vehicle is driving through a curve under the control of the automatic lateral control system and control information regarding the control signal applied by the automatic lateral control system to the steering wheel; and S220, based on the driving information and control information obtained in step S210, determine or adjust the calibration relationship between the feedforward control amount and the road characteristics and / or vehicle speed, the calibration relationship being used to determine the feedforward control amount for performing automatic lateral control when the vehicle is driving through a curve under the control of its automatic lateral control system.

9. A calculator-readable storage medium stores computer program instructions, wherein, When executed by one or more processors, the computer program instructions enable the one or more processors to execute the feedforward calibration method according to any one of claims 1-8.

10. A feedforward calibration device for lateral control of a vehicle, wherein, The feedforward calibration device includes one or more processors; and a memory storing computer program instructions, which when executed by the one or more processors enable the one or more processors to execute the feedforward calibration method according to any one of claims 1-8.

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