Transmission output compensation method, related equipment and electric power steering system

Abstract

The present invention relates to the field of transmission technology, and provides a transmission output compensation method, related equipment and an electric power steering system. The transmission output compensation method is applied to a transmission system including a rack and pinion steering gear, and includes: obtaining a functional relationship between the rack output force and the input torque and the rack stroke; obtaining the rack resistance of the rack in each stroke segment; wherein the functional relationship and the rack resistance are periodically updated respectively; in response to the current input torque, the driving force of the input shaft is kept unchanged, the current rack stroke and the current rack output force are determined according to the current input torque and the functional relationship, the current rack resistance is determined according to the current rack stroke, and the driving force of the power-assisting mechanism is determined according to the current rack output force, the current rack resistance and the driving force of the input shaft. The present invention can solve the problem that the change in transmission resistance caused by the mechanical aging of components and changes in the environment in which the vehicle is located affects the driver's feel, improve driving comfort, and ensure the reliability of the transmission system.

Description

Technical Field

[0001] The present invention relates to the field of transmission technology, in particular to a transmission output compensation method, related equipment and an electric power steering system. Background Art

[0002] In a transmission system equipped with a rack and pinion steering gear, the gear is connected to the steering wheel through an intermediate transmission shaft and an input shaft in sequence. The intermediate transmission shaft can be connected to a power-assist mechanism, and the rack is connected to the steering wheel. When the driver applies input torque through the steering wheel, the input shaft provides driving force, and the power-assist mechanism provides power to drive the gear to rotate and then drive the rack to move linearly. The rack pushes the steering wheel to swing to achieve steering. Among them, the rack output force determines the load-carrying capacity of the transmission system, that is, determines the steering action of the vehicle.

[0003] As the mechanical parts of the transmission system wear and age with use, the transmission resistance between the parts changes. The output force of the rack is determined by the driving force of the input shaft, the power assist of the power assist mechanism, and the transmission resistance between the parts. When the transmission resistance changes, the input torque required to produce the same steering action changes, resulting in a change in the driver's feel.

[0004] At present, mechanical tuning is usually adopted to adjust the input torque required to achieve a certain steering action by adjusting the spring force of the input shaft, the tightening force of the bolts, etc. However, this cannot fundamentally solve the problem that the changes in transmission resistance caused by the mechanical aging of components and changes in the vehicle's environment affect the driver's feel.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In view of this, the present invention provides a transmission output compensation method, related equipment (including a transmission output compensation device, an electronic device, a computer-readable storage medium, a computer program product) and an electric power steering system, which can solve the problem that changes in transmission resistance caused by mechanical aging of components and changes in the vehicle's environment affect the driver's feel.

[0007] According to one aspect of the present invention, there is provided a transmission output compensation method, which is applied to a transmission system including a rack and pinion steering gear, wherein the gear is connected to an input shaft and is connected to a power assist mechanism, and the transmission output compensation method comprises: obtaining a functional relationship between the rack output force and the input torque and the rack stroke, wherein the rack stroke and the rack output force change with changes in the input torque; obtaining the rack resistance of the rack in each stroke segment; wherein the functional relationship and the rack resistance are periodically updated respectively; in response to a current input torque, keeping the driving force of the input shaft unchanged, determining the current rack stroke and the current rack output force according to the current input torque and the functional relationship, determining the current rack resistance according to the current rack stroke, and determining the driving force of the power assist mechanism according to the current rack output force, the current rack resistance and the driving force of the input shaft.

[0008] By periodically obtaining the functional relationship between the rack output force, input torque and rack travel, the change in the relationship between the rack output force and input torque caused by the change in transmission resistance is learned, so as to overcome the problem of the same input torque causing the difference in rack output force caused by mechanical aging of components; among them, in the gear rack steering transmission system, the difference and change of rack resistance in different travel segments are particularly obvious, so by periodically obtaining the rack resistance of the rack in each travel segment, the change of rack resistance with travel and use is mastered. When the current input torque is received, the driving force of the input shaft is kept unchanged, so that the input feel fed back to the driver remains unchanged, and the driving force of the power-assisting mechanism is adjusted according to the functional relationship of the corresponding cycle and the rack resistance of the corresponding cycle and travel segment, so as to achieve the output of the transmission system while supporting the driving force of the input shaft unchanged, so that the steering action of the vehicle matches the steering intention of the driver.

[0009] Therefore, the transmission output compensation method of the present invention effectively solves the problem that changes in transmission resistance caused by mechanical aging of components and changes in the vehicle's environment affect the driver's feel, can improve driving comfort, and ensure the safety and reliability of the transmission system.

[0010] In some embodiments, obtaining the functional relationship between the rack output force and the input torque and the rack stroke includes: when the transmission system is at an update node of the functional relationship: in response to a clockwise input torque manually applied to the input shaft, collecting clockwise data including the clockwise input torque and the corresponding rack stroke and rack output force, and fitting the functional relationship in the clockwise state according to the clockwise data; in response to a counterclockwise input torque manually applied to the input shaft, collecting counterclockwise data including the counterclockwise input torque and the corresponding rack stroke and rack output force, and fitting the functional relationship in the counterclockwise state according to the counterclockwise data; selecting the functional relationship that feels comfortable between the functional relationship in the clockwise state and the functional relationship in the counterclockwise state as the functional relationship within the corresponding period.

[0011] Each time the functional relationship of the transmission system is updated, the steering wheel is turned to apply input torque to the input shaft. The functional relationship between the rack output force and the input torque and rack stroke in the clockwise and counterclockwise states is fitted respectively, and the functional relationship with comfortable hand feeling is selected therefrom. This effectively solves the problem of unbalanced input torque required clockwise and counterclockwise due to mechanical wear, so that the driver can feel the same when applying input torque clockwise and counterclockwise during vehicle driving.

[0012] In some embodiments, the collection includes clockwise data of the clockwise input torque and the corresponding rack stroke and rack output force, including: collecting a group of clockwise data including continuous clockwise input torque and the corresponding rack stroke and rack output force; repeatedly collecting multiple groups of clockwise data; wherein, if there is a rack output force corresponding to the clockwise input torque in each group of collected clockwise data that differs by more than a set threshold, then the collected groups of clockwise data are discarded and the clockwise data are collected again.

[0013] The steering wheel can be rotated continuously clockwise, for example, more than two circles, to collect a set of clockwise data including continuous clockwise input torque and corresponding rack stroke and rack output force; in the case that the collected sets of clockwise data fluctuate greatly, the collected data is discarded and re-collected to avoid affecting the accuracy of the functional relationship obtained in the clockwise state.

[0014] In some embodiments, during the process of collecting the clockwise data and the counterclockwise data, the vehicle is kept in a parking state, and the rack moves through the clockwise travel segment and the counterclockwise travel segment respectively.

[0015] Update the functional relationship in the parking state to ensure that the driver feels comfortable when turning the steering wheel while the vehicle is driving. Make the rack move through the clockwise and counterclockwise travel segments respectively to ensure that the obtained functional relationship covers the full travel of the rack, that is, covers various steering scenarios during vehicle driving.

[0016] In some embodiments, in response to the current input torque, the driving force of the input shaft is maintained at the initial driving force; wherein, the driving force of the input shaft corresponding to the functional relationship of hand comfort collected when the transmission system is installed in the vehicle and started for the first time is used as the initial driving force.

[0017] The driving force of the input shaft corresponding to the functional relationship of the comfortable feel collected when the transmission system is installed in the vehicle and started for the first time is used as the initial driving force of the input shaft to ensure that the input feel of the input torque applied during the subsequent driving of the vehicle maintains the initial comfortable feel unchanged.

[0018] In some embodiments, the functional relationship is periodically updated based on the mileage of the vehicle; and within each cycle of the functional relationship, the rack resistance of the rack in each travel segment is periodically updated.

[0019] As the vehicle's mileage increases, the functional relationship between the rack output force and the input torque is periodically updated to overcome the problem of different rack output forces caused by the same input torque due to mechanical aging of the transmission components. Compared with the overall slow change in the transmission resistance of the rack and pinion steering transmission system, the resistance difference and change of the rack in different travel sections are more obvious. Therefore, in each cycle of the functional relationship, the rack resistance of the rack in each travel section is periodically updated.

[0020] In some embodiments, the rack output force is collected by a strain collection circuit, which includes: a strain gauge sensor, which is arranged on the rack; a feedback circuit, which includes an operational amplifier, wherein two input ends of the operational amplifier are respectively connected to two ends of the strain gauge sensor, and the output end of the operational amplifier outputs the rack output force.

[0021] The rack output force of the transmission system is collected through the strain collection circuit so that the functional relationship between the rack output force and the input torque can be adjusted as needed.

[0022] In some embodiments, obtaining the rack resistance of the rack in each stroke segment includes: when the transmission system is at an update node of the rack resistance: driving the rack to move to an end position of a stroke segment, wherein each stroke segment is formed by dividing the full stroke of the rack; driving the input shaft clockwise and counterclockwise respectively, and collecting a set of resistance values ​​of the reciprocating motion of the rack at the end position; obtaining the average of the multiple resistance values ​​as the rack resistance of the rack in the stroke segment within the corresponding period.

[0023] According to the rack motion characteristics, for example, the number of steering wheel rotations, the rack full stroke can be divided into multiple stroke segments. When the rack resistance is updated, the rack is reciprocated at the end position of each stroke segment to detect the rack resistance of the rack in each stroke segment.

[0024] In some embodiments, during the process of collecting a set of resistance values ​​for the reciprocating motion of the rack at the end position: if the resistance value collected during clockwise drive differs from the resistance value collected during counterclockwise drive by more than a predetermined value, the collected resistance value is discarded and the resistance value is collected again; if among multiple sets of resistance values ​​collected consecutively, the resistance value during clockwise drive and the resistance value during counterclockwise drive of each set differ from each other by more than a predetermined value, the average of the multiple sets of resistance values ​​is taken as the rack resistance of the rack in the stroke segment during the corresponding period.

[0025] When the resistance value collected during clockwise driving fluctuates greatly with the resistance value collected during counterclockwise driving, discard the collected data and collect again to avoid abnormal fluctuations in positive and negative rotation caused by non-rack transmission resistance affecting the accuracy of rack resistance. If there are multiple sets of resistance values ​​collected continuously for multiple times, and each set has a resistance value when clockwise driving and a resistance value when counterclockwise driving that differ by more than a predetermined value, the possibility of abnormal fluctuations in positive and negative rotation caused by non-rack transmission resistance can be ruled out, and the average of the multiple sets of resistance values ​​is taken as the rack resistance of the rack in the stroke section within the corresponding period.

[0026] In some embodiments, if the hand feeling of driving the rack to move to a stroke segment suddenly changes, the rack resistance of the rack in the stroke segment in the corresponding cycle is recovered.

[0027] In a certain travel section of the rack, if the driver's hand-felt input torque significantly increases or decreases, it is necessary to re-collect the rack resistance of the travel section to ensure that the rack resistance of the rack in the travel section within the corresponding cycle is accurate.

[0028] In some embodiments, determining the driving force of the power assist mechanism includes: M =F C +f-F I , where F M is the driving force of the assist mechanism, F Cis the current rack output force, f is the current rack resistance, F I is the driving force of the input shaft.

[0029] In order to ensure that the input torque input feel remains consistent during the vehicle's driving process, the driving force F of the input shaft I Keep the initial driving force unchanged; according to the functional relationship between the current input torque and the corresponding cycle, the current rack output force F can be determined C and the current rack travel, and then determine the current rack resistance f according to the rack resistance of the rack in each travel segment in the corresponding cycle and the travel segment that the current rack travel falls into. Then, the driving force F that the assist mechanism needs to provide under the current input torque can be determined. M , to achieve the driving force F on the supporting input shaft I While the rack output of the compensation transmission system remains unchanged, the current rack output force F C It can drive the vehicle's steering action to match the driver's steering intention.

[0030] An embodiment of the present invention further provides an electric power steering system, wherein the electric power steering system adopts the transmission output compensation method described in any of the above embodiments to determine the power output of the power motor.

[0031] The electric power steering system of the present invention adopts the above-mentioned transmission output compensation method, by periodically updating the functional relationship between the rack output force and the input torque, and periodically detecting the rack resistance of the rack in each travel section, accurately grasping the transmission resistance that affects the rack output force, so as to achieve that during the vehicle driving process, the driving force of the input shaft is kept unchanged so that the input feel fed back to the driver remains unchanged, and the driving force of the power-assisting mechanism is adjusted according to the functional relationship of the corresponding period and the rack resistance of the corresponding period and travel section, so as to achieve that while supporting the driving force of the input shaft unchanged, the output of the transmission system is compensated, so that the steering action of the vehicle matches the steering intention of the driver. Therefore, the electric power steering system of the present invention can effectively solve the problem that the change of transmission resistance caused by the mechanical aging of components and changes in the environment in which the vehicle is located affects the driver's feel, can improve driving comfort, and ensure the safety and reliability of the electric power steering system.

[0032] An embodiment of the present invention also provides a transmission output compensation device, which is applied to a transmission system including a rack and pinion steering gear, wherein the gear is connected to the input shaft and is connected to a power-assisting mechanism, and the transmission output compensation device is used to implement the transmission output compensation method as described in any of the above embodiments, including: a functional relationship learning module, used to obtain the functional relationship between the rack output force and the input torque and the rack stroke, wherein the rack stroke and the rack output force change with the change of the input torque; a rack resistance detection module, used to obtain the rack resistance of the rack in each stroke segment; wherein the functional relationship and the rack resistance are periodically updated respectively; a power-assisting output compensation module, used to keep the driving force of the input shaft unchanged in response to the current input torque, determine the current rack stroke and the current rack output force according to the current input torque and the functional relationship, determine the current rack resistance at least according to the current rack stroke, and determine the driving force of the power-assisting mechanism according to the current rack output force, the current rack resistance and the driving force of the input shaft.

[0033] An embodiment of the present invention further provides an electronic device, comprising: a processor; a memory, wherein the memory stores executable instructions; wherein when the executable instructions are executed by the processor, the transmission output compensation method as described in any of the above embodiments is implemented.

[0034] An embodiment of the present invention further provides a computer-readable storage medium for storing a program, and when the program is executed by a processor, the transmission output compensation method as described in any of the above embodiments is implemented.

[0035] An embodiment of the present invention further provides a computer program product, including a computer program. When the computer program is executed by a processor, the transmission output compensation method as described in any of the above embodiments is implemented.

[0036] The beneficial effects of the present invention compared with the prior art include at least:

[0037] The present invention periodically updates the functional relationship between the rack output force and the input torque, and periodically detects the rack resistance of the rack in each travel section, adapts to the transmission characteristics of the gear rack steering transmission system, and accurately grasps the transmission resistance that affects the rack output force. When the current input torque is received, the driving force of the input shaft is kept unchanged, so that the input feel fed back to the driver remains unchanged, and the driving force of the power-assisting mechanism is adjusted according to the functional relationship of the corresponding period and the rack resistance of the corresponding period and travel section, so as to achieve the output of the transmission system while supporting the unchanged driving force of the input shaft, so that the steering action of the vehicle matches the steering intention of the driver. The present invention can effectively solve the problem that the change of transmission resistance caused by the mechanical aging of components and changes in the environment in which the vehicle is located affects the driver's feel, can improve driving comfort, and ensure the safety and reliability of the transmission system.

[0038] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the specification are used to explain the principles of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0040] Figure 1 A schematic diagram showing the steps of the transmission output compensation method in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram showing the steps of obtaining the functional relationship between the rack output force and the input torque in an embodiment of the present invention;

[0042] Figure 3 A schematic diagram showing the structure of a strain acquisition circuit in an embodiment of the present invention is shown;

[0043] Figure 4 A schematic diagram showing the steps of obtaining the rack resistance of the rack in each travel section in an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of a module of a transmission output compensation device according to an embodiment of the present invention is shown;

[0045] Figure 6 A schematic structural diagram of an electronic device in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0046] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments described herein. Instead, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art.

[0047] The accompanying drawings are only schematic illustrations of the present invention and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0048] The processes shown in the accompanying drawings are only exemplary and do not necessarily include all the steps. For example, some steps can be decomposed, some steps can be combined or partially combined, and the actual execution order may change according to the actual situation. The words "first", "second" and similar words used in the specific description do not indicate any order, quantity or importance, but are only used to distinguish different components. The term "plurality" means two or more, unless otherwise clearly and specifically defined. In addition, in the description of the present invention, when it is said that a device is "connected" to another device, this includes not only the case of direct connection, but also the case of indirect connection through other elements.

[0049] It should be noted that, in the absence of conflict, the embodiments of the present invention and features in different embodiments may be combined with each other.

[0050] The transmission output compensation method provided in the embodiment of the present invention is applied to a transmission system including a rack and pinion steering gear, wherein the gear is connected to an input shaft and is connected to a power assist mechanism. Figure 1 The main steps of the transmission output compensation method are shown in Figure 2. Figure 1 As shown, the transmission output compensation method provided by the embodiment of the present invention includes:

[0051] S110, obtaining a functional relationship between the rack output force and the input torque and the rack stroke, wherein the rack stroke and the rack output force change with the change of the input torque. S120, obtaining the rack resistance of the rack in each stroke segment. The functional relationship and the rack resistance are updated periodically.

[0052] By periodically obtaining the functional relationship between the rack output force and the input torque and the rack stroke, the change in the relationship between the rack output force and the input torque caused by the change in transmission resistance is studied, so as to overcome the problem of different rack output forces caused by the same input torque due to mechanical aging of components; among them, in the gear rack steering transmission system, the difference and change of rack resistance in different stroke sections are particularly obvious, so by periodically obtaining the rack resistance of the rack in each stroke section, the change of rack resistance with stroke and use is mastered.

[0053] In this way, by periodically updating the functional relationship between the rack output force and the input torque, and periodically detecting the rack resistance of the rack in each travel section, the transmission characteristics of the rack-and-pinion steering transmission system can be adapted, and the transmission resistance that affects the rack output force can be accurately grasped. Among them, the update period of the rack resistance can be smaller than the update period of the functional relationship to match the characteristics that the transmission resistance between the components of the rack-and-pinion steering transmission system changes slowly as a whole, while the rack resistance changes most significantly.

[0054] S130, in response to the current input torque, the driving force of the input shaft is kept unchanged, the current rack stroke and the current rack output force are determined according to the current input torque and the functional relationship, the current rack resistance is determined according to the current rack stroke, and the driving force of the power assist mechanism is determined according to the current rack output force, the current rack resistance and the driving force of the input shaft.

[0055] When the current input torque is received, the driving force of the input shaft is kept unchanged, so that the input feel fed back to the driver remains unchanged, and the driving force of the power-assisting mechanism is adjusted according to the functional relationship of the corresponding cycle and the rack resistance of the corresponding cycle and stroke segment, so as to compensate for the output of the transmission system while supporting the driving force of the input shaft to make the vehicle's steering action match the driver's steering intention.

[0056] Therefore, the transmission output compensation method of the present invention effectively solves the problem that changes in transmission resistance caused by mechanical aging of components and changes in the vehicle's environment affect the driver's feel, can improve driving comfort, and ensure the safety and reliability of the transmission system.

[0057] Figure 2 The main steps to obtain the functional relationship between the rack output force and the input torque are shown in Figure 1. Figure 1 and Figure 2 As shown, in some embodiments, obtaining the functional relationship between the rack output force and the input torque and the rack travel includes:

[0058] When the transmission system is at an update node of the functional relationship: S210, in response to a clockwise input torque manually applied to the input shaft, the clockwise data including the clockwise input torque and the corresponding rack stroke and rack output force are collected, and the functional relationship in the clockwise state is fitted according to the clockwise data; S220, in response to a counterclockwise input torque manually applied to the input shaft, the counterclockwise data including the counterclockwise input torque and the corresponding rack stroke and rack output force are collected, and the functional relationship in the counterclockwise state is fitted according to the counterclockwise data; S230, the functional relationship with the most comfortable hand feel between the functional relationship in the clockwise state and the functional relationship in the counterclockwise state is selected as the functional relationship within the corresponding period.

[0059] In the rack and pinion steering transmission system, there are different degrees of friction between mechanical parts, resulting in different friction forces to overcome when rotating clockwise and counterclockwise under the same input torque, resulting in a certain degree of difference in rack output force. Each time the functional relationship of the transmission system is updated, the input torque is applied to the input shaft by turning the steering wheel. The functional relationship between the rack output force in the clockwise state and the counterclockwise state and the input torque and rack stroke is fitted respectively, and the functional relationship with comfortable feel is selected from them. This effectively solves the problem of unbalanced input torque required for clockwise and counterclockwise steering due to mechanical wear, so that the driver can feel the same when applying input torque clockwise and counterclockwise during vehicle driving.

[0060] Among them, the function fitting is realized by the existing data fitting / curve fitting method. Assume that the clockwise input torque is T CW , the corresponding rack travel is S CW , the corresponding rack output force is F CW , the clockwise data includes enough (T CW ,S CW ,F CW ) data set, so that the fitted function relationship F under the clockwise state CW =F CW (T CW ,S CW ) accurately reflects the rack travel S when driving clockwise CW And rack output force F CW With clockwise input torque T CW The process of change. Assume that the counterclockwise input torque is T CCW , the corresponding rack travel is S CCW , the corresponding rack output force is F CCW , the counterclockwise data includes enough (T CCW ,S CCW ,F CCW ) data set, so that the fitted function relationship F under the counterclockwise state CCW =F CCW (T CCW ,S CCW ) accurately reflects the rack travel S when driving counterclockwise CCW And rack output force F CCW With counterclockwise input torque T CCW The process of change.

[0061] In some embodiments, clockwise data including clockwise input torque and corresponding rack stroke and rack output force are collected, including: collecting a group of clockwise data including continuous clockwise input torque and corresponding rack stroke and rack output force; repeatedly collecting multiple groups of clockwise data; wherein, if there is a rack output force corresponding to the clockwise input torque in each group of collected clockwise data that differs by more than a set threshold, then each group of collected clockwise data is discarded and the clockwise data is collected again.

[0062] The steering wheel can be rotated continuously clockwise, for example, more than two turns clockwise, to collect a set of clockwise data including continuous clockwise input torque and corresponding rack travel and rack output force; when the collected sets of clockwise data fluctuate greatly, the collected data are discarded and re-collected to avoid affecting the accuracy of the functional relationship in the clockwise state. Among them, the difference greater than the set threshold can be a difference greater than the set value or a difference greater than the set ratio. For example, if there is a rack output force corresponding to a clockwise input torque in each set of collected clockwise data that differs by 10%, or by any ratio of 5% to 30%, it can be considered that the collected sets of clockwise data fluctuate too much, but it is not limited to this. When multiple sets of clockwise data (for example, three sets, but not limited to this) that meet the conditions are collected continuously, the functional relationship in the clockwise state can be obtained by fitting.

[0063] Similarly, collecting counterclockwise data including counterclockwise input torque and corresponding rack travel and rack output force includes: collecting a set of counterclockwise data including continuous counterclockwise input torque and corresponding rack travel and rack output force; repeatedly collecting multiple sets of counterclockwise data; wherein, if there is a rack output force corresponding to a counterclockwise input torque in each set of collected counterclockwise data that differs by more than a set threshold, then discarding each set of collected counterclockwise data and re-collecting counterclockwise data. In this way, when each set of collected counterclockwise data fluctuates greatly, discarding the collected data and re-collecting it can avoid affecting the accuracy of the obtained functional relationship in the counterclockwise state. When multiple sets of counterclockwise data that meet the conditions are continuously collected, the functional relationship in the counterclockwise state can be obtained by fitting.

[0064] In some embodiments, during the process of collecting clockwise data and counterclockwise data, the vehicle is kept in a parked state, and the rack moves through the clockwise travel segment and the counterclockwise travel segment respectively.

[0065] Update the functional relationship in the parking state to ensure that the driver feels comfortable when turning the steering wheel while the vehicle is driving. Make the rack move through the clockwise and counterclockwise travel segments respectively to ensure that the obtained functional relationship covers the full travel of the rack, that is, covers various steering scenarios during vehicle driving.

[0066] In some embodiments, in response to the current input torque, the driving force of the input shaft is maintained at the initial driving force; wherein the driving force of the input shaft corresponding to the functional relationship of hand comfort collected when the transmission system is installed on the vehicle and started for the first time is used as the initial driving force.

[0067] When the steering wheel is turned, the input torque, the driving force of the input shaft, and the rack travel can be acquired through the corresponding sensors / controllers of the transmission system. The driving force of the input shaft corresponding to the comfortable hand-feel function acquired when the transmission system is installed on the vehicle and started for the first time is used as the initial driving force of the input shaft to ensure that the input feel of the input torque applied during the subsequent driving of the vehicle remains unchanged at the initial comfortable feel.

[0068] The first update of the function relationship can be achieved during vehicle testing, that is, when the transmission system is installed in the vehicle and started for the first time; the update cycle of the function relationship can be preset in the controller of the transmission system. After the vehicle is delivered, at each update node, the user only needs to turn the steering wheel so that the vehicle collects clockwise and counterclockwise data that meet the update requirements of the function relationship. The vehicle can automatically learn to update the function relationship without user adjustment.

[0069] In some embodiments, the functional relationship is periodically updated based on the mileage of the vehicle; in each cycle of the functional relationship, the rack resistance of the rack in each travel segment is periodically updated.

[0070] As the vehicle's mileage increases, the functional relationship between the rack output force and the input torque is periodically updated to overcome the problem of different rack output forces caused by the same input torque due to mechanical aging of the transmission components. The update period of the functional relationship can be a fixed period, for example, it is updated every L mileage and used as the functional relationship in the subsequent L mileage; the update period of the functional relationship can also be an irregular period, for example, as the mileage increases, the update period of the functional relationship can be gradually reduced. Compared with the overall slow change of the transmission resistance of the rack and pinion steering transmission system, the resistance difference and change of the rack in different travel sections are more obvious. Therefore, in each cycle of the functional relationship, the rack resistance of the rack in each travel section is periodically updated. For example, in one cycle of the functional relationship (such as mileage L), the rack resistance of the rack in each travel segment is updated 4 times, that is, it is updated at the mileage nodes of L / 4 mileage, L / 2 mileage, 3L / 4 mileage, and L mileage, respectively. The rack resistance of each travel segment updated at the L / 4 mileage node is used in the mileage segment of L / 4~L / 2, and the rack resistance of each travel segment updated at the L mileage node is used in the mileage segment of 0~L / 4 of the next cycle of the functional relationship. In the first 0~L / 4 mileage segment of the vehicle, since the rack as a whole has almost no wear and aging problems, it can be considered that the rack resistance of the rack in each travel segment maintains the initial mechanical resistance (the initial mechanical resistance of the rack can be obtained during the acquisition process of the first functional relationship of the transmission system) unchanged.

[0071] In some embodiments, the rack output force is collected by a strain collection circuit. Figure 3 The structure of the strain acquisition circuit is shown in Figure 2. Figure 3 As shown, the strain acquisition circuit includes:

[0072] The strain gauge sensor SGS (Strain Gauge Sensor) is arranged on the rack; the feedback circuit includes an operational amplifier U, two input ends of the operational amplifier U are respectively connected to two ends of the strain gauge sensor SGS, and the output end OUT of the operational amplifier U outputs the rack output force.

[0073] The rack output force of the transmission system is collected through the strain collection circuit so as to adjust the functional relationship between the rack output force and the input torque as needed. Among them, the feedback circuit can be a negative feedback circuit, but is not limited to this. Take the negative feedback circuit as an example: the negative input terminal RF1 and the positive input terminal RF2 of the operational amplifier U are respectively connected to the two ends of the strain gauge sensor SGS through the first current limiting resistor R1 and the second current limiting resistor R3. The strain gauge sensor SGS is installed on the rack and powered by the power supply VCC; the output terminal OUT of the operational amplifier U is connected to the controller of the transmission system, and the output terminal OUT is connected to the negative input terminal RF1 of the operational amplifier U through the feedback resistor R2, and the positive input terminal RF2 of the operational amplifier U is also grounded through the voltage divider resistor R4.

[0074] When the rack output force changes, the potential difference between the two ends of the strain gauge sensor SGS changes accordingly. Assume that the voltages at the two ends of the strain gauge sensor SGS are U RF1 and U RF2 The potential difference between the two ends is U F , the output voltage of the operational amplifier U is U OUT According to the principle of virtual open and virtual short of operational amplifier, we can get the equation: (U OUT -U RF1 )÷(R1+R2)×R1+U RF1 =U RF2 ×R4÷(R3+R4), where R1=R2=R3=R4. Solving the equation yields: U RF1 -U RF2 =U OUT =U F Thus, the controller monitors the output voltage U of the operational amplifier U. OUT , the change of rack output force can be obtained.

[0075] Figure 4 The main steps of obtaining the rack resistance of the rack in each travel section are shown in figure. Figure 1 and Figure 4 As shown, in some embodiments, obtaining the rack resistance of the rack in each stroke segment includes:

[0076] When the transmission system is at the update node of the rack resistance: S410, drive the rack to move to the end position of a stroke segment, wherein each stroke segment is formed by dividing the full stroke of the rack; S420, drive the input shaft clockwise and counterclockwise respectively, and collect a set of resistance values ​​of the reciprocating motion of the rack at the end position; S430, obtain the average of multiple resistance values ​​as the rack resistance of the rack in the stroke segment within the corresponding period.

[0077] According to the movement characteristics of the rack, such as the number of steering wheel rotations, the full stroke of the rack can be divided into multiple travel segments. When the rack resistance is updated, the rack is reciprocated at the end position of each travel segment to detect the rack resistance of the rack in each travel segment. For example, in a specific example, the full stroke S of the rack can be divided into 4 travel segments: 0~S / 4, S / 4~S / 2, S / 2~3S / 4, 3S / 4~S, and the end positions of the 4 travel segments are S / 4, S / 2, 3S / 4, and S respectively. Among them, the rack resistance can be obtained by collecting corresponding sensors. The process of obtaining the rack resistance of the rack in the 0~S / 4 travel segment may include: driving the rack to move to the S / 4 position, turning the steering wheel clockwise and counterclockwise for multiple times (for example, turning the steering wheel clockwise and counterclockwise three times, but not limited to this), collecting multiple resistance values ​​of the rack under clockwise drive and multiple resistance values ​​under counterclockwise drive to form a group of resistance values; then averaging the collected group of resistance values ​​as the rack resistance of the rack in the 0~S / 4 travel segment in the cycle starting from the update node. The update process of other travel segments and other cycles is similar.

[0078] In some embodiments, during the process of collecting a set of resistance values ​​for the reciprocating motion of the rack at the end position: if the collected resistance value during clockwise drive differs from the resistance value during counterclockwise drive by more than a predetermined value, the collected resistance value is discarded and the resistance value is collected again; if among multiple sets of resistance values ​​collected consecutively, the resistance value during clockwise drive and the resistance value during counterclockwise drive of each set differ from each other by more than a predetermined value, the average of the multiple sets of resistance values ​​is taken as the rack resistance of the rack in the stroke segment within the corresponding period.

[0079] When the resistance value collected during clockwise driving fluctuates greatly with the resistance value collected during counterclockwise driving (for example, the resistance value collected during clockwise driving differs from the resistance value collected during counterclockwise driving by more than 10%, but not limited to this), the collected data is discarded and recollected to avoid abnormal fluctuations in forward and reverse rotation caused by non-rack transmission resistance affecting the accuracy of rack resistance. If, in multiple groups of resistance values ​​collected for multiple consecutive times (for example, twice in a row, but not limited to this), each group has a situation where the resistance value collected during clockwise driving differs from the resistance value collected during counterclockwise driving by more than a predetermined value, the possibility of abnormal fluctuations in forward and reverse rotation caused by non-rack transmission resistance can be ruled out, and the average of the multiple groups of resistance values ​​is taken as the rack resistance of the rack in the stroke section in the corresponding period.

[0080] In some embodiments, if the hand feeling of the driving rack moves to a stroke segment suddenly changes, the rack resistance of the rack in the stroke segment in the corresponding cycle is recovered.

[0081] In a certain travel section of the rack, if the driver's hand-felt input torque significantly increases or decreases, it is necessary to re-collect the rack resistance of the travel section to ensure that the rack resistance of the rack in the travel section within the corresponding cycle is accurate.

[0082] In some embodiments, determining the driving force of the power assist mechanism includes: M =F C +f-F I , where F M To assist the driving force of the organization, F C is the current rack output force, f is the current rack resistance, F I is the driving force of the input shaft.

[0083] In order to ensure that the input torque input feel remains consistent during the vehicle's driving process, the driving force F of the input shaft I Keep the initial driving force unchanged; according to the functional relationship between the current input torque and the corresponding cycle, the current rack output force F can be determined C and the current rack travel, and then determine the current rack resistance f according to the rack resistance of the rack in each travel segment in the corresponding cycle and the travel segment that the current rack travel falls into. Then, the driving force F that the assist mechanism needs to provide under the current input torque can be determined. M , to achieve the driving force F on the supporting input shaft I While the rack output of the compensation transmission system remains unchanged, the current rack output force F C It can drive the vehicle's steering action to match the driver's steering intention.

[0084] An embodiment of the present invention further provides an electric power steering system, which uses the transmission output compensation method described in any of the above embodiments to determine the power output of the power motor.

[0085] The electric power steering system of the present invention is specifically a gear rack type electric power steering system, wherein the power mechanism is a motor power mechanism, and the driving force of the power mechanism is the driving force of the power motor. The electric power steering system of the present invention adopts the above-mentioned transmission output compensation method, by periodically updating the functional relationship between the rack output force and the input torque, and periodically detecting the rack resistance of the rack in each stroke segment, accurately grasping the transmission resistance affecting the rack output force, so as to achieve that during the vehicle driving process, the driving force of the input shaft is kept unchanged so that the input feel fed back to the driver remains unchanged, and the driving force of the power mechanism is adjusted according to the functional relationship of the corresponding period and the rack resistance of the corresponding period and stroke segment, so as to achieve that while supporting the driving force of the input shaft unchanged, the output of the transmission system is compensated, so that the steering action of the vehicle matches the steering intention of the driver. Therefore, the electric power steering system of the present invention can effectively solve the problem that the change of transmission resistance caused by the mechanical aging of components and the changes in the environment of the vehicle affects the driver's feel, can improve driving comfort, and ensure the safety and reliability of the electric power steering system.

[0086] The embodiment of the present invention further provides a transmission output compensation device, which is applied to a transmission system including a rack and pinion steering gear, wherein the gear is connected to the input shaft and is connected to a power-assisting mechanism, and the transmission output compensation device can be used to implement the transmission output compensation method described in any of the above embodiments. The features and principles of the transmission output compensation method described in any of the above embodiments can be applied to the following transmission output compensation device embodiments.

[0087] Figure 5 The main modules of the transmission output compensation device are shown in Figure 1. Figure 5 As shown, the transmission output compensation device 500 provided in the embodiment of the present invention includes:

[0088] The function relationship learning module 510 is used to obtain the function relationship between the rack output force and the input torque and the rack stroke, wherein the rack stroke and the rack output force change with the change of the input torque; the rack resistance detection module 520 is used to obtain the rack resistance of the rack in each stroke segment; wherein the function relationship and the rack resistance are periodically updated respectively; the power assist output compensation module 530 is used to respond to the current input torque, keep the driving force of the input shaft unchanged, determine the current rack stroke and the current rack output force according to the current input torque and the function relationship, at least determine the current rack resistance according to the current rack stroke, and determine the driving force of the power assist mechanism according to the current rack output force, the current rack resistance and the driving force of the input shaft.

[0089] Furthermore, the transmission output compensation device 500 may also include modules for implementing other process steps of the above-mentioned transmission output compensation method embodiments. The specific principles of each module can refer to the description of the above-mentioned transmission output compensation method embodiments, and will not be repeated here.

[0090] The transmission output compensation device 500 of the present invention can be integrated into the controller of the transmission system or be communicatively connected to the controller of the transmission system. It is used to solve the problem that changes in transmission resistance caused by mechanical aging of components and changes in the vehicle environment affect the driver's feel. It can improve driving comfort and ensure the safety and reliability of the transmission system.

[0091] An embodiment of the present invention further provides an electronic device, including a processor and a memory, wherein executable instructions are stored in the memory, and when the executable instructions are executed by the processor, the transmission output compensation method described in any of the above embodiments is implemented.

[0092] The electronic device of the present invention can be integrated into the controller of the transmission system or be communicatively connected with the controller of the transmission system, and is used to solve the problem that changes in transmission resistance caused by mechanical aging of components and changes in the vehicle environment affect the driver's feel, thereby improving driving comfort and ensuring the safety and reliability of the transmission system.

[0093] Figure 6 The main structure of the electronic device in the embodiment of the present invention is shown in FIG. Figure 6 As shown, the electronic device 600 is in the form of a general computing device. The components of the electronic device 600 include but are not limited to: at least one processor 610, at least one memory 620, and a bus 630 connecting different platform components (including the memory 620 and the processor 610).

[0094] The memory 620 stores program codes, and the program codes can be executed by the processor 610, so that the processor 610 executes the steps of the transmission output compensation method described in any of the above embodiments.

[0095] The memory 620 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) and / or a cache memory, and may further include a read-only memory unit (ROM). The memory 620 may also include a program / utility having one or more program modules, such program modules including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include the implementation of a network environment.

[0096] Bus 630 may represent one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0097] The electronic device 600 can also communicate with one or more external devices, and the external device can be one or more of the devices such as keyboard, pointing device, Bluetooth device, etc. These external devices enable the user to communicate interactively with the electronic device 600. The electronic device 600 can also communicate with one or more other computing devices, and the computer device shown includes a router and a modem. This communication can be carried out through an input / output (I / O) interface. In addition, the electronic device 600 can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN) and / or a public network, such as the Internet) through a network adapter. The network adapter can communicate with other modules of the electronic device 600 through a bus 630. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, etc.

[0098] An embodiment of the present invention further provides a computer-readable storage medium for storing a program, and when the program is executed, the transmission output compensation method described in any of the above embodiments is implemented.

[0099] The storage medium of the present invention can be integrated into the controller of the transmission system or be communicatively connected to the controller of the transmission system, and is used to solve the problem that changes in transmission resistance caused by mechanical aging of components and changes in the vehicle's environment affect the driver's feel, thereby improving driving comfort and ensuring the safety and reliability of the transmission system.

[0100] The storage medium may be a portable compact disk read-only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a vehicle-mounted computer. However, the storage medium of the present invention is not limited thereto, and may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0101] The storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. The readable signal medium can include a data signal propagated in a baseband or as a part of a carrier wave, wherein a readable program code is carried. This propagated data signal can take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable signal medium can also be any readable medium other than a readable storage medium, which can send, propagate, or transmit a program used by an instruction execution system, device, or device or used in combination with it. The program code contained in the readable signal medium can be transmitted with any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above.

[0102] Program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device, such as through the Internet using an Internet service provider.

[0103] An embodiment of the present invention further provides a computer program product, including a computer program. When the computer program is executed by a processor, the transmission output compensation method described in any of the above embodiments is implemented.

[0104] The computer program product of the present invention can be integrated into the controller of the transmission system or communicated with the controller of the transmission system to solve the problem of changes in transmission resistance caused by mechanical aging of components and changes in the vehicle environment affecting the driver's feel, thereby improving driving comfort and ensuring the safety and reliability of the transmission system.

[0105] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A transmission output compensation method, applied to a transmission system including a rack and pinion steering gear, wherein the gear is connected to an input shaft and is connected to a power assist mechanism, characterized in that: The transmission output compensation method comprises: Obtaining a functional relationship between the rack output force and the input torque and the rack stroke, wherein the rack stroke and the rack output force change with the change of the input torque; Obtain the rack resistance of the rack in each travel section; Wherein, the functional relationship and the rack resistance are updated periodically respectively; In response to the current input torque, the driving force of the input shaft is kept unchanged; the current rack stroke and the current rack output force are determined according to the functional relationship between the current input torque and the current cycle, the current rack resistance is determined according to the current rack stroke, and the driving force of the power-assisting mechanism is determined according to the current rack output force, the current rack resistance and the driving force of the input shaft; Wherein, determining the driving force of the assisting mechanism includes: F M =F C +f-F I , F M is the driving force of the assist mechanism, F C is the current rack output force, f is the current rack resistance, F I is the driving force of the input shaft.

2. The transmission output compensation method according to claim 1, characterized in that: The step of obtaining the functional relationship between the rack output force, the input torque and the rack travel includes: When the transmission system is at the update node of the functional relationship: In response to a clockwise input torque manually applied to the input shaft, collecting clockwise data including the clockwise input torque and the corresponding rack travel and rack output force, and fitting a functional relationship in a clockwise state according to the clockwise data; In response to a counterclockwise input torque manually applied to the input shaft, collecting counterclockwise data including the counterclockwise input torque and the corresponding rack travel and rack output force, and fitting a functional relationship in a counterclockwise state according to the counterclockwise data; The functional relationship with comfortable hand feeling between the functional relationship in the clockwise state and the functional relationship in the counterclockwise state is selected as the functional relationship in the corresponding period.

3. The transmission output compensation method according to claim 2, characterized in that: The acquisition includes clockwise data of the clockwise input torque and the corresponding rack travel and rack output force, including: Collect a set of clockwise data including continuous clockwise input torque and corresponding rack travel and rack output force; Repeatedly collect multiple sets of clockwise data; If, among the collected clockwise data sets, there is a rack output force corresponding to a clockwise input torque whose difference is greater than a set threshold, the collected clockwise data sets are discarded and the clockwise data are collected again.

4. The transmission output compensation method according to claim 2, characterized in that: During the process of collecting the clockwise data and the counterclockwise data, the vehicle is kept in a parking state, and the rack is moved through the clockwise travel segment and the counterclockwise travel segment respectively.

5. The transmission output compensation method according to claim 2, characterized in that: In response to the current input torque, maintaining the driving force of the input shaft at the initial driving force; The driving force of the input shaft corresponding to the functional relationship of hand comfort collected when the transmission system is installed in the vehicle and started for the first time is used as the initial driving force.

6. The transmission output compensation method according to claim 1, characterized in that: The rack output force is collected by a strain collection circuit, and the strain collection circuit includes: A strain gauge sensor is arranged on the rack; The feedback circuit comprises an operational amplifier, wherein two input ends of the operational amplifier are respectively connected to two ends of the strain gauge sensor, and an output end of the operational amplifier outputs the rack output force.

7. The transmission output compensation method according to claim 1, characterized in that: The step of obtaining the rack resistance of the rack in each travel section includes: When the transmission system is at the update node of the rack resistance: Driving the rack to move to the end position of a travel segment, wherein each travel segment is formed by dividing the full travel of the rack; Driving the input shaft clockwise and counterclockwise respectively, collecting a set of resistance values ​​of the reciprocating motion of the rack at the end position; An average value of the group of resistance values ​​is obtained as the rack resistance of the rack in the stroke section in the corresponding cycle.

8. The transmission output compensation method according to claim 7, characterized in that: In the process of collecting a set of resistance values ​​of the reciprocating motion of the rack at the end position: If the resistance value collected during clockwise driving differs from the resistance value collected during counterclockwise driving by more than a predetermined value, the collected resistance value is discarded and the resistance value is collected again; If, among multiple sets of resistance values ​​collected continuously for multiple times, the resistance value of each set during clockwise drive differs from the resistance value during counterclockwise drive by more than a predetermined value, the average of the multiple sets of resistance values ​​is taken as the rack resistance of the rack in the stroke segment during the corresponding period.

9. The transmission output compensation method according to claim 7, characterized in that: If the hand feeling of driving the rack to move to a stroke section suddenly changes, the rack resistance of the rack in the stroke section within the corresponding cycle is recovered.

10. The transmission output compensation method according to any one of claims 1 to 9, characterized in that: The functional relationship is periodically updated based on the vehicle's mileage; In each cycle of the functional relationship, the rack resistance of the rack in each stroke segment is periodically updated.

11. An electric power steering system, characterized in that: The electric power steering system adopts the transmission output compensation method as described in any one of claims 1 to 10 to determine the power output of the power motor.

12. A transmission output compensation device, applied to a transmission system including a rack and pinion steering gear, wherein the gear is connected to the input shaft and is connected to a power assist mechanism, characterized in that: The transmission output compensation device is used to implement the transmission output compensation method according to any one of claims 1 to 10, comprising: A functional relationship learning module, used to obtain a functional relationship between a rack output force and an input torque and a rack stroke, wherein the rack stroke and the rack output force change with a change in the input torque; A rack resistance detection module is used to obtain the rack resistance of the rack in each travel section; Wherein, the functional relationship and the rack resistance are updated periodically respectively; a power output compensation module, for keeping the driving force of the input shaft unchanged in response to the current input torque; determining the current rack stroke and the current rack output force according to the functional relationship between the current input torque and the current cycle, determining the current rack resistance according to the current rack stroke, and determining the driving force of the power assist mechanism according to the current rack output force, the current rack resistance and the driving force of the input shaft; Wherein, determining the driving force of the assisting mechanism includes: F M =F C +f-F I , F M is the driving force of the assist mechanism, F C is the current rack output force, f is the current rack resistance, F I is the driving force of the input shaft.

13. An electronic device, characterized in that: include: processor; A memory, wherein executable instructions are stored in the memory; Wherein, when the executable instruction is executed by the processor, the transmission output compensation method as described in any one of claims 1-10 is implemented.

14. A computer-readable storage medium for storing a program, characterized in that: When the program is executed by a processor, the transmission output compensation method as described in any one of claims 1 to 10 is implemented.

15. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the transmission output compensation method according to any one of claims 1 to 10 is implemented.

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