CN116142298A

CN116142298A - Steering power-assisted compensation method and device

Info

Publication number: CN116142298A
Application number: CN202211473328.6A
Authority: CN
Inventors: 张琰; 武金波; 周鹏; 陈乾忙; 朱雨彤
Original assignee: Dongfeng Motor Group Co Ltd
Current assignee: Dongfeng Motor Group Co Ltd
Priority date: 2022-11-21
Filing date: 2022-11-21
Publication date: 2023-05-23

Abstract

The invention discloses a steering power-assisted compensation method and a device, wherein the steering power-assisted compensation method is characterized in that whether a vehicle runs on a straight track or not is determined through target parameters comprising at least a steering angle and a running speed by acquiring the steering torque and the target parameters of the vehicle, when the vehicle runs on the straight track and the steering torque is larger than a preset torque threshold value, the steering torque is uneven when a steering wheel of the vehicle is in a neutral position, a compensation torque is generated, the steering torque is compensated based on the compensation torque, the steering torque is reduced to the target value, the steering wheel is effectively restrained from having different left and right light hand feeling due to mechanical errors, and the steering wheel is caught by abnormal torque, so that the driving safety when the vehicle runs straight is improved.

Description

Steering power-assisted compensation method and device

Technical Field

The application relates to the technical field of power-assisted steering compensation, in particular to a power-assisted steering compensation method and device.

Background

Existing vehicles mostly employ an electric power steering system (ESP, electric Power Steering) that includes a steering mechanism, a torque/angle sensor, a controller, and a motor drive mechanism, the steering mechanism being a mechanical mechanism connected via a steering wheel and a steering shaft. When steering, a driver manipulates a steering wheel to apply torque, so that a mechanical torsion bar connected with a steering shaft is deformed, a torque/angle sensor detects angular offset and generates an initial torque signal, the current driver manipulation intention is determined and output to a controller, and therefore, the power-assisted torque output of a motor driving mechanism is determined through a motor control unit in the controller, and the driver is assisted in steering operation.

When the steering wheel is centered, the vehicle is traveling straight, the torque/angle sensor is placed in absolute neutral, and the controller then has no associated torque signal input, and does not provide a power-assisted torque to the steering mechanism. To achieve the above objective, the steering system needs to be initialized and calibrated in the middle position, but the sensor structure commonly adopted in the present stage is a non-contact hall sensor, the middle position torque signal is calibrated as an extremum method, the input shaft is driven by fixing the torque output end of the steering system, the mechanical torsion bar is mechanically deformed, the signal identification of the torque/angle sensor is correspondingly changed, and when the torsion bar is deformed to reach a certain amount, the voltage value of the torque signal output controller reaches the maximum, namely the extremum of the torque signal. Then, the average value calculation is performed through the left limit value and the right limit value so as to calibrate the neutral position of the initializing machine. In the mechanical neutral position, the default steering system of the sensor is not deformed, and the output torque voltage signal is zero. However, due to mechanical tolerance of the whole vehicle, the steering wheel may need to be rotated to a specific angle slightly deviated from the middle position of the steering wheel for a long time when the vehicle is in straight running, and a driver always needs to provide a small torque to keep the vehicle in straight running, so that the steering force feeling is uneven when the vehicle is in straight running, or the running of the vehicle in straight running is deviated, and the like, so that potential safety hazards exist when the vehicle is in straight running.

Therefore, how to improve the driving safety when the vehicle is traveling straight is a technical problem to be solved at present.

Disclosure of Invention

The steering power-assisted compensation method and the device improve the driving safety when the vehicle runs straight.

The embodiment of the invention provides the following scheme:

in a first aspect, an embodiment of the present invention provides a steering assist compensation method, including:

acquiring steering torque and target parameters of a vehicle, wherein the target parameters at least comprise a steering angle and a running vehicle speed;

determining whether the vehicle runs in a straight track according to the target parameters;

when the vehicle runs in a straight track, determining whether the steering torque is greater than a preset torque threshold;

when the steering torque is greater than the torque threshold, generating a compensation torque and performing compensation processing on the steering torque based on the compensation torque so as to reduce the steering torque to a target value.

In an alternative embodiment, determining that the vehicle is traveling in a straight track according to the target parameter includes:

and when the steering angle is in a preset range and the running speed is greater than a preset speed, determining that the vehicle runs in a straight track.

In an alternative embodiment, before determining whether the vehicle is traveling in a straight track according to the target parameter, the method further includes:

judging whether the vehicle executes a preset task based on any one value of the steering torque, the steering angle and the running vehicle speed;

if so, outputting a cancel compensation signal to cancel the compensation processing of the steering torque in the current period.

In an alternative embodiment, the generating a compensation torque and compensating the steering torque based on the compensation torque includes:

receiving a torque signal indicative of the steering torque;

obtaining a first compensation value according to an integral processing result of the torque signal in a first preset period;

obtaining a second compensation value according to an average value of a plurality of first compensation values in a second preset period, wherein the set duration of the second preset period is longer than that of the first preset period;

determining the second compensation value as the compensation torque when the compensation deviation is not greater than a first threshold value, wherein the compensation deviation is a difference value between the second compensation value and the first compensation value;

and outputting a compensation signal according to the compensation torque, wherein the compensation signal is used for reducing the steering torque to a target value.

receiving a correlation signal of a vehicle, wherein the correlation signal is a signal representing the steering torque, the steering angle, the running vehicle speed and a vehicle fault;

obtaining a plurality of period compensation values according to integration processing results of the target signal in the associated signal in different preset periods;

and determining a target compensation value in the plurality of periodic compensation values as the compensation moment, and outputting a corresponding compensation signal.

In an alternative embodiment, said determining a target compensation value of said plurality of period compensation values as said compensation torque comprises:

obtaining an angle corresponding relation according to each period compensation value and the corresponding angle range;

and determining a target compensation value in the plurality of periodic compensation values according to the corresponding relation between the steering angle and the angle, and determining the target compensation value as the compensation moment.

Obtaining a weight corresponding relation according to each period compensation value and the corresponding period weight;

and obtaining a calculated compensation value according to the corresponding relation between the plurality of periodic compensation values and the weights, and determining the calculated compensation value as the compensation moment.

In an alternative embodiment, the plurality of period compensation values include a short-term compensation value and a long-term compensation value, and after obtaining the plurality of period compensation values according to integration processing results of the target signal in the associated signal in different preset periods, the method further includes:

receiving a compensation configuration instruction of the vehicle;

and determining the short-term compensation value and/or the long-term compensation value as compensation torque based on the compensation configuration instruction, and outputting a corresponding compensation signal.

In an alternative embodiment, after the receiving the association signal of the vehicle, the method further comprises:

outputting a target signal of the associated signal to a corresponding processing terminal for integral processing according to the signal frequency of the associated signal to obtain a plurality of frequency compensation values;

and determining at least one compensation value in the plurality of frequency compensation values as the compensation moment and outputting a corresponding compensation signal.

In a second aspect, an embodiment of the present invention further provides a steering assist compensation device, including:

the system comprises an acquisition module, a control module and a control module, wherein the acquisition module is used for acquiring steering torque and target parameters of a vehicle, and the target parameters at least comprise steering angle and running speed;

the first determining module is used for determining whether the vehicle runs in a straight track or not according to the target parameters;

the second determining module is used for determining whether the steering torque is larger than a preset torque threshold value or not when the vehicle runs in a straight track;

and the processing module is used for generating a compensation torque and carrying out compensation processing on the steering torque based on the compensation torque when the steering torque is larger than the torque threshold value so as to reduce the steering torque to a target value.

Compared with the prior art, the steering power-assisted compensation method and device have the following advantages:

according to the steering power-assisted compensation method, whether the vehicle runs in a straight track or not is determined through the target parameters comprising at least the steering angle and the running speed of the vehicle, when the vehicle runs in the straight track and the steering torque is larger than the preset torque threshold, the fact that the steering wheel of the vehicle has uneven steering force feel when in the middle position is indicated, the compensation torque is generated, the steering torque is compensated based on the compensation torque, the steering torque is reduced to the target value, the steering wheel is effectively restrained from having different left and right light weight handfeel due to mechanical errors, and the steering wheel is caught by the abnormal torque, so that the driving safety of the vehicle in the straight running process is improved.

Drawings

In order to more clearly illustrate the embodiments of the present description or the technical solutions in the prior art, the drawings that are required for the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present description, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a method for compensating steering assist according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a steering system according to an embodiment of the present invention;

FIG. 3-1 is a logic diagram I of a first embodiment of a method for compensating steering assist according to an embodiment of the present invention;

fig. 3-2 is a logic diagram two of a first embodiment of a steering assist compensation method according to an embodiment of the present invention;

fig. 3-3 are a logic diagram three of a first embodiment of a steering assist compensation method according to an embodiment of the present invention;

fig. 4 is a logic diagram of a second embodiment of a steering assist compensation method according to the present invention;

fig. 5 is a schematic structural diagram of a steering compensator according to an embodiment of the present invention;

FIG. 6-1 is a logic diagram I of a third embodiment of a steering assist compensation method according to an embodiment of the present invention;

FIG. 6-2 is a logic diagram II of a third embodiment of a steering assist compensation method according to an embodiment of the present invention;

FIG. 7 is a logic diagram of a fourth embodiment of a steering assist compensation method according to an embodiment of the present invention;

FIG. 8-1 is a logic diagram I of a fifth embodiment of a method for compensating for steering assist in accordance with an embodiment of the present invention;

fig. 8-2 is a logic diagram two of a fifth embodiment of a steering assist compensation method according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the relationship between voltage and torque signals provided by an embodiment of the present invention;

FIG. 10 is a schematic diagram of noise processing of a torque signal according to an embodiment of the present invention;

fig. 11 is a signal flow schematic diagram of a sixth embodiment of a steering assist compensation method according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a steering assist compensation device according to an embodiment of the present invention.

Reference numerals illustrate: 1-steering wheel, 2-upper rotating shaft, 3-universal joint, 4-lower rotating shaft, 5-steering gear, 6-rack shaft, 7-outer pull rod, 8-steering joint and 9-wheel assembly;

10-controller, 11-helping hand motor, 12-motor position sensor, 13-angle position sensor, 14-steering torque sensor, 15-worm wheel, 16-worm, 17-vehicle power.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments, and all other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the embodiments of the present invention.

Referring to fig. 1, fig. 1 is a schematic diagram of a power-assisted steering compensation method according to an embodiment of the present invention, where the method includes:

s11, acquiring steering torque and target parameters of the vehicle, wherein the target parameters at least comprise a steering angle and a running vehicle speed.

Specifically, the steering torque, steering angle, and running vehicle speed may be measured by sensors mounted on the vehicle. Referring to fig. 2, in the steering system, an upper shaft 2 is mounted on a steering wheel 1, and the upper shaft 2 is connected to a lower shaft 4 through a universal joint 3 to transmit torque to a steering gear 5. When the driver turns the steering wheel 1, torque is transmitted to the upper rotating shaft 2, the steering gear 5 drives the rack shaft 6 to move linearly, and the rack shaft 6 is connected to the outer tie rod 7 (only one side of the vehicle is shown in the drawing), thereby moving the knuckle 8 and driving the wheel assembly 9 to steer.

The assist torque of the steering system may be provided by an assist system, with continued reference to fig. 2, including a controller 10, an assist motor 11, a motor position sensor 12, an angular position sensor 13, and a steering torque sensor 14. The controller 10 is powered by a vehicle power supply 17, a worm wheel 15 is arranged on the upper rotating shaft 2, and the worm wheel 15 is in driving connection with the power-assisted motor 11 through a worm 16. The motor position sensor 12 is used for measuring the rotor position of the booster motor 10 and outputting to the controller 10; the controller 10 may also receive an input signal from an external bus that may be integrated to provide a vehicle travel estimate signal, such as yaw rate, lateral acceleration, or other vehicle motion signals known in the art, from which the travel speed may be obtained.

The angular position sensor 13 may be an optical code type sensor, a variable resistance type sensor, or any other suitable type of position sensor for performing an angular position detection function. The angular position sensor 13 is used to detect the rotation angle of the steering wheel 1, and although the steering angle of the steering wheel 1 measured by the angular position sensor 13 is mentioned herein, any equivalent combination of signals may be used to determine the steering angle of the vehicle within the scope of the disclosure. Devices such as a motor position sensor, a steering column position sensor SAS, a rack position sensor, and combinations thereof may be used instead of the angle position sensor 13.

When the steering wheel 1 rotates, the steering torque sensor 14 senses the torque applied to the steering wheel 1 by the vehicle driver. The steering torque sensor 14 may include a torsion bar hall sensor and a variable resistance type sensor, and outputs a change in torque associated with mechanical torsion bar deformation, that is, a steering torque, to the controller 10.

In response to the input signals from the sensors, the controller provides steering torque assistance to the steering system in addition to any steering force applied by the vehicle operator by sending command signals to the assist motor 11, for which command signals the assist motor 11 provides assistance torque to the steering system via the worm 16 and worm gear 115. The steering torque and the target parameter of the vehicle are acquired to step S12.

And S12, determining whether the vehicle runs in a straight track according to the target parameters.

Specifically, the vehicle traveling in a straight track is a steering wheel steady control direction, and the vehicle is kept in a straight traveling state. The determination may be made by the steering angle and the running vehicle speed, for example, when the steering angle of the vehicle is at a fixed angle and the running vehicle speed is not zero, it may be determined that the vehicle is running in a straight track.

In practical implementation, in the process of straight running, due to external factors such as road surface jolts, if the limitation condition on straight running is too severe, the accuracy of determining straight track running may be insufficient. Based on this, in a specific embodiment, when the steering angle of the vehicle is in the preset range and the traveling speed is greater than the preset speed, it may be determined that the vehicle travels in a straight track.

Specifically, when the vehicle is traveling in a straight line, the steering wheel needs to be kept within a preset range; and the vehicle needs to maintain a certain running speed, so that the vehicle can be determined to be in a straight running state, namely, to run in a straight track. The steering angle and the running speed may be determined based on the experience of the skilled person, or may be determined by calibration tests. The preset range may be determined by filtering the steering signal representing the steering angle, for example, in the case of a low steering torque and a high vehicle speed. The steering signal is monitored and slowly filtered, and the filtered result can accurately screen the steering wheel angle range allowed by the center of the steering wheel. It can be understood that when the steering torque is lower than the first set value and the vehicle speed is higher than the second set value, the vehicle is in a driving scene of a high-speed road condition or a better road condition, and generally runs in a straight track, so that the preset range can be determined according to the change range of the steering angle in a set duration. By setting the preset range and the preset speed, the accuracy of determining the straight track running of the vehicle is improved.

In practical application, since the steering assistance compensation of the vehicle needs to be performed under straight running, the vehicle may perform a preset task during straight running, resulting in abnormality of the target parameter. Based on this, in a specific embodiment, before determining whether the vehicle is traveling in a straight track according to the target parameter, the method further includes:

judging whether the vehicle executes a preset task based on any value of steering torque, steering angle and running speed; if so, outputting a cancel compensation signal to cancel the compensation processing of the steering torque in the current period.

Specifically, if any value of the steering torque, the steering angle and the running vehicle speed is executing a preset task, if the data is not truly represented, a cancel compensation signal is output, the task cycle is exited, and the compensation processing of the steering torque is not executed.

Referring to fig. 3-1 and 3-2, step S301 monitors at least one set of torque signal, angle signal, vehicle speed signal applied to the steering wheel; in step S302, a steering wheel angle range is defined based on the monitoring of the steering wheel angle position, which range estimates the correspondence between the steering wheel angle and the vehicle traveling in a substantially linear manner, where the steering wheel angle range is not absolutely centered at zero degrees. The zero angle position is defined as an angular position value in which the steering wheel does not substantially rotate left or right; step S303, judging whether the current steering wheel angle position is within a preset range; if yes, go to step S304 to confirm the authenticity of at least one of the following items: (a) a steering torque applied to the steering wheel, (b) a steering wheel angular position, (c) a vehicle speed, using at least one of (1) vehicle state information, (2) whether the detected torque, steering wheel angular position and/or vehicle allowable limit speed are within a limit definition range; step S305, (a) applied torque monitored on the steering wheel, (B) an angular position signal monitored on the steering wheel (C) a monitored vehicle speed signal. Any one of the above is in an invalid state under the judgment of the limit value test; if yes, go to step S301; if not, go to step S306, according to monitoring at least one of the following: steering torque, steering angle and running speed; determining whether the vehicle is traveling along a nearly straight travel path; it is determined that the vehicle is traveling in a straight trajectory, and the process advances to step S13.

And S13, when the vehicle runs in a straight track, determining whether the steering torque is larger than a preset torque threshold value.

Specifically, the moment threshold may be determined according to actual requirements, for example, an abnormal moment value perceived by a driver when the vehicle is traveling straight is taken as a highest value of the moment threshold. With continued reference to fig. 3-2, in step S308, the torque sensor monitors the torque on the steering wheel by a torque sensing signal responsive to the applied torque, i.e. obtains a steering torque, and when the steering torque is greater than a torque threshold, it indicates that the steering torque has an influence on the driver, and the process proceeds to step S14.

And S14, when the steering torque is larger than the torque threshold value, generating a compensation torque and carrying out compensation treatment on the steering torque based on the compensation torque so as to reduce the steering torque to a target value.

Specifically, the compensation torque may be a set value, or may be calculated and determined based on a correlation signal of the vehicle, and the compensation processing may be performed on the steering torque, so as to reduce the steering torque to a target value that cannot be perceived by a driver, so as to inhibit the steering system from having different hand feeling of the steering wheel due to mechanical error.

Referring to fig. 5, during driving of the vehicle, steering assist is achieved by the EPS algorithm 50, and the steering torque perceived by the driver is determined by the torque assist function 56 and the sum function 54. The torque of the rack shaft represents the actual torque of the vehicle steering, and is usually larger due to the friction force between wheels and the ground, so that the driver is inconvenient to operate the steering, the power-assisted torque is calculated through the torque power-assisted function 56, and the power-assisted torque is output to the sum function 54 for power-assisted steering. The compensation method described in the embodiment of the present invention may be integrated into a steering compensator 52, and step S309 is implemented: the input torque signal is filtered by a low pass filter comprising a dielectric time constant. The associated signal of the vehicle is received at the condition determination module 62 to determine whether the vehicle is traveling in a substantially linear direction, and the associated signal may be passed at the filter 60 as a condition determination basis to filter the torque signal applied by the driver. If the condition determination module 62 outputs a TRUE value (TRUE) signal, that may characterize the vehicle as traveling along a substantially linear straight-direction path, and then filter the torque signal. If the condition determination module 62 outputs a FALSE value signal (FALSE), the output value of the filter 60 will retain its previous signal value without refreshing. The signal is then output to an integrator 70, the function of the integrator 70 being to integrate the filtered value towards zero under the condition of a calibrated gain. Integrator 70 may be considered a constant quantizer, a proportional increment, or any other form of increment that meets design criteria. At the same time, a calibration value may be preceded and if the measured torque is below a certain threshold, no delta and compensation is applied. If the condition determination module 62 produces a FALSE value signal (FALSE) output, the input to the integrator 70 is set to zero. Thus, while self-learning does not occur, the previous learning compensation signal is still applicable. The limit determination function 76 uses a calibration function to determine whether the compensation torque exceeds a desired or preset value. The algorithm continues to reduce the steering drag force felt by the steering wheel until the steering torque reaches a target value, which may be zero or below a calibrated preset threshold.

It should be noted that the compensation torque can be implemented in several alternative ways, for example by continuous compensation performed in real time, or by adding one or more calculated compensation torques at the start of each ignition cycle, and furthermore by compensating at the start of the ignition cycle after detecting the presence of drag forces (i.e. steering torque greater than the torque threshold) in a plurality of ignition cycles, and adding them to the configuration word, to take account of the storage and selection of a plurality of values, or by writing offsets to memory locations, during vehicle service, the person with access rights performs the compensation operation. Each ignition cycle includes the vehicle activating an ignition mechanism to start the vehicle, driving the vehicle, and then turning off the vehicle, powering down.

The steering compensator 52 receives the steering wheel torque signal as one of its inputs and generates a compensation torque signal that is added to the conventional steering assist command system. Thus, when there is steering drag on the vehicle system, the controller 10 will eventually reduce the steering torque to a level that is imperceptible to the driver. The compensation process first determines that a residual assistance torque is present at the steering wheel due to traction. When the controller 10 determines that there is a high likelihood of a poor residual torque in the steering wheel torque and the driver is planning to travel forward along a substantially linear straight path, the EPS algorithm controller 50 outputs the compensation torque calculated by the steering compensator 52 to the function calculation unit 58 without providing torque to control the steering wheel during straight travel, so that in the exemplary embodiment the driver may take his hands off the steering wheel and the vehicle may continue to travel along a substantially straight path without further driver intervention, the compensation torque calculated by the steering compensator 52 may be stored in a preset storage location in the ECU memory 74 that may be reset when the vehicle is being taken off line or when vehicle service is being performed to correct steering assist.

In a specific embodiment, generating a compensation torque and compensating the steering torque based on the compensation torque includes:

receiving a torque signal indicative of steering torque; obtaining a first compensation value according to an integral processing result of the torque signal in a first preset period; obtaining a second compensation value according to an average value of a plurality of first compensation values in a second preset period, wherein the set duration of the second preset period is longer than that of the first preset period; when the compensation deviation is not greater than the first threshold value, determining the second compensation value as a compensation moment, wherein the compensation deviation is a difference value between the second compensation value and the first compensation value; and outputting a compensation signal according to the compensation torque, wherein the compensation signal is used for reducing the steering torque to a target value.

Specifically, referring to fig. 3-3, the first compensation value may be shown in step S310: the first integrator is used for carrying out product on a torque signal after low-pass filtering, so that a steering drag force compensation required value estimated in a short period, namely a first compensation value, is generated; step S311, modifying the acquired torque signal by a second low-pass filter with a second time constant greater than the first time constant; step S312, the modified signal from the second low-pass filter is integrated by a second integrator, so as to obtain a predicted value of the steering drag compensation of a long period, namely a second compensation value; step S313, combining the short period predicted value and the long period predicted value, thereby generating a tension compensation signal and outputting the tension compensation signal to the booster motor. It will be appreciated that there are various embodiments in which the first compensation value and the second compensation value are combined to generate the compensation signal, in one example, when the compensation deviation is not greater than the first threshold value, which means that the first compensation value does not fluctuate significantly compared to the second compensation value, and the vehicle is in a stable straight running state, the second compensation value is determined as the compensation torque, and the corresponding compensation signal is output to reduce the steering torque to the target value.

When the steering torque compensation is actually performed, the steering torque may have a certain amplitude of fluctuation, and if the steering torque is compensated by only adopting a fixed value, the compensation amount may be excessively large, and the problem of uneven hand feeling of the steering wheel caused by light weight and heavy weight is also caused. Based on this, in a specific embodiment, generating a compensation torque and compensating the steering torque based on the compensation torque includes:

receiving a correlation signal of a vehicle, wherein the correlation signal is a signal representing steering torque, steering angle, running speed and vehicle fault; obtaining a plurality of period compensation values according to integration processing results of target signals in the associated signals in different preset periods; and determining a target compensation value in the plurality of period compensation values as a compensation moment, and outputting a corresponding compensation signal.

Specifically, the target signal may be all signals representing steering torque, steering angle, running speed and vehicle failure; part signals, such as torque signals that characterize the steering torque, are also possible. The number of the preset periods can be determined according to actual requirements, for example, two or three; the integration processing results of different preset periods represent different orders of the period compensation values, the target compensation value in the period compensation values represents the required magnitude of the compensation torque, the determination can be based on the steering angle, the determination can be also performed in other modes, and the target compensation value can compensate the steering torque to the target value.

Referring to fig. 4, step S401 obtains one or more sensor signals on the vehicle, which may include one or more of a torque signal, an angle signal, and a vehicle speed signal of the steering wheel; step S402, judging whether the vehicle runs along a nearly straight path when running; if yes, go to step S403 to measure the steering wheel torque signal and judge the magnitude of the steering drag force on the steering wheel; step S404, calculating a steering power-assisted compensation moment for reducing the steering drag force to be close to zero through a function, namely determining a target compensation value; in step S405, the calculated steering assist compensation torque is applied to the steering system, i.e., a corresponding compensation signal is output.

Referring to fig. 6-1, the associated signals may be obtained from various sensor inputs, and the steering wheel angle signals may be measured by the steering wheel angle sensors and may be translated into steering wheel angular positions, which in an embodiment may be proportional values derived from the relationship between the motor position sensors and the steering wheel angular position sensors. The angular position refers to the rotation position of the steering wheel, represents the direction in which the vehicle is turned, and a plurality of period compensation values can be obtained after the integration processing of the correlation signals. It will be appreciated that the speed of the vehicle is determined by a vehicle speed signal and a vehicle fault signal, for example, in some vehicle models, the vehicle speed signal is determined by a wheel speed sensor or an onboard ECU or both, and then output to a communication bus, and other signals indicative of vehicle movement may be obtained by signal lines, such as steering wheel speed, vehicle acceleration, yaw rate, lateral acceleration, wheel speed, etc. The vehicle fault signal (or vehicle status signal) may be implemented using any device or combination of devices capable of detecting one or more operational faults or diagnostic conditions of the vehicle. For example, the vehicle status is implemented using an onboard computing device that meets the vehicle Diagnostic (OBD-II, on-Board Diagnostics) standard, and is capable of outputting one or more detected fault codes (DTCs) upon detection of a fault condition.

In the following, it will be explained in detail how the period compensation value is obtained by the target signal, and with continued reference to fig. 6-1, the torque signal is transmitted as an electrical signal to the summer as a first input value, and is also input to the input of the first conditional low-pass filter, and the output value of the summer is transmitted as an input to the second conditional low-pass filter. The first conditional low-pass filter is activated by combining the long-period logic judgment device with the first timer, the second conditional low-pass filter is activated by combining the short-period logic judgment device with the second timer, the output value of the first conditional low-pass filter is processed by the first limiter, and the output of the second conditional low-pass filter is processed by the second limiter; the first timer and the second timer are used for setting an integration period. The first stop and the second stop allow only signals having signal values within a set range to pass, or signals having signal values below a predetermined threshold, or both. The selection of the stop is set based on the magnitude of the drag force compensation that is desired to be achieved, or the initial response time that is desired to be achieved. Similarly, the first and second stops cannot transmit signals that do not fall within the range of signal values, or cannot transmit signals that are below a predetermined threshold, characterizing the angular range of the steering wheel. When the period compensation value is obtained through torque signal integration, the torque signal represents analog quantity, the signal value is subjected to integration processing, and after the signal value is processed through a second conditional low-pass filter, when the angle range set by a second limiter is reached, a compensation signal is output to enter and exit the compensation processing. It should be noted that, the summer, the filter, the timer, the limiter, and the like may all implement corresponding functions based on a software manner, or may also build an analog circuit based on electronic components to obtain corresponding functions.

In a specific embodiment, determining a target compensation value of the plurality of periodic compensation values as the compensation torque includes:

obtaining an angle corresponding relation according to the compensation value of each period and the corresponding angle range; and determining a target compensation value in the plurality of period compensation values according to the corresponding relation between the steering angle and the angle, and determining the target compensation value as the compensation moment.

Specifically, referring to fig. 6-2, the output value of the first limiter is transferred to the first integrator, the output of the second limiter is transferred to the second integrator, and both the first integrator and the second integrator may support initializing the pre-parameter value to a zero value or a stored value. In an exemplary embodiment, the leading parameter value of the first integrator is initialized to a zero value at vehicle ignition power-up or other reset operation, and the leading parameter value in the second integrator is initialized to a stored value at vehicle ignition power-up or other reset operation. The loop comprising the first conditional low pass filter and the first integrator is defined as a set of short-period loops. The loop comprising the second conditional low pass filter and the second integrator is defined as a set of long-period loops. The short-period path runs continuously in the time domain. In an exemplary embodiment. The operation of the short-period working circuit is independent of the independent closed loop of the long-period circuit. Thus, short term compensation may be enabled before long period compensation is initiated. The sensed torque signal is low pass filtered when the vehicle is determined to be traveling along a substantially linear straight forward path based on one or more vehicle sensors. The use of the first conditional low pass filter in the short-term path provides a relatively fast time constant, which in one example embodiment is about 0.035Hz. If the vehicle alignment parameter condition is met, it is indicative that the vehicle is traveling along an alignment path determined by one or more vehicle sensors operatively coupled to the short-term enabling logic, and the sensed torque signal is filtered accordingly. Based on the first integrator and the second integrator, different period compensation values can be obtained, the compensation amounts represented by the different period compensation values are different, accordingly, an angle corresponding relation can be built with different angle ranges, a target compensation value is determined according to the angle range in which the steering angle is located, and the target compensation value is determined to be a compensation moment.

If the condition for straight ahead travel of the vehicle is not met, the output of the first conditional low pass filter, also known as "short term bias", maintains its previous history. The short-term deviation is fed back to the first integrator. If the condition for straight running of the vehicle is satisfied, the short-term deviation integral is evaluated. Otherwise, the input value of the first integrator is set to zero, while the output of the first integrator remains unchanged. If steering behavior, such as a change in vehicle heading, is identified, the first integrator state variable may also be reset or jumped to zero to avoid changing the direction of travel of the vehicle due to external factors in windy weather or the vehicle traversing a section of arching. When the vehicle is powered on and off by controlling ignition of the vehicle through the ignition switch, the output result of the first integrator is not stored. The deviation here also includes a predefined minimum torque value of the steering wheel based on a systematic torque residual error present in the steering wheel. If the identified short-term torque deviation is less than the minimum value of the steering wheel torque, the short-term deviation is not integrated by the first integrator. This allows the specified steering tension compensation to be only below some predetermined minimum tension level, such as 0.25Nm. Compensation further below this minimum level is not desirable, as the readings obtained by the steering wheel sensor may be subject to errors, or simply to avoid continuously tracking the last few error counts. In an exemplary embodiment, the minimum steering wheel torque is set to zero.

obtaining a weight corresponding relation according to each period compensation value and the corresponding period weight; and obtaining a calculated compensation value according to the corresponding relation between the plurality of periodic compensation values and the weights, and determining the calculated compensation value as a compensation moment.

Specifically, each period compensation value corresponds to the integration processing result of different periods, and the longer the period setting time is, the smaller the fluctuation amplitude of the represented period compensation value is; on the contrary, the shorter the period setting time is, the period compensation value required to be output in a shorter time can be represented. In order to ensure better accuracy of the compensation moment determination, a weight corresponding relation can be established according to the method, and the calculated compensation value is obtained through corresponding weights in the corresponding relation between the plurality of period compensation values and the weights according to the weight corresponding relation established by the different period compensation values corresponding to different weights. For example, in a scenario with two period compensation values, the formula can be:

T ₁ w ₁ +T ₂ w ₂ calculation of the calculated compensation value K, T ₁ For the first period compensation value, w ₁ Is short-term anti-integral saturation value (or first weight value), T ₂ For the second period compensation value, w ₂ For long-term anti-integral saturation value (or called second weight value), the integral processing time length corresponding to the first period compensation value can be 30s, and the integral processing time length corresponding to the second period compensation value can be 30min, w ₁ And w ₂ The value of (2) can be configured according to the actual requirement.

In particular, with continued reference to fig. 6-2, the first integrator may set a short-term anti-integral saturation value and the second integrator may set a long-term anti-integral saturation value, the output of the first integrator being input to the first weighting booster to achieve the desired response time, along with the time constant of the previously selected first conditional low pass filter. For example, it takes 25 seconds to realize short-term bias learning of about 1n.m with a gain of 0.54 and a setting parameter of a sampling time of 0.002 seconds. It should be noted that while the disclosed first and second integrators are used in the embodiments, other techniques may be used, such as constant increments, increments proportional to short term deviation, variable integral gain, or the like. As previously described, the integration process of the target signal over different preset periods may set a long-term path including the control loop of the second conditional low-pass filter and the second integrator, and a short-term path that may be cyclically operated over a continuous time or across a plurality of ignition periods. The ignition cycle is defined as starting the vehicle by an ignition switch, driving the vehicle, and turning off the vehicle by placing the ignition switch in an off position. Regardless of whether the long-term path is running continuously or across multiple ignition cycles, the long-term path is not reset during the driving process, and the output result of the second integrator is stored when the vehicle is stopped. This stored value is only re-zeroed (i.e., using serial messages on the vehicle communication bus) if the vehicle is undergoing maintenance to repair the steering drag problem. If a time domain continuous approach is used, it is similar to the short-term path, but has a longer filter time constant (e.g., cutoff frequency of about 0.001 Hz) and a smaller integrator gain (e.g., 0.0015) for the second conditional low-pass filter, and in the illustrated embodiment a sampling time of about 0.064 seconds. The above parameter values can realize long-term deviation learning compensation of 1n.m within 15 minutes.

In practice, short-term path modifications are performed quickly to determine whether the drag bias is due to road surface heave, gusts, or vehicle chassis parameters. This is relatively advantageous because the driver does not have to wait a long period to complete the steering drag problem due to the chassis problem. Ideally, if the drag problem is normalized (caused by a long term phenomenon), this drag compensation should migrate from the short term path to the long term path. The long-term path will then initialize to this value in the next firing cycle without having to relearn corrections. In this way, a true, long-term chassis compensation self-learning is optimized over time, rather than cycling repeatedly through each firing cycle. This is desirable because a truly long-term repair compensation occurs in each ignition cycle. On the other hand, short term effects of rough roads and crosswinds are corrected. The correction of the sudden temporary situation should be relearned for every ignition cycle, and possibly after detection of a steering event (e.g. steering the vehicle 90 degrees).

If the short-term path has been compensated for steering drag, the torque sensor of the steering wheel has failed to sense a corresponding torque signal for the long-term path to correct. The approach to this is to effectively remove the short-term contribution from the input to the long-term path before the signal is sent to the second conditional low-pass filter. By scaling the gain, the short term correction value is scaled down to the appropriate input torque unit and is applied as a second input to the summer before the second conditional low pass filter, superimposed on the actual measured steering wheel torque. Any limitations due to calibration or vehicle speed should be accounted for by the added value in order to properly remove the current effects of the short term correction. As described above, the long-term path may be more robust to perform, allowing for updates in multiple firing cycles.

As described above, the first integrator may include a short term anti-saturation limit and the second integrator may include a long term anti-saturation limit. The anti-saturation limit may prevent the output of the first integrator and the second integrator from becoming too large over time, as there may be a persistent error in the input of the integrators. For diagnostic purposes, this anti-saturation limit may be set to a steering drag force compensation value that is higher than the allowable range. If the learned correction offset value is much greater than allowed, the vehicle malfunction service lamp may be lit, for example, when the vehicle is serviced. In another embodiment, the anti-saturation limit value may be set to not exceed the compensation values for short-term and long-term path potential. The output of the integrator is not allowed to exceed the required correction range. One of the benefits of this arrangement is that the correction compensation must be cancelled due to the change in driving conditions, avoiding a long waiting time for the integrator to drop to the actual correction level. If the diagnosis needs to be limited, it can be calculated independently and compared with the correction value itself.

In some systems, an automotive manufacturer may wish to limit the maximum allowable drag force compensation to no more than a predetermined value, such as 1n.m. This can avoid serious vehicle problems that are covered by the steering compensation and that require maintenance. If this limit is high enough (e.g., 3 n.m), it is not considered a critical safety consideration for the overall steering command performed by the assist motor. If it is desired to limit the overall compensation to within 1n.m, the long-term path may also be limited to 1n.m. If drag is a long term phenomenon, this will allow the full compensation to be stored mobile to a long term path. The short-term path may also be limited to 1n.m, or possibly up to 2n.m. Limiting the long-term and short-term paths to the same value allows only maximum correction on either path. If there is a greater limit on the short-term path, the vehicle can obtain an output correction of 1n.m even without these temporary conditions.

If the long-term path and the short-term path are each constrained to output a smaller period compensation value, it is possible that the output of the first integrator in the short-term path will be greater than its current gain. For example, each path is limited to 1n.m and the overall correction is limited to 1n.m. The short-term path output has a period compensation value of 0.75n.m and the long-term path output has a period compensation value of 0.75n.m. The sum is 1.5n.m, but since the overall correction value of this sum is limited to 1n.m, its final value is 1n.m. The driving conditions may change and require a correction to reduce the short-term path (i.e. the road surface is flatter and the direction of travel of the vehicle is not changed) so that the short-term correction is moved from 0.75n.m to 0n.m and reduced to a suitable output value, since the upper output limit has been limited to 1n.m, and the process has no direct effect on the calculated compensation value of the overall output.

In the previous example, the short term correction must drop below 0.25n.m before the driver of the vehicle can feel the effect of the correction. Thus, in this example, the ability of the short-term path to quickly evaluate and cope with road condition changes is not effectively utilized. Although the time required to reduce the short-term path output to 0.25n.m is not long, this is an unnecessary wait. By identifying that the actual output of the short-term path is not 0.75n.m, but at 0.25n.m (total correction minus long-term correction), the short-term anti-saturation limit may be reduced to a lower value (e.g., 0.25 n.m), thereby reducing or eliminating the time period required under temporary driving conditions. Thus, if the integrated output of the short-term path is below the weighted calculation value, the weighted calculation value will advantageously decrease to a level comparable to the actual integrated output.

The anti-integral saturation values corresponding to the different period compensation values may also be determined based on the speed range of the vehicle, which would be very useful if the relationship between the drag force condition and a given vehicle speed could be determined. This mixture with the vehicle speed may be output by summing with an adder. Alternatively, the coupling of the vehicle speed may be performed independently on the short-term path and the long-term path, respectively, so as to effectively acquire the output of the short-term path, thereby calculating the appropriate input of the long-term path as described above.

With continued reference to fig. 6-2, if diagnostics are required, the calculated compensation value output by the summer may also be compared to a preset compensation limit. If the calculated compensation value exceeds the preset compensation limit value, a fault lamp or an engine maintenance lamp of the vehicle is lighted, or the calculated compensation value is gradually reduced to zero according to a preset gradient, or the output compensation torque is kept at a historical value. Either of the above conditions ultimately alerts the driver to the vehicle being serviced. Any stored long term value will be reset to zero during vehicle repair service.

In a specific embodiment, the plurality of period compensation values include a short-term compensation value and a long-term compensation value, and after obtaining the plurality of period compensation values according to integration processing results of the target signal in the associated signal in different preset periods, the method further includes:

receiving a compensation configuration instruction of a vehicle; and determining the short-term compensation value and/or the long-term compensation value as compensation moment based on the compensation configuration instruction, and outputting a corresponding compensation signal.

Specifically, the compensation configuration command can be sent out through the control of a driver, after the short-term compensation value is determined to be the compensation torque through the compensation configuration command, a corresponding compensation signal is output for compensation, the short-term compensation value represents the integral processing result of the short-term path, the steering torque of the vehicle caused by factors such as road surface fluctuation or crosswind can be corrected to be larger than a torque threshold, and the short-term compensation value can be stored in a plurality of ignition cycles; if not stored during multiple ignition cycles, there is no need to reset the long-term path correction after vehicle repair. This alternative implementation is a viable option if satisfactory performance is achieved only through short-term paths and the learning time is sufficiently short.

According to another alternative embodiment, the determination of the compensated configuration command to use only the long term compensation value as the compensation torque may be used to correct the steering torque of the vehicle due to the chassis problem being greater than the torque threshold, rather than attempting to correct temporary problems such as rough terrain and crosswind, when the vehicle chassis problem is to be compensated. Such an embodiment may be performed continuously, in real time, may optionally use a time constant of a second conditional low pass filter that is slower than previously described, may optionally be implemented using a second integrator of lower gain than previously described, and optionally long term path compensation may delay or calculate a number of ignition cycles.

According to another alternative embodiment, the compensation torque is driver selectable. The compensation function may be automatically disabled, for example in an ignition state, which may be achieved by a physical switch or a remote lever which, when pressed, provides visual feedback in the form of an indicator light. The driver may enable or disable the entire compensation function, or only enable or disable the correction function of the short-term path or the long-term path. If the driver turns off the entire compensation function, re-enabling the function may result in the learned long-term path being reset to zero or may be set to not be reset, depending on the host plant requirements. If re-enabling would zero the learned long-term path, no special service program is required to reset the long-term path correction via serial messages on the vehicle communication bus. Another is the need to initiate a long-term path modification reset request by the driver, logging a reset that can reset the oil change indicator on the vehicle to perform the long-term path modification.

Of course, the short-term compensation value and the long-term compensation value may be determined as compensation torque based on the compensation configuration command, and after the short-term compensation value is subjected to compensation processing, it is determined whether the steering torque reaches the target value, and when the steering torque does not reach the target value, the long-term compensation value is used for compensation.

In a specific embodiment, after receiving the association signal of the vehicle, the method further comprises:

outputting a target signal of the associated signal to a corresponding processing terminal for integral processing according to the signal frequency of the associated signal to obtain a plurality of frequency compensation values; at least one compensation value of the plurality of frequency compensation values is determined as a compensation torque, and a corresponding compensation signal is output.

Specifically, referring to fig. 7, the processing terminal may include a low-pass filter and an integrator, or may include only the integrator, where the low-pass filter is an electronic filtering device that allows signals below a cutoff frequency to pass, but signals above the cutoff frequency cannot pass. The processing terminal can separate out a perceived torque signal according to frequency elements contained in the signal, and the torque signal is input by a corresponding sensor. The torque signal is input to the input of a slow low pass filter that filters the torque signal. The enabling condition logic circuit configures the operating parameters of the low pass filter and the integrator as the vehicle is determined to be traveling along a substantially linear straight path based on the associated signal, enabling the enabling condition logic circuit to enable processing of the signal by the slow low pass filter, the fast integrator, and the slow integrator.

The slow low pass filter is designed with a sufficient cut-off frequency to separate long term (low frequency) phenomena from the perceived torque signal. The output of the slow low pass filter is representative of the torque of the steering wheel output being active in a lower frequency range, and its signal is extracted to the slow integrator, with the effect of modifying or adjusting the low pass filter output over time. More specifically, any non-zero values in this low frequency range are integrated to calculate a long term corrected period compensation value.

In addition to the low frequency filtered output, the total steering wheel torque is the remainder of the driver applied torque, yet to be checked for correction. The remaining components, when passing through the first summer 71, subtract the output of the slow low pass filter from the sensed torque signal and input to the fast low pass filter. As previously described, if the fast low pass filter is activated by enabling the conditional logic, the fast low pass filter will filter the remaining elements. The cut-off frequency of the fast low-pass filter is selected to be higher than the cut-off frequency of the slow low-pass filter. The cut-off frequency of the fast low-pass filter is selected with reference to the output of a short-term compensation value, such as a transition phase from a straight road to a rough road or a sudden encounter with a crosswind. The output of the fast low pass filter is provided to a slow integrator to further refine the correction.

The fast low pass filter and the fast integrator form a short term path that produces an output in the form of a short term correction. This short term correction is independent of the long term correction produced by the long term path, which includes a slow low pass filter and a slow integrator. The second summer 72 sums the long term correction produced at the slow integrator output with the short term correction produced at the fast integrator output. The output of the second summer represents an overall correction. The above-described determination straight-line running condition, restriction condition, output unit scaling unit, and vehicle speed scaling unit are still applicable. Accordingly, the output of the second summer 72 may be transmitted to a limiter to limit the total value of the correction to a predetermined range or to limit the magnitude of the total correction to below a predetermined threshold.

Referring to fig. 8-1 and 8-2, the associated signals include inputs for one or more signals, such as a torque signal, an angle signal, a vehicle speed signal, and a fault signal for the steering wheel. The first conditional low pass filter is activated by an operative coupling of the first timer and the short-term enable logic. The second conditional low pass filter is activated by an operative coupling of the second timer and the long term enable logic. The output of the first conditional low pass filter is processed by a limiter, and the output of the second conditional low pass filter is processed by a change limiter. The limiter may be by a signal within an allowable signal range, or by a signal below a predetermined threshold, or both. The variation limiter limits the filtered long-term drag force compensation value to the step-size variation effect increment. The step change effect delta may be stored directly in the ECU memory or may be stored incrementally by adding the step change effect delta to a previously stored past value.

The output of the limiter is passed to an integrator, which may include a short term anti-saturation limit. The integrator supports initializing past parameter values to zero values or stored values. In an exemplary embodiment, past value parameters in the integrator are initialized to stored long-term finite calculated values on a reset or other initialization event. The output of the integrator is fed to a weighting gain to achieve the desired corresponding time, and the time constant of the previously selected first conditional low pass filter. It should be noted that when the disclosed embodiments of the present example use an integrator, other techniques may be used, such as constant delta, delta proportional to short term deviation, variable integral gain, or the like. The output of the integrator, which represents the short-term path correction, is scaled to a compensation torque by a weighting gain and output to the assist motor. The weighting gains may weight the respective short-term path corrections with a value from 0 to 1 using a weighting function. Alternatively, the short-term path may be scaled as a function of vehicle speed. A limiter limits the value of the weighting gain output as the tension compensation offset signal.

If the short-term calculation continues for a period of time, the value obtained by passing the short-term calculation through a slow low-pass filter (i.e., a second conditional low-pass filter) may be used as a learned long-term input value. The output of the weighted gain may be passed to a second conditional low pass filter for generating a long term input value. This is not used to directly generate the drag force compensation offset signal, but rather the long term contribution is stored in a non-volatile memory, such as the ECU memory. The long-term input value may be limited to a fixed magnitude during each firing cycle to achieve a robust boost by varying the limiter. This helps to ensure that only the true long term effects are stored with very little compensation, gradually tending towards the ideal value. For a non-robust, more responsive system, the long term impact of one allowable change may be infinite step size. As previously described, the short-term path is initialized to a long-term stored value at the beginning of the next firing period. If a short-term reset is required, it may be reset to a long-term value instead of zero. Thus, the schemes illustrated in FIGS. 7-1 and 7-2 provide the basic functionality in the embodiments, and the schemes illustrated in FIGS. 5-1 and 5-2 are less computationally complex.

FIG. 9 is a graphical representation of voltage as a function of torque for an example of the output of the steering wheel torque sensor shown in FIG. 2. The steering wheel torque sensor generates two voltage outputs, T1 and T2, respectively. When the steering wheel is stationary, the torque is shown along the X-axis as 0n.m, without any applied force. Under this condition, the voltage T1 and the voltage T2 are both substantially equal to 2.5V in absolute value. When the force applied to the steering wheel tries to turn the steering wheel left or right, the steering wheel torque increases, which corresponds to a torque change of 0n.m to-8 n.m, as the force acting on the steering wheel pulls the steering wheel to the left limit. When the torque reaches-8 N.m, the voltage T1 can reach +5V at maximum and the voltage T2 can reach 0V at minimum. On the other hand, when a force is applied to the steering wheel to pull the steering wheel to the right, the voltage T1 is 0V at minimum and the voltage T2 is +5v at maximum. It is to be understood that the specific values of voltage and torque shown in fig. 9 are for illustrative purposes only. The torque signal includes two components, T1 and T2, the sum of T1 and T2 being 5V, regardless of the force applied to the steering wheel. This setting may be used to diagnose a torque sensor of the steering wheel to determine whether the torque signal provided by the torque sensor is unacceptably noisy in the steering effort compensation.

Referring to fig. 10, to achieve a predetermined level of noise in the torque signal, it is possible to determine whether a bias torque is present on the steering wheel by monitoring the sensed torque signal, where the vehicle may be traveling along a substantially straight path. Thus, in some cases it may be desirable to determine whether the sensed torque signal is too noisy, which if present, would result in erroneous bias values being learned and compensated for. The torque sensor provides a sensed torque signal in the form of two voltages T1 and T2, which are added at the output of the third adder 101. The output is input to a low pass filter. The low pass filter is only activated when the sum generated by the third adder 101 is within a predetermined range, such as when a test is activated. This predetermined range is denoted as MinX, maxX, and the low pass filter may be initialized with a nominal or desired value, the output of the low pass filter being limited by the clipping filter. The second summer 102 subtracts a finite value from the output of the first summer 101. The output of the shear filter is the long-term average of the sum of T1 and T2. In practice, both T1 and T2 will have a noise component and if the noise becomes large, the difference between the filtered signal at the output of the shear filter and the output of the first adder 101 will become large. This error term is compared to the acceptable range set in the function activation test. If the difference is within an acceptable range, the sensed torque signal may be used as an effective drag force compensation. If the difference exceeds the acceptable range, then the drag force compensation will be disabled.

FIG. 11 is a system block diagram providing steering tension compensation according to a sixth set of embodiments disclosed herein. The system uses an optional device in the form of an input calibration mechanism to apply a preset compensation value to the booster motor controlled by the processing mechanism. The calibration input mechanism may include any keyboard device, touch screen display, personal computer, microprocessor-based device, or switch. The system of fig. 11 applies steering tension compensation in a passive manner if an optional calibration input mechanism is not used.

The processing module comprises fault and limit judgment and is used for limiting the movement range of the power-assisted motor. The processing mechanism is capable of receiving an input of a vehicle speed signal, an input of a calibration input mechanism, an input of a tension compensation signal generator, and the like. The processing mechanism is programmed to access a calibratable vehicle speed pull scale stored in the memory. The memory device may be external to the processing mechanism, may be integrated into the processing module, or both. In an exemplary embodiment, the storage device may be an ECU memory and the processing module may be included in the controller.

Based on the optional input received by the calibration input mechanism, the processing module accesses the memory device and, based on the input received from the vehicle speed sensor, may retrieve one or more appropriate values from within the calibration vehicle speed pull scale. The retrieved value is multiplied by the output of the tension compensation generator by a multiplier-divider (Σ in the figure) to generate the drive signal of the assist motor. Before the drive signal is applied to the booster motor, the signal is subjected to fault and limit logic. The system of fig. 11 does not require any "self-learning" of steering tension and can be used effectively in situations where it is desirable to eliminate existing steering tension conditions. This may be diagnosed and compensated for during vehicle assembly or maintenance by vehicle assessment or roll alignment. The correction amount may be scaled with vehicle speed, but is not required. Using the calibration input mechanism, the driver may select or specify a desired amount of steering tension compensation, and in some system applications it may be desirable to limit the amount of compensation that may be selected or specified to ensure that the user does not create dangerous driving conditions. For example, the maximum allowable compensation range is limited to 3n.m or less. This will allow the driver to adjust the compensation settings as needed depending on the vehicle loading, driving conditions, and other environmental factors. If the driver finds that the vehicle has a slight but constant drag, the driver can adjust a small amount of correction to avoid vehicle service. If the steering drag force exceeds the program or predefined limit. The driver has to solve this problem by means of a vehicle repair service.

Based on the same inventive concept as the compensation method, the embodiment of the invention further provides a steering assist compensation device, referring to fig. 12, the device includes:

an obtaining module 201, configured to obtain a steering torque and a target parameter of a vehicle, where the target parameter includes at least a steering angle and a running vehicle speed;

a first determining module 202, configured to determine whether the vehicle runs on a straight track according to the target parameter;

a second determining module 203, configured to determine, when the vehicle runs on a straight track, whether the steering torque is greater than a preset torque threshold;

and the processing module 204 is used for generating a compensation torque and carrying out compensation processing on the steering torque based on the compensation torque when the steering torque is larger than the torque threshold value so as to reduce the steering torque to a target value.

In an alternative embodiment, the apparatus further comprises:

the judging module is used for judging whether the vehicle executes a preset task based on any value of the steering moment, the steering angle and the running vehicle speed;

and the output module is used for outputting a cancel compensation signal when the vehicle executes a preset task based on any one value of the steering torque, the steering angle and the running vehicle speed so as to cancel the compensation processing of the steering torque in the current period.

Other device structures and compensation methods related to the steering assist compensation device provided in the embodiment of the present invention are corresponding relations, and are not described herein in detail.

The technical scheme provided by the embodiment of the invention has at least the following technical effects or advantages:

the steering power-assisted compensation method comprises the steps of obtaining steering torque and target parameters of a vehicle, determining whether the vehicle runs on a straight track through the target parameters at least comprising steering angle and running speed, when the vehicle runs on the straight track and the steering torque is larger than a preset torque threshold value, indicating that uneven steering force sense exists when a steering wheel of the vehicle is in the middle position, generating compensation torque, and compensating the steering torque based on the compensation torque, so that the steering torque is reduced to a target value, the steering system is effectively prevented from having different left and right light handfeel of the steering wheel caused by mechanical errors, and the steering wheel is caught by abnormal torque, so that the driving safety of the vehicle in straight running is improved.

It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (modules, systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A steering assist compensation method, the method comprising:

2. The steering assist compensation method according to claim 1, characterized in that determining that the vehicle is traveling in a straight trajectory based on the target parameter comprises:

3. The steering assist compensation method according to claim 1, wherein before determining whether the vehicle is traveling in a straight trajectory based on the target parameter, the method further comprises:

4. The steering assist force compensation method according to claim 1, characterized in that the generating a compensation torque and compensating the steering torque based on the compensation torque, comprises:

receiving a torque signal indicative of the steering torque;

5. The steering assist force compensation method according to claim 1, characterized in that the generating a compensation torque and compensating the steering torque based on the compensation torque, comprises:

6. The steering assist compensation method of claim 5, wherein said determining a target compensation value of the plurality of period compensation values as the compensation torque comprises:

7. The steering assist compensation method of claim 5, wherein said determining a target compensation value of the plurality of period compensation values as the compensation torque comprises:

8. The steering assist compensation method as set forth in claim 5, wherein the plurality of period compensation values include a short-term compensation value and a long-term compensation value, and wherein after obtaining the plurality of period compensation values based on integration processing results of the target signal in the associated signal at different preset periods, the method further comprises:

receiving a compensation configuration instruction of the vehicle;

9. The method of power steering compensation of claim 5 wherein after receiving the vehicle associated signal, the method further comprises:

10. A steering assist compensation device, the device comprising: