CN116461603A - EPS (electric power steering) power assisting mode control method and device, electronic equipment and storage medium - Google Patents

EPS (electric power steering) power assisting mode control method and device, electronic equipment and storage medium Download PDF

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Publication number
CN116461603A
CN116461603A CN202310325147.7A CN202310325147A CN116461603A CN 116461603 A CN116461603 A CN 116461603A CN 202310325147 A CN202310325147 A CN 202310325147A CN 116461603 A CN116461603 A CN 116461603A
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CN
China
Prior art keywords
vehicle speed
lateral acceleration
steering torque
current
determining
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Pending
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CN202310325147.7A
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Chinese (zh)
Inventor
陈磊
赵亚超
郭顺
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Dongfeng Motor Corp
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Dongfeng Motor Corp
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Priority to CN202310325147.7A priority Critical patent/CN116461603A/en
Publication of CN116461603A publication Critical patent/CN116461603A/en
Pending legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0457—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by control features of the drive means as such
    • B62D5/046—Controlling the motor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B62D6/008—Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Abstract

The invention discloses an EPS power-assisted mode control method, a device, electronic equipment and a storage medium, wherein the method comprises the following steps: acquiring the current vehicle speed, lateral acceleration and steering torque of a steering wheel; determining a scaling factor from the vehicle speed and the lateral acceleration; and determining final assistance current according to the first assistance current in the first assistance mode and the second assistance current in the second assistance mode under the vehicle speed and the steering torque condition and the proportionality coefficient. The beneficial effects are that: according to the vehicle speed, the lateral acceleration and the characteristic index steering torque gradient for evaluating the steering stability of the vehicle, the vehicle stability characteristic and the hand feeling feedback force of the driver are judged, so that the proportionality coefficient among different steering power assisting modes is obtained, the force sense of the steering force of the driver is properly corrected, and the flexible and smooth force sense change is ensured.

Description

EPS (electric power steering) power assisting mode control method and device, electronic equipment and storage medium
Technical Field
The invention relates to the technical field of driving control methods, in particular to an EPS (electric power steering) assistance mode control method, an EPS assistance mode control device, electronic equipment and a storage medium.
Background
The steering system is used as a system directly interacted with a driver, the transverse control requirement of the driver is required to be perceived at any time, meanwhile, the state of the vehicle and the road surface is required to be fed back in time, different drivers have different driving styles, and the control force requirement on the steering wheel is different. EPS electric power steering system: the system mainly monitors the moment of a steering wheel operated by a driver, inputs the moment, and controls the current of a motor to output corresponding power-assisted steering torque; the larger the EPS power steering torque, the lighter the force the driver feels to be steering through the system negative feedback to the steering wheel.
The prior art is broadly divided into two types, one is an inherent single assist mode, i.e., EPS provides a single fixed level of assist by steering torque information from a steering torque sensor, where the steering effort of the driver to control the lateral movement of the vehicle is fixed, requiring the driver to adapt to the vehicle. The other is to preset a plurality of boosting modes in the EPS system, wherein the boosting force corresponding to each mode is different, the feedback is fed back to the driver to feel light and heavy, but each mode needs to be independently or coupled and adjusted with the driving mode, and the multi-mode functions need to be activated and exited under a certain vehicle speed steering torque condition.
Different modes of assistance under the same speed of a vehicle, the technical scheme aiming at different hand force demands of drivers is usually realized by calibrating in a multi-mode manner, under different steering modes, the steering force of the drivers is different, under Normal mode, EPS assistance is larger, the drivers feel that the steering force is lighter, under Sport mode, the assistance of an EPS motor is smaller, the drivers are required to have larger steering force, and the steering force style is more stable.
However, in the same fixed steering assist mode, the lateral acceleration and steering torque characteristics of the vehicle under the steady state rotation condition are fixed, and the gradient change of the steering force is different under the condition that the change rate of the lateral acceleration of the vehicle is different. The switching of the two different modes is realized by a switching instruction outside the system, the steering force is two relatively fixed types, and the hand feeling is relatively single.
At low vehicle speeds, the vehicle lateral acceleration is at a small level with a small turning radius, and at this time, the driver wants to have a change in steering torque with respect to a gentle steering wheel, but a certain torque gradient is also reflected, but the change in torque gradient is constant in the single Sport mode or Normal mode. For example, in the Sport mode, the torque gradient is larger, the steering torque of the steering wheel increases more rapidly, and the driver feels heavy, even in this mode, the driver needs to ensure that the steering of the vehicle is stable, the steering force is reduced as much as possible, and the heavy hand feeling in the Sport mode is not maintained.
Similarly, under the working condition of high speed and large turning radius, the lateral acceleration of the vehicle is larger, the assistance force in Normal mode is larger, the steering wheel hand force felt by the driver is smaller, although the steering wheel force is smaller under the condition of ensuring the steering stability of the vehicle, the hand feeling is lighter, the stability of the vehicle under the working condition is more important, and at the moment, the steering wheel moment is controlled by the larger hand force of the driver under the lateral acceleration.
Similarly, when the vehicle moves forwards in a serpentine shape at different steering angles or in an emergency obstacle avoidance process, the vehicle state is switched from low lateral acceleration to high lateral acceleration, the steering torque gradient change of the corresponding steering wheel is certain in the same fixed steering mode, steering comfort cannot be ensured under the condition of small lateral driving degree, and the high lateral acceleration is actively switched and excessive mainly in measurement.
The different power-assisted modes are all based on the selection of a driver, are a passive adjustment mechanism, and the driving hand feeling of the two modes is fixed, when the lateral acceleration starts to increase from zero, the vehicle is indicated to enter a turning state from a straight running state, at the moment, the vehicle has larger lateral acting force in a shorter time, if the steering moment is too small, the driver can easily reach the required steering requirement, but the excessive steering condition is easy to occur due to the portability of the steering force, and the vehicle is dangerous at a higher speed or a specific obstacle avoidance requirement.
Disclosure of Invention
In view of the above drawbacks or improvements of the prior art, an object of the present invention is to provide a method, a device, an electronic apparatus, and a storage medium for controlling an EPS assist mode.
To achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, a control method for an EPS assist mode includes the steps of:
acquiring the current vehicle speed, lateral acceleration and steering torque of a steering wheel;
determining a scaling factor from the vehicle speed and the lateral acceleration;
and determining final assistance current according to the first assistance current in the first assistance mode and the second assistance current in the second assistance mode under the vehicle speed and the steering torque condition and the proportionality coefficient.
In one embodiment, the step of determining the scaling factor from the vehicle speed and the lateral acceleration comprises:
acquiring a first functional relation between lateral acceleration and steering torque gradient under each vehicle speed condition of a first power-assisted mode and a second functional relation between lateral acceleration and steering torque gradient under each vehicle speed condition of a second power-assisted mode;
under the preset vehicle speed condition of a test mode, the real vehicle marks out a test mapping relation between lateral acceleration and steering torque gradient, and the steering torque gradient corresponding to any lateral acceleration in the test mapping relation is between the two corresponding steering torque gradients in the first functional relation and the second functional relation under the same preset vehicle speed and lateral acceleration condition;
and determining a proportionality coefficient according to the first functional relation, the second functional relation and the test mapping relation.
In one embodiment, the step of calibrating the test mapping relationship between the lateral acceleration and the steering torque gradient by the real vehicle under the preset vehicle speed condition of the test mode includes:
and determining a preset vehicle speed condition according to the vehicle speed interval.
In one embodiment, the vehicle speed interval is set according to the magnitude of the vehicle speed difference in different vehicle speed ranges.
In one embodiment, the step of setting the vehicle speed section according to the magnitude of the vehicle speed difference in different vehicle speed ranges includes:
a high vehicle speed range and a low vehicle speed range are preset, the vehicle speed difference during the high vehicle speed range setting vehicle speed being smaller than the vehicle speed difference during the low vehicle speed range setting vehicle speed.
In one embodiment, the step of determining the test pattern comprises:
determining a functional relationship f of the first assist mode steering torque and the EPS-assist current 1 (x) And a second power-assisted mode steering torque and EPS-assisted current function f 2 (x)；
The functional relation g (x) between steering torque and EPS-assisting current in the test mode meets the following conditions:
g(x)＝[f 1 (x)+f 2 (x)]/2。
in one embodiment, the step of determining the scaling factor based on the first functional relationship, the second functional relationship, and the trial mapping relationship comprises:
taking a plurality of lateral accelerations, corresponding to each lateral acceleration, respectively determining the steering torque gradient by the first functional relation and the second functional relation as a lower boundary value and an upper boundary value, and taking the steering torque gradient determined by the test mapping relation as a proportionality coefficient input value;
dividing the difference between the input value of the proportionality coefficient and the lower boundary by the difference between the upper boundary value and the lower boundary value to determine an initial proportionality coefficient corresponding to the lateral acceleration;
and carrying out average value calculation on the initial proportional coefficient corresponding to each lateral acceleration, and determining the initial proportional coefficient as the proportional coefficient.
In one embodiment, the mean calculation is a weighted mean calculation, and each initial scaling factor corresponds to a weighting factor;
the weighting coefficient of the initial scaling factor corresponding to the lateral acceleration smaller than the nominal lateral acceleration is larger than that of the initial scaling factors corresponding to the rest lateral acceleration.
In one embodiment, the step of determining the final assist current based on the first assist current in the first assist mode and the second assist current in the second assist mode under the vehicle speed and the steering torque condition and the scaling factor includes:
and determining final power-assisted current by a convex combination algorithm according to the first power-assisted current calibrated in the first power-assisted mode under the current vehicle speed and the steering torque, the second power-assisted current calibrated in the second power-assisted mode, the first parameter, the second parameter and the proportionality coefficient.
In one embodiment, the determining the scaling factor based on the vehicle speed and the lateral acceleration further comprises the steps of:
and determining that the vehicle speed is in a preset speed interval, and simultaneously, determining that the lateral acceleration is in a preset acceleration interval.
In one embodiment, the step of determining that the vehicle speed is within a preset speed interval and the lateral acceleration is within a preset acceleration interval comprises:
determining that the vehicle speed is above a first preset vehicle speed or below a second preset vehicle speed, wherein the first preset vehicle speed is greater than the second preset vehicle speed;
and determining that the lateral acceleration is smaller than a preset acceleration.
In a second aspect, an EPS assist mode control device includes:
the first module is used for acquiring the current vehicle speed, the lateral acceleration and the steering torque of the steering wheel;
a second module for determining a scaling factor based on the vehicle speed and the lateral acceleration;
and the third module is used for determining a final assistance current according to the first assistance current in the first assistance mode and the second assistance current in the second assistance mode under the condition of the vehicle speed and the steering torque and the proportionality coefficient.
In a third aspect, an electronic device includes a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the EPS assist mode control method as described above when executing the computer program.
In a fourth aspect, a computer-readable storage medium stores computer instructions that cause the computer to perform the steps of the EPS assist mode control method as described above.
The invention has the beneficial effects that: for an EPS power-assisted mode control method, an EPS power-assisted mode control device, electronic equipment and a computer readable storage medium, the current vehicle speed, the lateral acceleration and the steering torque of a steering wheel are obtained; determining a proportionality coefficient according to the vehicle speed and the lateral acceleration; determining final power-assisted current according to a first power-assisted current in a first power-assisted mode and a second power-assisted current in a second power-assisted mode under the conditions of vehicle speed and steering torque and a proportion coefficient, judging vehicle stability characteristics and hand-feel feedback force of a driver according to the vehicle speed, lateral acceleration and a characteristic index steering torque gradient for evaluating vehicle steering stability, further obtaining proportion coefficients among different steering power-assisted modes, finally realizing moderate correction of the force sense of steering operation force of the driver, and ensuring flexible smooth force sense change.
Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.
Drawings
The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic diagram of a conventional EPS construction;
fig. 2 is a flowchart of an EPS assist mode control method provided in the present embodiment;
FIG. 3 shows a graph of lateral acceleration as a function of steering torque gradient;
fig. 4 is a schematic diagram of an EPS assist mode control device according to the present embodiment;
fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.
In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The embodiment provides a control method for an EPS assist mode, which is applied to an automotive EPS, and fig. 1 is a schematic diagram of a common EPS structure, as shown in fig. 1, where the EPS includes a torque sensor, an EPS electronic control unit, a motor, a speed reducer, and the like.
The torque sensor is a sensor for detecting steering torque of a driver, is an important device for detecting basic information required for EPS, and is generally constituted by a torsion bar provided on a steering shaft and a sensor for detecting a torsion angle of the torsion bar.
The torque sensor in this embodiment is a magnetic induction type, and the concave-convex relative positions of the detection coil and the compensation coil, which are specifically installed at the upper and lower positions of the torsion bar, are changed along with the torsion of the torsion bar, and the corresponding magnetic circuit change is obtained through the detection coil arranged at the outer side.
The present embodiment is not limited to the hall integrated circuit type and the dual resolver type torque sensor.
The ESP electronics unit is composed of a microcontroller for control, an integrated circuit for monitoring (sometimes a microcontroller), a drive circuit for the motor (drive circuit and switching circuit), relays for switching on and off the motor path and the power supply path, an interface circuit for receiving external signals, etc. The motor driving circuit is used for PWM control on the on-off of the power element.
The EPS may be classified into three kinds of steering column assist, gear assist, and rack assist depending on the kind and assist position of the motor.
The steering column booster type motor comprises a column shaft and a motor. The gear assisted motor includes a motor and a pinion. The rack-assisted motor is divided into four types, including a rack coaxial-assisted type, a rack cross-assisted type, a rack parallel-assisted type and a double-pinion-assisted type. The rack and the motor in the rack coaxial booster type are coaxially arranged. The racks in the rack cross power assisting type are arranged in a cross mode with the motor. The rack and the motor in the rack shaft parallel boosting type are arranged in parallel along the axial direction. In the double-pinion boosting type motor, two pinions are improved on the basis of an original motor, and the two pinions and the rack are arranged in parallel.
The steering column assisted EPS has low cost and is widely used. The gear assisted EPS is a motor disposed near a gear. The final output end of the rack power-assisted EPS is a rack close to a tire, so that the power-assisted loss is small; in addition, the actuator is far away from the driver, has the advantages of smaller sound and smaller vibration, and is mostly used for high-grade vehicles. The actuators and controllers of the rack-assisted EPS are uniformly distributed in the engine compartment, and the rack-assisted EPS is required to have heat resistance, water resistance and other performances, so that the cost of the system is increased.
The control method provided by the present embodiment is not limited to the EPS that is applied to any one of the torque sensors, the EPS electronic control unit, the motor, and the decelerator described above.
Fig. 2 is a flowchart of an EPS assist mode control method provided in the present embodiment.
The method comprises steps S10-S30. Wherein step S10, the current vehicle speed, the lateral acceleration and the steering torque of the steering wheel are obtained.
In this embodiment, a vehicle speed signal is collected by a vehicle speed sensor, a lateral acceleration signal is collected by a lateral acceleration sensor, and a torque signal of a steering wheel is collected by a torque sensor.
And step S20, determining a proportion coefficient according to the vehicle speed and the lateral acceleration. It should be noted that the scaling factor is a fraction between 0 and 1.
Specifically, step S20 includes steps S201-S203.
S201, acquiring a first functional relation of lateral acceleration and steering torque gradient under each vehicle speed condition of a first power-assisted mode, and acquiring a second functional relation of lateral acceleration and steering torque gradient under each vehicle speed condition of a second power-assisted mode. In this embodiment, the first assist mode is Normal mode, and the second assist mode is Sport mode.
It will be appreciated that the functional relationship between the lateral acceleration and the steering torque gradient is determined based on different vehicle speed conditions.
For example, at a same vehicle speed of 20km/h, a functional relationship between the lateral acceleration and the steering torque gradient is determined, and at this time, one lateral acceleration corresponds to one steering torque gradient, and the lateral acceleration and the steering torque gradient are mapped one by one. At 30km/h, there is another set of lateral acceleration and steering torque gradient functions. The present embodiment is not limited to determining the functional relationship of lateral acceleration and steering torque gradient at different vehicle speeds of 10km/h to 120 km/h.
In this embodiment, the second functional relationship between the lateral acceleration and the steering torque gradient in each of the vehicle speed conditions in the first assist mode and the second assist mode is a preset continuous functional relationship. In other words, in the continuous function, the abscissa is the lateral acceleration, the ordinate is the steering torque gradient, the lateral acceleration on the abscissa is continuous, and the steering torque gradient on the ordinate is also continuous.
Fig. 3 shows a graph of the lateral acceleration and the steering torque gradient as a function of the first assist mode, which graph shows the lateral acceleration and the steering torque gradient as a function of the three different vehicle speeds, in particular as a function of the lateral acceleration and the steering torque gradient at 100km/h, 60km/h and 10km/h, respectively, as can be seen from fig. 3, in which mode the steering torque gradient is smaller with increasing vehicle speed at the same lateral acceleration and smaller with increasing lateral acceleration at the same vehicle speed.
Step S202, under the preset vehicle speed condition of a test mode, the real vehicle marks out a test mapping relation between lateral acceleration and steering torque gradients, and the steering torque gradient corresponding to any lateral acceleration in the test mapping relation is between the same preset vehicle speed and two corresponding steering torque gradients in a first functional relation and a second functional relation under the lateral acceleration condition.
When the vehicle is traveling in a curved path, i.e. when there is an output of lateral steering torque, the vehicle will generate a corresponding lateral centripetal acceleration, here with a corresponding virtual turning radius, the larger the lateral acceleration, the larger the corresponding steering holding torque, i.e. the larger the steering torque required for steering. When the vehicle is subjected to an operation stability test, the vehicle is subjected to a fixed steering radius of 50m and a fixed steering angle, whether the steering force gradient of the vehicle is proper or not can be judged according to the lateral acceleration-steering torque gradient, if the gradient is overlarge, namely, the steering moment is increased greatly along with the increase of the lateral acceleration, at the moment, the change of the force feeling on the hand of a driver is obvious, the corresponding steering holding force is larger, and the driver feels heavy in steering; when the steering torque increases less (the gradient of change is smaller) as the vehicle lateral acceleration increases, the driver feels the steering force lighter.
The step S202 further includes a test mode determining step, and specifically, the test mode determining step includes:
determining a functional relationship f of the first assist mode steering torque and the EPS-assist current 1 (x) And a second power-assisted mode steering torque and EPS-assisted current function f 2 (x)；
The functional relation g (x) between steering torque and EPS-assist current in the test mode satisfies the following conditions:
g(x)＝[f 1 (x)+f 2 (x)]/2。
during actual vehicle calibration, EPS outputs according to the new power-assisted current rule, and in the calibration process, the steering torque gradient corresponding to any lateral acceleration in the third mapping relation is enabled to be between the two steering gradients corresponding to the first mapping relation and the second mapping relation under the same preset vehicle speed and lateral acceleration conditions
It will be appreciated that since the functional relationship between the steering torque and the EPS assist current in the first and second assist modes is calibrated, the EPS output current in the test mode is also calibratable, and based thereon, a real vehicle test is performed.
It should be noted that, because of the real vehicle calibration, in order to improve the calibration efficiency of the test mapping relationship in step S202, a vehicle speed condition is set according to the vehicle speed interval. That is, by defining the speed section, the map relationship in which the same lateral acceleration and steering torque gradient are associated with any speed in the speed section is determined. Thereby greatly reducing the calibration quantity and improving the calibration efficiency.
For example, the same mapping relation between lateral acceleration and steering torque gradient is determined in the vehicle speed range of 20km/h-24 km/h. When the speed is any speed value in the speed interval of 20km/h-24km/h, the same mapping relation is determined.
It can be understood that the above embodiment is to set the real vehicle calibration of the vehicle speed interval with the vehicle speed difference of 5km/h, and determine the mapping relationship between the corresponding lateral acceleration and the steering torque gradient.
Further, considering that different response time requirements exist when the real vehicle is calibrated at different vehicle speeds, the difference of the response time affects different braking distances, so that in the embodiment, the vehicle speed interval setting set when the real vehicle is calibrated is not identical.
Specifically, a high vehicle speed range and a low vehicle speed range are preset. The vehicle speed difference dividing the individual vehicle speed section in the low vehicle speed range is larger than the vehicle speed difference of the individual vehicle speed section in the high vehicle speed range.
For example, a vehicle speed of 30km/h or less is preset as a low vehicle speed range, and a vehicle speed of 90km/h or more is set as a high vehicle speed range.
Setting a vehicle speed interval with a vehicle speed difference of 10km/h in a low speed range: 0-10km/h,10-20km/h,20km/h-30km/h.
Setting a vehicle speed interval with a vehicle speed difference of 5km/h in a high speed range: 90km/h-95km/h,95km/h-100km/h,100km/h-105km/h,105km/h-110km/h, etc.
It should be noted that the specific setting of the high speed range and the low speed range may be calibrated according to actual conditions or test conditions, and different vehicle speed differences may be set in different ranges, and the embodiment is not limited thereto.
And step 203, determining a proportionality coefficient according to the first functional relation, the second functional relation and the test mapping relation.
Specifically, step S203 includes: s2031 to S2034.
S2031, determining a plurality of target lateral accelerations according to the test results.
In this embodiment, the following target lateral acceleration is determined: 0.5m/s 2 、1m/s 2 、1.5m/s 2 、2m/s 2 、2.5m/s 2 、3m/s 2 、3.5m/s 2 、4m/s 2 、4.5m/s 2 、5m/s 2 、5.5m/s 2 、6m/s 2 。
S2032, substituting the first functional relation and the second functional relation into each lateral acceleration to respectively determine steering torque gradients, taking the steering torque gradients determined by the test mapping relation as a proportionality coefficient input value, and taking the steering torque gradients as a lower boundary value and an upper boundary value.
At 1m/s 2 For example, the first and second functional relationships are substituted respectively, and the two steering torque gradients are determined as the lower boundary value y1 and the upper boundary value y 2 . It will be appreciated that the upper boundary value y 2 Greater than the lower boundary value y 1 . Using steering torque gradient determined by test mapping relation as a proportionality coefficient input value x 1 。
S2033, inputting the proportionality coefficient to the value x 1 And lower boundary y 2 Dividing the difference between the upper boundary value y1 and the lower boundary value y 2 Is determined as the initial scaling factor corresponding to the lateral acceleration. I.e. to correspond to 1m/s 2 Is the initial ratio k of (2) 1 。
I.e. to 0.5m/s thereafter 2 、1.5m/s 2 、2m/s 2 、2.5m/s 2 、3m/s 2 、3.5m/s 2 、4m/s 2 、4.5m/s 2 、5m/s 2 、5.5m/s 2 、6m/s 2 The corresponding initial ratio k2 … … k11 is determined.
S204, performing average value calculation on initial proportional coefficients corresponding to the lateral accelerations, and determining the initial proportional coefficients as proportional coefficients.
For example, the sum of k1, k2 … … k11 may be divided by 11 as the final scaling factor.
In this embodiment, the scaling factor is determined using weighted average calculation.
Each initial proportional coefficient corresponds to a weighting coefficient; the weighting coefficient of the initial scaling factor corresponding to the lateral acceleration smaller than the nominal lateral acceleration is larger than that of the initial scaling factors corresponding to the rest lateral acceleration.
In the present embodiment, the nominal lateral acceleration is set to 3m/s 2 The steering torque gradient is larger in consideration of the smaller lateral acceleration, and thus, in the present embodiment, 0.5m/s 2 -3 m/s 2 The weighting coefficient of the initial scaling factor of (2) is greater than 3m/s 2 -6 m/s 2 Is used for the initial scaling factor of the model (a). By adding the weighting coefficient, when the mean value is calculated, the initial scaling coefficient smaller than the calibrated lateral acceleration has larger influence on the final scaling coefficient, and the actual result has better effect.
It should be noted that, the weighting coefficient may be set preferentially, and then adjusted according to the calibration of the real vehicle.
It should be noted that the method may be performed under specific conditions, in other words, when the specific conditions are not met, the EPS is controlled in the first assist mode and the second assist mode that are still present.
Before step S20, it is determined that the vehicle speed is within a preset speed interval while the lateral acceleration is within a preset acceleration interval.
Specifically, the above condition determination includes: the method comprises the steps of determining that the vehicle speed is above a first preset vehicle speed or below a second preset vehicle speed, wherein the first preset vehicle speed is larger than the second preset vehicle speed. And determining that the lateral acceleration is less than the preset acceleration.
It can be understood that the method divides three sections by the vehicle speed, the second preset vehicle speed is lower than the first preset vehicle speed, and the second preset vehicle speed is higher than the first preset vehicle speed, and the method also divides two sections according to the lateral acceleration. And when the current vehicle speed is higher than the first preset vehicle speed and the lateral acceleration is smaller than the preset acceleration, or the vehicle speed is lower than the second preset vehicle speed and the lateral acceleration is smaller than the preset acceleration, performing step S30.
In this embodiment, the first preset vehicle speed is 90km/h, the second preset vehicle speed is 30km/h, and the preset lateral acceleration is set to 3m/s 2 。
For example, at a vehicle speed of 100km/h, at a lateral acceleration of 2m/s 2 The corresponding steering wheel torque increases relatively quickly, namely, a certain steering resistance sense is maintained, and the stability characteristic of the vehicle is maintained.
And at 10km/h, at lateral acceleration 2m/s 2 The moment change gradient is reduced, the proper steering force is maintained, and the comfort of the steering force is ensured.
It should be noted that, the first preset vehicle speed, the second preset vehicle speed, and the preset lateral acceleration are not limited to the values of the above embodiments.
And step S30, determining a final assistance current according to the first assistance current in the first assistance mode and the second assistance current in the second assistance mode under the conditions of the vehicle speed and the steering torque and the proportionality coefficient.
It will be appreciated that the assist current due to the current two assist modes can be determined based on both the assist current at the current vehicle speed and the steering torque conditions and the scaling factor determined by step S20.
Specifically, step S30 includes determining a final assist current by a convex combination algorithm according to a first assist current calibrated in a first assist mode at a current vehicle speed and a steering torque and a second assist current, a first parameter, a second parameter, and a scaling factor in a second assist mode.
For example, the current vehicle speed is 90km/h, the steering torque is 1.5 N.m, and the first assist current of the first assist mode corresponding to the condition is determined to be I A The second boosting current of the second boosting mode is I B The first parameter is 0, the second parameter is 1, the proportionality coefficient k, and the final assisting current I is determined by a convex combination algorithm according to the data:
I＝k·I A +(1-k)·I B 。
after the final assist current is determined, the output is performed based on the assist current. It is possible to obtain a current different from the current first assist mode or second assist mode, that is, even if one of the assist modes is selected, the current approaching the assist mode is finally outputted.
According to the control method, the vehicle stability characteristic and the hand feeling feedback force of the driver are judged according to the vehicle speed, the lateral acceleration and the characteristic index steering torque gradient for evaluating the vehicle steering stability, so that the proportionality coefficient among different steering assistance modes is obtained, the force sense of the steering operation force of the driver is properly corrected, and the flexible and smooth force sense change is ensured.
The present embodiment further provides an EPS assist mode control device, and fig. 4 is a schematic diagram of the EPS assist mode control device provided in the present embodiment.
As shown in fig. 4, the EPS assist mode control device includes a first module 41, a second module 42, and a third module 43.
The first module 41 is used to obtain the current vehicle speed, lateral acceleration and steering torque of the steering wheel.
The second module 42 is configured to determine a scaling factor based on the vehicle speed and the lateral acceleration.
The third module 43 is configured to determine a final assist current based on the first assist current in the first assist mode and the second assist current in the second assist mode under the vehicle speed and the steering torque condition and the scaling factor.
It should be noted that, the EPS assist mode control device provided in this embodiment may also be a computer program (including program code) running in a computer device, for example, the EPS assist mode control device is an application program, and may be used to execute corresponding steps in the above method provided in the embodiment of the present application.
In some possible implementations, the EPS assist mode control device provided in this embodiment may be implemented by combining software and hardware, and as an example, the EPS assist mode control device in this embodiment may be a processor in the form of a hardware decoding processor that is programmed to perform the EPS assist mode control method provided in this embodiment, for example, the processor in the form of a hardware decoding processor may use one or more application specific integrated circuits (ASIC, application Specific Integrated Circuit), digital signal processor (digital signal processor, DSP), programmable logic device (PLD, programmable Logic Device), complex programmable logic device (CPLD, complex Programmable Logic Device), field programmable gate array (FPGA, field-Programmable Gate Array), or other electronic components.
In some possible implementations, the control device for the EPS assist mode provided in this embodiment may be implemented in a software manner, which may be software in the form of a program, a plug-in, or the like, and includes a series of modules to implement the control method provided in the embodiment of the present invention.
The EPS assistance mode control device provided by the embodiment obtains the current vehicle speed, the lateral acceleration and the steering torque of the steering wheel; determining a proportionality coefficient according to the vehicle speed and the lateral acceleration; determining final power-assisted current according to a first power-assisted current in a first power-assisted mode and a second power-assisted current in a second power-assisted mode under the conditions of vehicle speed and steering torque and a proportion coefficient, judging vehicle stability characteristics and hand-feel feedback force of a driver according to the vehicle speed, lateral acceleration and a characteristic index steering torque gradient for evaluating vehicle steering stability, further obtaining proportion coefficients among different steering power-assisted modes, finally realizing moderate correction of the force sense of steering operation force of the driver, and ensuring flexible smooth force sense change.
The embodiment of the present application further provides an electronic device, and fig. 5 is a schematic structural diagram of the electronic device according to the embodiment of the present application, as shown in fig. 5, an electronic device 1000 in the embodiment may include: processor 1001, network interface 1004, and memory 1005, and in addition, the electronic device 1000 may further include: a user interface 1003, and at least one communication bus 1002. Wherein the communication bus 1002 is used to enable connected communication between these components. The user interface 1003 may include a Display (Display), a Keyboard (Keyboard), and the optional user interface 1003 may further include a standard wired interface, a wireless interface, among others. The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface). The memory 1004 may be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The memory 1005 may also optionally be at least one storage device located remotely from the processor 1001. As shown in fig. 5, an operating system, a network communication module, a user interface module, and a device control application may be included in the memory 1005, which is a type of computer-readable storage medium.
In the electronic device 1000 shown in fig. 5, the network interface 1004 may provide a network communication function; while user interface 1003 is primarily used as an interface for providing input to a user; and the processor 1001 may be used to invoke a device control application stored in the memory 1005 to implement:
acquiring the current vehicle speed, lateral acceleration and steering torque of a steering wheel;
determining a scaling factor from the vehicle speed and the lateral acceleration;
and determining final assistance current according to the first assistance current in the first assistance mode and the second assistance current in the second assistance mode under the vehicle speed and the steering torque condition and the proportionality coefficient.
It should be appreciated that in some possible embodiments, the processor 1001 described above may be a central processing unit (central processing unit, CPU), which may also be other general purpose processors, DSP, ASIC, FPGA or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The memory may include read only memory and random access memory and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store information of the device type.
In a specific implementation, the electronic device 1000 may execute, through each functional module built in the electronic device, an implementation manner provided by each step of the control method, and specifically, the implementation manner provided by each step may be referred to, which is not described herein again.
The electronic equipment provided by the embodiment obtains the current vehicle speed, the lateral acceleration and the steering torque of the steering wheel; determining a proportionality coefficient according to the vehicle speed and the lateral acceleration; determining final power-assisted current according to a first power-assisted current in a first power-assisted mode and a second power-assisted current in a second power-assisted mode under the conditions of vehicle speed and steering torque and a proportion coefficient, judging vehicle stability characteristics and hand-feel feedback force of a driver according to the vehicle speed, lateral acceleration and a characteristic index steering torque gradient for evaluating vehicle steering stability, further obtaining proportion coefficients among different steering power-assisted modes, finally realizing moderate correction of the force sense of steering operation force of the driver, and ensuring flexible smooth force sense change.
The embodiment of the present application further provides a computer readable storage medium, where the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement each step in the EPS assist mode control method in the foregoing embodiment, and specifically, refer to an implementation manner provided by each step, which is not described herein in detail.
The computer readable storage medium provided by the present embodiment is configured to store a current vehicle speed, a lateral acceleration, and a steering torque of a steering wheel; determining a proportionality coefficient according to the vehicle speed and the lateral acceleration; determining final power-assisted current according to a first power-assisted current in a first power-assisted mode and a second power-assisted current in a second power-assisted mode under the conditions of vehicle speed and steering torque and a proportion coefficient, judging vehicle stability characteristics and hand-feel feedback force of a driver according to the vehicle speed, lateral acceleration and a characteristic index steering torque gradient for evaluating vehicle steering stability, further obtaining proportion coefficients among different steering power-assisted modes, finally realizing moderate correction of the force sense of steering operation force of the driver, and ensuring flexible smooth force sense change.
It should be understood that, although the steps in the flowcharts of the figures are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited in order and may be performed in other orders, unless explicitly stated herein. Moreover, at least some of the steps in the flowcharts of the figures may include a plurality of sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, the order of their execution not necessarily being sequential, but may be performed in turn or alternately with other steps or at least a portion of the other steps or stages.
The foregoing is only a partial embodiment of the present application, and it should be noted that, for a person skilled in the art, several improvements and modifications can be made without departing from the principle of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims (14)

1. The EPS assistance mode control method is characterized by comprising the following steps of:
acquiring the current vehicle speed, lateral acceleration and steering torque of a steering wheel;
determining a scaling factor from the vehicle speed and the lateral acceleration;
and determining final assistance current according to the first assistance current in the first assistance mode and the second assistance current in the second assistance mode under the vehicle speed and the steering torque condition and the proportionality coefficient.
2. The EPS assist mode control method according to claim 1, characterized in that the step of determining a proportionality coefficient according to the vehicle speed and the lateral acceleration includes:
acquiring a first functional relation between lateral acceleration and steering torque gradient under each vehicle speed condition of a first power-assisted mode and a second functional relation between lateral acceleration and steering torque gradient under each vehicle speed condition of a second power-assisted mode;
under the preset vehicle speed condition of a test mode, the real vehicle marks out a test mapping relation between lateral acceleration and steering torque gradient, and the steering torque gradient corresponding to any lateral acceleration in the test mapping relation is between the two corresponding steering torque gradients in the first functional relation and the second functional relation under the same preset vehicle speed and lateral acceleration condition;
and determining a proportionality coefficient according to the first functional relation, the second functional relation and the test mapping relation.
3. The EPS assist mode control method as set forth in claim 2, wherein the step of calibrating the test map of the lateral acceleration and the steering torque gradient for the real vehicle under the preset vehicle speed condition of the test mode includes:
and determining a preset vehicle speed condition according to the vehicle speed interval.
4. The EPS assist mode control method according to claim 3, characterized in that the vehicle speed section is set according to the magnitude of the vehicle speed difference in different vehicle speed ranges.
5. The EPS assist mode control method according to claim 4, characterized in that the step of setting the vehicle speed section in accordance with the magnitude of the vehicle speed difference in the different vehicle speed ranges includes:
a high vehicle speed range and a low vehicle speed range are preset, the vehicle speed difference during the high vehicle speed range setting vehicle speed being smaller than the vehicle speed difference during the low vehicle speed range setting vehicle speed.
6. The EPS assist mode control method according to claim 2, characterized in that the test mode determining step includes:
determining a functional relationship f of the first assist mode steering torque and the EPS-assist current 1 (x) And a second power-assisted mode steering torque and EPS-assisted current function f 2 (x)；
The functional relation g (x) between steering torque and EPS-assisting current in the test mode meets the following conditions:
g(x)＝[f 1 (x)+f 2 (x)]/2。
7. the EPS assist mode control method as set forth in claim 2, wherein the step of determining a scaling factor based on the first functional relationship, the second functional relationship, and the trial mapping relationship includes:
taking a plurality of lateral accelerations, corresponding to each lateral acceleration, respectively determining the steering torque gradient by the first functional relation and the second functional relation as a lower boundary value and an upper boundary value, and taking the steering torque gradient determined by the test mapping relation as a proportionality coefficient input value;
dividing the difference between the input value of the proportionality coefficient and the lower boundary by the difference between the upper boundary value and the lower boundary value to determine an initial proportionality coefficient corresponding to the lateral acceleration;
and carrying out average value calculation on the initial proportional coefficient corresponding to each lateral acceleration, and determining the initial proportional coefficient as the proportional coefficient.
8. The EPS assist mode control method as set forth in claim 7, wherein the average value calculation is a weighted average value calculation, and each initial scaling factor corresponds to a weighting factor;
the weighting coefficient of the initial scaling factor corresponding to the lateral acceleration smaller than the nominal lateral acceleration is larger than that of the initial scaling factors corresponding to the rest lateral acceleration.
9. The EPS assist mode control method according to claim 1, characterized in that the step of determining a final assist current based on a first assist current in a first assist mode and a second assist current in a second assist mode under the vehicle speed and the steering torque condition, and the proportionality coefficient, includes:
and determining final power-assisted current by a convex combination algorithm according to the first power-assisted current calibrated in the first power-assisted mode under the current vehicle speed and the steering torque, the second power-assisted current calibrated in the second power-assisted mode, the first parameter, the second parameter and the proportionality coefficient.
10. The EPS assist mode control method according to any one of claims 1 to 9, characterized in that said determination of the proportionality coefficient based on said vehicle speed and said lateral acceleration further comprises the steps of:
and determining that the vehicle speed is in a preset speed interval, and simultaneously, determining that the lateral acceleration is in a preset acceleration interval.
11. The EPS assist mode control method according to claim 10, characterized in that the step of determining that the vehicle speed is within a preset speed interval and the lateral acceleration is within a preset acceleration interval includes:
determining that the vehicle speed is above a first preset vehicle speed or below a second preset vehicle speed, wherein the first preset vehicle speed is greater than the second preset vehicle speed;
and determining that the lateral acceleration is smaller than a preset acceleration.
12. An EPS assist mode control device, characterized by comprising:
the first module is used for acquiring the current vehicle speed, the lateral acceleration and the steering torque of the steering wheel;
a second module for determining a scaling factor based on the vehicle speed and the lateral acceleration;
and the third module is used for determining a final assistance current according to the first assistance current in the first assistance mode and the second assistance current in the second assistance mode under the condition of the vehicle speed and the steering torque and the proportionality coefficient.
13. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the EPS assist mode control method as claimed in any one of claims 1 to 11 when executing the computer program.
14. A computer-readable storage medium storing computer instructions that cause the computer to execute the steps of the EPS assist mode control method according to any one of claims 1 to 11.
CN202310325147.7A 2023-03-29 2023-03-29 EPS (electric power steering) power assisting mode control method and device, electronic equipment and storage medium Pending CN116461603A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310325147.7A CN116461603A (en) 2023-03-29 2023-03-29 EPS (electric power steering) power assisting mode control method and device, electronic equipment and storage medium

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310325147.7A CN116461603A (en) 2023-03-29 2023-03-29 EPS (electric power steering) power assisting mode control method and device, electronic equipment and storage medium

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CN116461603A true CN116461603A (en) 2023-07-21

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