A software system and a steering column control method, system and vehicle

Abstract

The application relates to a software architecture, a steering column control method and system and a vehicle, the software architecture comprising: a basic function module for providing basic torque control of the vehicle and determining integrated basic function torque; an advanced driving assistance system module for determining system torque of the advanced driving assistance system; a function protection module for determining a torque protection coefficient according to motor data of a motor of the vehicle, adjusting the basic function torque or the system torque using the torque protection coefficient to obtain target torque; and a motor controller module for controlling a steering column of an EPS according to the target torque. By determining the torque protection coefficient according to the motor data of the motor, adjusting the system torque determined by the advanced driving assistance system of the vehicle or the integrated basic function torque of the vehicle using the torque protection coefficient, the accuracy of the steering column control is improved, and thus the problem of low steering column control accuracy is solved.

Description

Technical Field

[0001] This application relates to the field of automotive technology, specifically to a software architecture and a steering column control method, system, and vehicle. Background Technology

[0002] EPS systems are currently a popular and widely used vehicle lateral control device. They are simple in structure and low in cost, but their control is more difficult, especially the realization of high-performance EPS systems, which involves control algorithms, calibration and tuning, and testing and verification.

[0003] The EPS system mainly consists of a steering wheel and steering column, intermediate shaft, rack and pinion mechanism, power steering motor and reducer, ECU, and torque sensor. Its basic working principle is as follows: When the driver turns the steering wheel, the torque sensor detects the torque signal. The ECU collects the torque value, processes it through power steering gain and various compensations to obtain the desired output torque for the motor, and outputs it to the motor controller. The motor outputs the desired torque, which is amplified by the reducer and combined with the driver's torque to rotate the EPS system output shaft. This rotation, via the rack and pinion mechanism, causes the rack to move, which in turn drives the wheels through the steering tie rod and steering knuckle arm, thus steering the vehicle.

[0004] However, the aforementioned EPS controls the car's steering column, but can only provide basic steering control functions. It does not provide more detailed steering column control during the steering process, resulting in low steering column control precision. Summary of the Invention

[0005] This application provides a software architecture, a steering column control method, system, and vehicle to address the problem of low precision in steering column control.

[0006] In a first aspect, this application provides a software architecture, including: a basic function module for providing basic torque control of a vehicle and determining an integrated basic function torque; an advanced driver assistance system module for determining the system torque of the advanced driver assistance system; a function protection module for determining a torque protection coefficient based on motor data of the vehicle motor, and adjusting the basic function torque or the system torque using the torque protection coefficient to obtain a target torque; and a motor controller module for controlling the steering column of the EPS according to the target torque.

[0007] Secondly, this application provides a steering column control method, comprising: determining a torque protection coefficient based on motor data of an automobile motor; adjusting the system torque determined by the advanced driver assistance system of the automobile using the torque protection coefficient, or adjusting the integrated basic function torque of the automobile, to obtain the target torque; and controlling the steering column of the EPS according to the target torque.

[0008] Thirdly, this application provides a steering column control system, comprising: a determining module for determining a torque protection coefficient based on motor data of an automotive motor; an adjusting module for adjusting the system torque determined by the advanced driver assistance system of the vehicle using the torque protection coefficient, or adjusting the integrated basic function torque of the vehicle to obtain the target torque; and a controlling module for controlling the steering column of the EPS according to the target torque.

[0009] Fourthly, this application provides an automobile, including: a steering column control system, configured to determine a torque protection coefficient based on motor data of the automobile motor; adjust the system torque determined by the advanced driver assistance system of the automobile using the torque protection coefficient, or adjust the integrated basic function torque of the automobile to obtain the target torque; control the steering column of the EPS according to the target torque; the steering column is used to steer the automobile when controlled.

[0010] Fifthly, this application provides a steering column control device, comprising: at least one communication interface; at least one bus connected to the at least one communication interface; at least one processor connected to the at least one bus; and at least one memory connected to the at least one bus, wherein the processor is configured to: determine a torque protection coefficient based on motor data of an automotive motor; adjust the system torque determined by an advanced driver assistance system of the vehicle using the torque protection coefficient, or adjust the integrated basic function torque of the vehicle, to obtain the target torque; and control the steering column of the EPS according to the target torque.

[0011] Sixthly, this application also provides a computer storage medium storing computer-executable instructions for executing the steering column control method described in any of the above claims of this application.

[0012] The beneficial effects of this application are: In the process of controlling the steering column, this application first determines the torque protection coefficient based on the motor data of the vehicle's electric motor. Then, if the system torque determined by the vehicle's advanced driver assistance system (ADAS) is obtained, the torque protection coefficient is used to adjust the system torque. If the vehicle's integrated basic function torque is obtained, the integrated basic function torque is adjusted. Either the system torque or the vehicle's integrated basic function torque can be adjusted. This allows for torque adjustment of either the ADAS or the vehicle's integrated basic function torque, resulting in a more precise target torque. Applying this target torque to the steering column improves the torque control accuracy of the steering column and solves the problem of low steering column control precision. Attached Figure Description

[0013] Figure 1 This is a software architecture diagram of this application; Figure 2 This is a flowchart of a steering column control method according to this application; Figure 3 This is a flowchart illustrating the determination of the torque protection coefficient in a steering column control method according to this application. Figure 4 This is a flowchart illustrating the system torque determination method of the steering column control method of this application. Figure 5 A flowchart of the basic functional torque for determining a steering column control method according to this application is provided. Figure 6 This is a flowchart illustrating the determination of various torques in a steering column control method according to this application; Figure 7 This is a schematic diagram of a car steering structure according to this application; Figure 8 This is a control flowchart of a steering column control method according to this application; Figure 9 This is a schematic diagram of a steering column control device according to this application; Figure 10 This is a schematic diagram of a steering column control system according to this application; Figure 11 This is a schematic diagram of a steering column control device according to this application. Detailed Implementation

[0014] The embodiments of this application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be understood that the preferred embodiments are only for illustrating this application and are not intended to limit the scope of protection of this application.

[0015] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0016] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0017] To address the technical problem of low steering column control accuracy in existing technologies, this application provides a software architecture, as well as a steering column control method, system, and vehicle, which can improve the steering column control accuracy.

[0018] Figure 1 This is a schematic diagram of a software architecture according to this embodiment. For example... Figure 1 As shown, it includes: Basic function module 101 is used to provide basic torque control for the vehicle and determine the integrated basic function torque; Advanced driver assistance system module 102 is used to determine the system torque of the advanced driver assistance system; The functional protection module 103 is used to determine the torque protection coefficient based on the motor data of the automobile motor, and adjust the basic functional torque or the system torque using the torque protection coefficient to obtain the target torque; The motor controller module 104 is used to control the steering column of the EPS according to the target torque.

[0019] The software architecture in this embodiment is a structure used to constrain software. The software architecture includes multiple modules and the functions of multiple modules. Under this architecture, programmers can write code for related functions by using the constraints of the architecture, thereby implementing the architecture. As for the content of the code, it is not necessarily limited to a certain language or certain code, as long as it can implement the functions of the software architecture.

[0020] Under this software architecture, this embodiment presents a flowchart of a steering column control method using this software architecture to control the steering column, as follows: Figure 2 As shown, it includes: S201, determine the torque protection coefficient based on the motor data of the automotive motor; S202, when the system torque determined according to the advanced driver assistance system of the above-mentioned vehicle is obtained, the system torque is adjusted using the torque protection coefficient to obtain the target torque; S203, when the above system torque is not obtained, the integrated basic functional torque of the above vehicle is obtained, and the integrated basic functional torque is adjusted using the above torque protection coefficient to obtain the above target torque; S204, control the steering column of the EPS according to the above target torque.

[0021] In existing technologies, the steering column control of EPS systems only achieves basic functions such as power assist, damping, self-centering, and end-of-life protection, resulting in poor steering column control accuracy and unpleasant steering wheel feel for the driver. To address this issue, this embodiment proposes a method. The vehicle mentioned in the method includes an Electric Power Steering (EPS) system. This EPS system consists of a steering wheel and steering column, intermediate shaft, rack and pinion mechanism, power assist motor and reducer, Electronic Control Unit (ECU), and torque sensor. When the driver turns the steering wheel, the torque sensor detects a torque signal. The ECU collects the torque value of this signal, processes it through power assist gain and various compensations to obtain the desired output torque of the motor, and outputs this desired output torque to the motor controller. The motor controller outputs the desired torque, which is amplified by the reducer and combined with the driver's torque to rotate the EPS steering column. This rotation, via the rack and pinion mechanism, moves the rack, which in turn drives the wheels through the tie rod and steering knuckle arm, thus steering the vehicle.

[0022] The target torque mentioned in this embodiment can be the motor output torque, or the torque amplified by the motor output torque after being reduced by a reducer. If there is a torque exerted by the driver turning the steering wheel, the target torque and the driver's torque are superimposed to rotate the EPS system output shaft. If it is an autonomous driving system, the target torque acts solely on the EPS system output shaft.

[0023] The aforementioned motor is a device used to output the target torque. The motor outputs the target torque of the corresponding magnitude according to the instruction.

[0024] The aforementioned advanced driver assistance systems (ADAS) can be either autonomous driving systems or driver assistance systems, possessing the ability to independently control the vehicle or assist the user in controlling it. Examples include autonomous driving, lane keeping assist, and intelligent obstacle avoidance. If an ADAS is activated, the steering wheel may be held in a certain position under the system's control, causing the tires to point at a specific angle, achieving automatic turning. In this case, it's necessary to determine the required torque to maintain the correct tire angle; that is, to determine the corresponding system torque for the ADAS.

[0025] The aforementioned integrated basic functional torque refers to the torque required by a car to achieve the basic functions of its EPS system, such as power assist, damping, self-centering, and end-of-life protection, plus torque compensation. Torque compensation is designed to compensate for torque loss when the car is under torque control, resulting in more accurate torque control and a more comfortable driving experience. For example, calculating the torque required to center the steering wheel, adding torque compensation, and then calculating the required torque after compensation, gives the torque needed to center the steering wheel. Compared to simply calculating the torque required to center the steering wheel, the compensated torque provides a more comfortable feel and more accurate torque control. Therefore, the calculated compensated torque is considered the integrated basic functional torque.

[0026] In this embodiment, instead of directly controlling the steering column of the EPS system according to the system torque or integrated basic function torque corresponding to the advanced driver assistance system, a torque protection coefficient is used to adjust the system torque or integrated basic function torque. The adjusted torque is then used as the target torque to control the steering column of the EPS system. Because the target torque obtained by this method is adjusted based on the actual situation of the motor to adjust the calculated system torque or integrated basic function torque, the torque value is more accurate, resulting in higher control precision for the steering shaft of the EPS system.

[0027] In this embodiment, the system torque determined by the advanced driver assistance system (ADAS) and the integrated basic function torque are mutually exclusive. One of the two torques is adjusted using a torque protection coefficient to determine the target torque. If the system torque is used to determine the target torque in the autonomous or assisted driving state, the system torque is used to control the EPS steering column. If the user is manually driving, in addition to the torque applied to the steering wheel, torque compensation is also considered. The integrated basic function torque is determined based on the torque compensation, and then the target torque is determined from the integrated basic function torque. The EPS steering column is then controlled using the torque applied to the steering wheel and the target torque.

[0028] In this embodiment, it can first be determined whether there is a system torque determined by an advanced driver assistance system. If there is a system torque, the system torque is adjusted using a torque protection coefficient as the target torque. If no system torque is received, the integrated basic function torque is obtained, and the integrated basic function torque is adjusted using a torque protection coefficient as the target torque. This can protect the autonomous driving or assisted driving situation first. If the user is driving manually, the system torque cannot be obtained, and the system enters the situation of determining the target torque using the integrated basic function torque.

[0029] In the process of controlling the steering column, this application first determines the torque protection coefficient based on the motor data of the vehicle's electric motor. Then, if the system torque determined by the vehicle's advanced driver assistance system is obtained, the torque protection coefficient is used to adjust the system torque. If the system torque is not obtained, the torque of the vehicle's integrated basic function is adjusted. Thus, the torque of the advanced driver assistance system or the torque of the vehicle's integrated basic function can be adjusted according to whether the advanced driver assistance system is currently activated, resulting in a more accurate target torque. The target torque is then applied to the steering column, improving the torque control accuracy of the steering column and solving the problem of low steering column control accuracy.

[0030] In one example, the motor data for a car motor includes at least the motor speed and motor temperature. The motor speed can be n revolutions per second (n RPM). The specific speed depends on the actual situation. The motor temperature can be the measured internal temperature of the motor. If the internal temperature cannot be measured, the surface temperature or the temperature of the space where the motor is located can be measured. Figure 2 This is an exemplary flowchart for determining the torque protection coefficient based on the motor data of an automotive motor. For example... Figure 2 As shown, it includes: S301, obtain the motor speed and motor temperature of the aforementioned automotive motor; S302, when the above motor speed or the above motor temperature is abnormal, the above torque protection coefficient is reduced.

[0031] In this embodiment, after calculating the system torque or integrated basic function torque, the motor outputs the corresponding torque according to the command to control the steering shaft of the EPS system. At this time, it is necessary to check whether the motor speed and motor temperature are normal, and adjust the output torque accordingly to output the target torque.

[0032] Since both the system torque and the integrated basic function torque need to be adjusted using a torque protection factor, it is necessary to determine how to calculate the torque protection factor.

[0033] Motor temperature and speed can reflect the current state of the motor to some extent. For example, a motor stall phenomenon may occur, where the motor speed decreases or even drops to zero, but torque is still output. Stall phenomena can be caused by various factors, including excessive motor load, mechanical failure of the driven component, and bearing damage. If a stall occurs, the motor's power factor is extremely low, and the current can reach up to seven times the rated current; prolonged stalling can burn out the motor. Therefore, when a motor stall occurs, the stall torque and torque change rate should be limited according to the stall condition. This can be achieved by lowering the torque protection coefficient, multiplying the calculated system torque or integrated basic function torque by the torque protection coefficient, resulting in a lower target torque value, thus reducing the stress on the motor.

[0034] In this embodiment, the torque protection coefficient can be determined based on either motor temperature or motor speed. There is a correlation between motor temperature and the torque protection coefficient: once the motor temperature exceeds its normal range, the higher the motor temperature, the larger the torque protection coefficient. Similarly, there is a correlation between motor speed and the torque protection coefficient: once the motor speed exceeds its normal range, the higher the motor speed, the larger the torque protection coefficient. If the torque protection coefficient is determined based on both motor temperature and motor speed, the greater the extent to which either exceeds its normal range, the larger the torque protection coefficient will be. Furthermore, the rate of change of the torque protection coefficient is greater than the rate of change when determining the torque protection coefficient solely based on either motor temperature or motor speed.

[0035] Determining the torque protection coefficient by simultaneously considering motor temperature and motor speed allows for more accurate determination of the torque protection coefficient. The determined torque protection coefficient is then used to adjust the coefficient torque or integrated basic function torque to obtain the target torque. This allows the motor to output the target torque, resulting in a smaller output target torque when the motor malfunctions, thus reducing the stress on the motor.

[0036] In one example, before adjusting the system torque or integrated basic function torque of the advanced driver assistance system based on the motor's condition, the vehicle's integrated basic function torque and system torque must be calculated. The calculated values ​​will differ depending on the vehicle's condition and environment. Figure 4 It is a method for determining the torque of a system, including: S401, Determine the current functional mode of the aforementioned advanced driver assistance system; S402, the required torque under the current functional mode is determined as the system torque.

[0037] In this embodiment, calculating the system torque of the advanced driver assistance system (ADAS) requires examining the current functional mode of the vehicle's ADAS. The current functional mode can be various, such as torque control, angle control, lane departure warning, autonomous driving, adaptive cruise control, lane keeping assist, emergency obstacle avoidance, and intelligent speed control. For torque control, this refers to the amount of torque output controlled under the ADAS. For angle control, it refers to the steering angle controlled under the ADAS; at that steering angle, the required torque output is calculated for steering. For lane departure warning and lane keeping assist, the vehicle's current lane is identified; if it approaches or deviates from the lane, the required torque is determined to return to or maintain the original lane. For autonomous driving and adaptive cruise control, the vehicle speed is identified, and data from multiple sensors is acquired to calculate the torque required by the vehicle's motor to maintain stable driving, etc. These are examples of various scenarios. In summary, for the functions of a vehicle's ADAS, the required system torque must be calculated for each function; this system torque is the torque necessary to achieve the functions of the ADAS.

[0038] For example, taking autonomous driving and lane keeping as an example, during autonomous driving, multiple sensors in the car identify the lane the vehicle is in and perform lane keeping. To perform autonomous driving and lane keeping, it's necessary to determine whether the car is in the center of the lane and whether it's too close or too far from the lane boundary. If it's not in the center of the lane, it's necessary to determine how much steering wheel rotation is needed to return the car to the center. This requires calculating the required system torque under the advanced driver assistance system's functions to bring the car back to the center. Therefore, the calculated system torque is the force that is desired to act on the steering column of the EPS system.

[0039] Before applying the calculated system torque to the steering column of the EPS system, this embodiment adjusts the system torque using the aforementioned torque protection coefficient. After adjustment, a target torque is obtained, and the force is applied to the steering column of the EPS system according to this target torque value. For example, based on the motor's condition, if the torque protection coefficient is determined to be 0.95, the originally calculated system torque is multiplied by 0.95, and the result is applied to the steering column of the EPS system. This achieves the car returning to the center of the lane while reducing the pressure on the motor and making the process of the car returning to the center of the lane smoother, avoiding sudden left-right swaying of the car.

[0040] In this embodiment, since the matching system torque is calculated based on the current functional mode of the vehicle's advanced driver assistance system, the matching system torque can be determined according to the actual driving state, ensuring that the determined system torque meets the driving state and driving needs, thus improving the accuracy of the system torque.

[0041] Figure 5 It is a method for determining the integrated basic function torque, including: S501, obtain the low-frequency assist torque, high-frequency assist torque, self-aligning torque, end protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque of the above-mentioned vehicle. S502, the obtained torque and assist torque are calculated according to the preset formula, and the result is used as the above-mentioned integrated basic function torque.

[0042] Since the system torque output by the Advanced Driver Assistance System (ADAS) is zero, or no ADAS system torque can be obtained, it indicates that the driver has not activated the ADAS function and is driving manually. Therefore, the integrated basic function torque generated during manual driving can be calculated. When driving manually, the driver first exerts a control force on the steering wheel, which is based on the driver's subjective intention and is used to control the car's steering or straight-line driving. During this process, to improve the driver's feel and the accuracy of the EPS system's steering column control, an integrated basic function torque can be calculated. This integrated basic function torque is a torque obtained by combining multiple compensations and adjustments. For example, based on the driver's manual driving, multiple torques are compensated (hereinafter referred to as multiple torques), including low-frequency assist torque, high-frequency assist torque, self-centering torque, end-protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque. This improves the driver's driving feel and increases the accuracy of the EPS system's steering column control.

[0043] The aforementioned compensation of multiple torques involves merging these torques into a single total torque, known as the integrated basic functional torque. This integrated basic functional torque is not directly applied to the steering column of the EPS system. Instead, it is first adjusted using a torque compensation coefficient determined from the motor data to obtain a target torque. Then, the torque generated by the driver's manual driving is combined with the target torque and applied to the steering column of the EPS system.

[0044] When calculating the above multiple torques into an integrated basic functional torque, a preset formula can be used for calculation. The preset formula can be a mathematical formula or operator used to calculate the low-frequency assist torque, high-frequency assist torque, self-aligning torque, end protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque to obtain the integrated basic functional torque.

[0045] In this embodiment, for the aforementioned multiple torques, not all torques may be used when calculating the integrated basic function torque. Torques are not used because the calculated torque is too small or zero in the current environment, or the current environment is not suitable for that torque. Therefore, these torques are deleted during calculation, and the remaining torques are used to calculate the integrated basic function torque.

[0046] For example, the integrated basic function torque can be calculated using the following formula (1): (1) in, Indicates the integrated basic function torque. Indicates low-frequency assist torque. Indicates high-frequency assist torque. This indicates the friction compensation torque. Indicates the restoring torque. Indicates the end protection torque. Indicates the damping torque. Indicates the inertial compensation torque. This indicates the suppression and compensation torque for wheel imbalance. Indicates the oscillation compensation torque. This represents the torque steering compensation torque. The integrated basic function torque is obtained through the calculation of multiple torques.

[0047] Since the integrated basic function torque in this embodiment takes into account torque compensation for various situations when the driver is manually driving, it can be adapted to various environments or vehicle states when the driver is manually driving, ensuring a wide range of applicability. In various situations, the integrated basic function torque that matches the vehicle state and environment can be calculated, thereby compensating for the driving feel of the vehicle.

[0048] In one embodiment, if the integrated basic function torque is to be calculated, the values ​​of the low-frequency assist torque, high-frequency assist torque, self-aligning torque, end protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque must be known. Figure 6 This is a flowchart illustrating the calculation process for the values ​​of the various torques mentioned above. (For example...) Figure 6 As shown, it includes: S601, obtain the steering wheel torque, steering wheel angle, vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage of the aforementioned vehicle. S602, based on the obtained steering wheel torque, steering wheel angle, vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage, determines the vehicle's low-frequency assist torque, high-frequency assist torque, self-centering torque, end protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque.

[0049] In this embodiment, data collected by the vehicle's sensors and data received by the Controller Area Network (CAN) can be used to calculate the aforementioned multiple torques. For example, the vehicle's torque and angle sensors (TAS) detect steering wheel torque and angle signals, the vehicle's temperature sensors detect motor temperature, and the vehicle's angle sensors detect motor angle. The CAN network can receive vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage from the Vehicle Motion Control (VMC), thereby obtaining multiple data such as steering wheel torque and angle signals, motor temperature, motor angle, vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage. These multiple data are then used to calculate the aforementioned multiple torques.

[0050] For the aforementioned torques, not every torque requires all of the aforementioned data. For each torque, at least one of the aforementioned data can be used to determine its value; one data point, multiple data points, or all data points can be used. For example, the low-frequency and high-frequency power assist torques mentioned above can be calculated using the vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage, without needing to use steering wheel torque and steering wheel angle. Similarly, the damping torque mentioned above can be calculated using steering wheel torque, steering wheel angle, vehicle speed, yaw rate, and wheel speed.

[0051] In this embodiment, a torque-data mapping table can be pre-defined. For each torque, the table can be consulted to find the data needed to calculate that torque, and the torque can be calculated based on the value of that data. The method for calculating the torque value using data can also differ for each torque. For example, calculating the torque value using only one set of data establishes a functional relationship between the data and the torque, allowing the torque value to be determined in a two-dimensional coordinate system. However, if at least two sets of data are used to calculate the torque value, the data must be mapped to a multi-dimensional space to determine the torque value matching the multiple sets of data in that space. For example, when determining the friction compensation torque using two sets of data, the two sets of data are mapped to a three-dimensional space to determine the value of the friction compensation torque in the third dimension.

[0052] In this embodiment, since the user's driving environment involves a variety of factors, multiple data of the car are collected through the car's sensors and CAN network. Based on the multiple data, the value of each torque is calculated. Then, the multiple torques are calculated and integrated into basic torque compensation using the above formula (1). This results in torque compensation that is suitable for various situations and environments, making the car's torque compensation more applicable and the torque compensation in each scenario more accurate, thus improving the user's driving feel.

[0053] On another front, since users' driving environments are diverse, the calculation of the integrated basic function torque varies depending on the environment. The above formula (1) can be adjusted during calculation. For example, depending on the driving state of the car, the calculation of the integrated basic function torque may not use all of the above torques, or the calculated value of some torques may be zero. For instance, when the driver is driving the car in a straight-line driving state, the friction compensation torque may not be used, or the calculated result of the friction compensation torque may be zero, having no impact on the integrated basic function torque. However, when the driver is turning the car, the calculation of the integrated basic function torque will use the friction compensation torque, but the end-protection torque may not be used. Therefore, in this embodiment, for various driving situations, the torques to be used to calculate the integrated basic function torque can be determined according to the driving state. Alternatively, if all torques are used to calculate the integrated basic function torque, some torques may have a smaller impact on the integrated basic function torque under certain driving states, thus matching the driving state. In other words, depending on the driving conditions, if all torques are used to calculate the integrated basic function torque, the operator in the preset formula can be determined based on the driving conditions. For example, when the driver is driving a car in a straight-line driving state, a subtraction sign (which could originally be a plus sign) can be used for the friction compensation torque to subtract the compensation, or a coefficient between 0 and 1 can be added to the friction compensation torque to reduce its impact on the integrated basic function torque. Conversely, for torques that have a greater impact in straight-line driving states, a coefficient greater than 1 can be added to increase their influence on the integrated basic function torque.

[0054] In this embodiment, since various driving states are taken into account, different torques can be used to calculate the integrated basic function torque for different driving states. Alternatively, when calculating the integrated basic function torque using all records, a coefficient can be used to adjust the influence of the torques used and those not frequently used in that driving state, so that the calculated integrated basic function torque matches the driving state.

[0055] Figure 7This is a schematic diagram of the vehicle steering structure in this embodiment. When the driver turns the steering wheel 701, the torque sensor 702 detects the torque signal. The microcontroller (Electronic Control Unit, ECU) collects the torque value, processes it through power assist gain and various torque compensations to obtain the desired output torque of the motor, and outputs it to the motor controller 704. The motor outputs the desired torque, which is amplified by the reducer 703 and superimposed with the driver's torque to rotate the EPS system output shaft 705. The rack and pinion mechanism moves the rack, which in turn drives the wheels to rotate through the steering tie rod and steering knuckle arm, thus steering the vehicle.

[0056] Figure 8 This is a control flowchart of this embodiment. The system processes the steering wheel torque and angle detected by the torque angle sensor (TAS) and the CAN signal; it implements the basic EPS function and torque compensation function based on the processed signals; it performs stability compensation on the power assist output torque; it integrates the basic function torque; it then implements the EPS system protection function based on the input signal; it implements the advanced ADAS function according to the request from the host computer's Advanced Driving Assistance System (ADAS); it integrates the target motor torque; it processes the output signal, with the CAN signal entering the CAN bus and the torque signal entering the motor controller; and it incorporates the motor controller's functional logic to ultimately control the motor to output torque according to the torque signal, acting on the steering column of the EPS physical system.

[0057] The specific process involves first determining the integrated basic function torque, including: Step 1 processes the steering wheel torque and angle signals detected by the TAS sensor, the vehicle speed signal received from the CAN network, and the ADAS request signal. The input signals mainly include two types: CAN network signals and sensor signals. These signals enter the EPS function application layer as raw signal values, which are then transformed into actual values. Furthermore, for signals such as those from sensors and vehicle speed, their amplitude and rate of change should not be too large. Excessive abrupt changes are considered abnormal signals, and their amplitude and rate of change should be limited. The validity of the signals is then diagnosed and output.

[0058] The sensor signals mainly include: the TAS sensor detecting steering wheel torque and angle, the temperature sensor detecting motor temperature, and the motor angle sensor detecting the motor's electrical angle. The CAN network signals include: vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage sent by the motion domain controller (VMC). For the steering wheel torque and angle signals detected by the TAS sensor, self-learning functions for steering wheel center position angle and steering wheel torque are required. Center position angle self-learning: By recognizing the vehicle's straight-line state, and then learning the vehicle's straight-line center position based on information such as yaw rate, sensor torque, and wheel speed. Center position torque self-learning: When the steering wheel is in the center position and the driver's hands are not on the steering wheel, the system calculates the current torque bias value and corrects the steering wheel torque. Simultaneously, both of these require the use of non-volatile memory (NVM) in the BSW to update and save the bias values.

[0059] This step involves collecting multiple data points used to determine the integrated basic function torque.

[0060] Step 2: Based on the output signal from Step 1, implement the basic functions of EPS: power assist, damping, self-centering, and end protection; torque compensation functions: high-frequency compensation, hysteresis compensation, inertia compensation, shimmy compensation, wheel imbalance suppression, torque steering compensation, etc. As the mainstream carrier of L2 level assisted driving, the EPS system mainly achieves steering by having the driver turn the steering wheel. In addition to having the four basic functions, a high-performance EPS system should also pay attention to the driver's feel. That is, the torque feedback from the EPS system to the steering wheel should not be transmitted to the steering wheel through the steering column and then to the driver. Instead, the motor should compensate for the torque / angle that affects the driving feel, so that the driver can always maintain a smooth feeling when operating the steering wheel.

[0061] The power assist function is characterized by a gain coefficient that varies with vehicle speed. The value of the assist torque is determined by looking up the value in a calibrated mapping table based on vehicle speed and hand torque (unless otherwise specified, hand torque is the same as sensor torque). The damping function provides damping torque to the EPS, preventing driving safety issues caused by excessive steering and reducing overshoot when the steering wheel returns to center, thus preventing the steering wheel from rotating back and forth in the center position. The return-to-center function provides return-to-center torque to the steering wheel, automatically returning it to the center position when no steering force is applied. End-of-range protection prevents excessive steering speed from impacting the rack's end limit when the steering wheel reaches its left or right ends, thus shortening the EPS's mechanical lifespan. This function should also have a self-learning capability; that is, when the steering wheel reaches its end and the self-learning conditions are met, the NVM updates the end-of-range position offset value.

[0062] The high-frequency compensation function balances noise interference and road feel feedback. It calibrates the high-frequency and low-frequency boundary points and adjusts the system based on actual driving experience. This is achieved by using a frequency divider to divide the torque signal, with lower gain in the high-frequency band compared to the low-frequency band, improving system robustness. Hysteresis compensation overcomes torque lag caused by friction torque in the EPS system by providing a friction compensation torque. Different friction torque scaling factors are provided for steering wheel turning, return to center, and holding positions, improving driving feel. Inertia compensation compensates for system inertia, particularly the inertial torque generated by the motor rotor and accelerator, improving the response time and heaviness of the steering wheel during acceleration and deceleration. Shimmy compensation compensates for steering wheel vibration caused by mechanical disturbances at the end of the steering knuckle arm. This function utilizes a two-degree-of-freedom system composed of tires, rack, and steering knuckle arm components. Second-order vibrations at specific frequencies are transmitted to the steering wheel via the rack. Wheel imbalance suppression occurs when the front wheels are subjected to some degree of disturbance (e.g., front wheel imbalance). This interference can cause the driver to directly feel unpleasant vibrations in the steering wheel. This function reduces or resolves unnecessary vibrations in the steering wheel caused by interference from the vehicle's front wheels. Torque steering compensation detects whether torque steer is occurring and provides progressive torque compensation between when torque steer is present and when it is not, counteracting torque steer. This progressive compensation eliminates the abrupt change in the driver's perception of the module being enabled or disabled, providing a more natural steering feel.

[0063] Step 3: Apply stability compensation to the power assist output to improve system stability. Due to the presence of the power assist gain and the reducer, the output torque of the EPS motor amplifies the hand torque by tens or even hundreds of times. Excessive gain leads to a decrease in the stability of the control system. This function uses a second-order notch filter to improve the system stability margin. This compensation requires obtaining the true frequency domain information by sweeping the frequency of the actual vehicle's EPS.

[0064] Steps 2 and 3 involve determining which torques are involved when integrating the basic functional torques.

[0065] Step 4: Calculate the integrated basic function torque. The formula is as described in formula (1) above. Step 4 involves calculating the integrated basic function torque.

[0066] Step 5: Implement EPS system protection functions based on input signals, including motor stall protection and temperature protection. Stall protection occurs when the motor continues to output torque even at zero speed. This is used to address situations where the motor fails to start or stop due to excessive load, mechanical failure of the driven components, or bearing damage. When the motor is stalled, the power factor is extremely low, and the stall current can reach up to seven times the rated current; prolonged stalling can burn out the motor. This is achieved by detecting a stalled state and limiting the output of the stall torque and torque change rate accordingly. Temperature protection prevents the motor from overheating and extends its lifespan. A thermodynamic model is established to estimate the motor temperature. When the temperature reaches a threshold, the motor's assist capability is reduced; when the temperature drops to within the allowable range, the assist capability is restored. This step involves determining the torque protection coefficient using the motor data, thereby adjusting the integrated basic function torque. The system torque obtained in Step 6 below also needs to be adjusted using the torque protection coefficient.

[0067] Step 6: Based on the ADAS requests from the host computer, implement advanced ADAS functions: torque control, angle control, lane departure warning, etc. Torque control: Based on the torque requested by the host computer, control the EPS motor to output a specified torque to respond to the steering request from the ADAS controller. Angle control: Based on the angle requested by the host computer, control the EPS system to execute a specified angle to achieve the target steering wheel angle. Automatic parking and lane keeping: Perform angle control on the EPS based on the angle requested by the host computer. Lane departure warning: When the vehicle deviates from the current lane, the host computer sends a command to the lateral control system motor, and the motor vibrates to alert the driver. This step involves calculating the system torque.

[0068] Step 7: Integrate the target motor torque. The protection function torque output, ADAS torque output, and basic function integrated torque are integrated into a target motor torque and then output with a limited amplitude. In other words, when there is system torque, the torque protection coefficient is used to adjust the system torque, and the output is the target torque. When there is no system torque, the torque protection coefficient is used to adjust the integrated basic function torque, and the output is the target torque.

[0069] Step 8: Output signal processing, CAN signal packaging, and motor torque output. The integrated target motor torque is provided to the motor controller. The motor controller outputs a control voltage based on the target motor torque, and the drive motor outputs the actual rotor output torque, which is the target motor torque and acts on the EPS steering column. This step controls the steering column based on the target torque.

[0070] This embodiment also provides a steering column control device for performing the steering column control method described above. An example of this steering column control device can be found in the example of the steering column control method described above.

[0071] In one example, such as Figure 9 As shown, the steering column control device includes a Basic Software (BSW) layer and an Application Software (ASW) layer. The BSW layer includes an input function module that receives sensor signals and CAN signals and inputs them to the ASW, as well as an output function module that sends CAN signals to the motor controller. The ASW layer includes an input signal processing module and an output signal processing module, which process the ASW input and output signals respectively. A fault diagnosis module is used to diagnose the rationality and effectiveness of the control logic. A state machine module is used to jump between the power-on / off state and fault recovery state of the EPS controller. The basic function module includes three sets of function modules: basic power assist, stability control, and torque compensation, which respectively implement the corresponding control functions. The basic torque integration module integrates the basic function output torque. The protection function module protects the motor actuator. The ADAS advanced function module provides a function interface for ADAS. The target motor torque integration module integrates the above torques to obtain the input torque of the motor controller. Finally, the target motor torque is input to the motor controller to control the output of the specified torque AC voltage, and the CAN signal is output through the BSW to achieve high-performance EPS control.

[0072] The steering column control unit adopts the AUTOSAR architecture, with the BSW (Base Service Layer) as the basic service layer, providing essential functional services such as the operating system for ASW operation. The ASW layer is used to execute steering column control methods, including: The input and output signal processing module is used to process CAN signal packing and unpacking, receiving and sending, sensor signal parsing, target signal conversion, etc., and to provide steering wheel angle self-learning and torque self-learning for torque signals detected by the steering wheel TAS sensor, and to calibrate the center position of the steering wheel.

[0073] The fault diagnosis module provides diagnostic services for the entire EPS controller, including signal validity, logic rationality, fault occurrence, and EPS status.

[0074] The state machine module is the core module of the lateral control strategy in the chassis domain controller. It comprehensively judges the lateral system state information and assist limit based on the domain controller's own software and hardware diagnostics, the vehicle status, and the EPS status. The position, speed, and acceleration input of the steering wheel angle do not directly affect the output of this characteristic. The lateral system state of this module is used by other functional modules and the EPS as one of the conditions for activating functional modules. It also outputs an assist limit percentage to limit the motor's required assist value, and determines the interaction between the VMC domain controller and the vehicle and EPS states, and performs its own state transitions to limit the final motor's required assist value.

[0075] The basic functional modules include a basic power assist module, a stability control module, and a torque compensation module. The basic power assist module includes power assist, damping, self-centering, and end-of-line protection functions. The torque compensation module includes hysteresis compensation, inertia compensation, shimmy compensation, wheel imbalance suppression compensation, and torque steering compensation. The stability control module uses a second-order notch filter to improve system stability and enhance driving feel.

[0076] The basic torque integration module and the target motor torque integration module both realize torque superposition function. They respectively integrate the torque of the basic function linearly and integrate the torque of the target motor linearly. The integration process needs to consider torque direction, signal validity diagnosis and output limiting.

[0077] The protection module includes motor stall protection and temperature protection. Motor stall protection limits the motor torque output when the motor speed is 0 to prevent the motor from burning out. Temperature protection reduces the motor torque output when the motor temperature is too high and restores the torque output when the temperature drops.

[0078] The ADAS advanced function module includes angle control, torque control, lane keeping assist, automatic parking, and lane departure warning. Angle control and torque control, based on angle and torque requests input from the ADAS host computer, control the EPS to execute corresponding steering wheel angles and motor output torque. Lane keeping assist and automatic parking execute steering wheel angle outputs based on angle requests from the ADAS host computer. Lane departure warning vibrates the steering wheel to alert the driver when the vehicle deviates from its lane.

[0079] The motor controller module controls the motor to output a voltage with a specified torque based on the integrated target motor torque value to drive the motor.

[0080] This embodiment also provides a steering column control system, including a determining module for determining a torque protection coefficient based on motor data of the vehicle's motor; an adjusting module for adjusting the system torque using the torque protection coefficient to obtain a target torque when the system torque determined based on the vehicle's advanced driver assistance system is obtained; and for obtaining the integrated basic function torque of the vehicle and adjusting it using the torque protection coefficient when the system torque is not obtained, thereby obtaining the target torque; and a control module for controlling the steering column of the EPS according to the target torque. The steering column control system of this embodiment can execute the above-described steering column control method to control the steering column of the EPS system.

[0081] Figure 10 This is a system schematic diagram of this embodiment, including a torque sensor, a power steering motor, an EPS mechanical structure, and an ECU. The ECU executes the above-described steering column control method and controls the vehicle steering control system through the BSW layer.

[0082] This embodiment also provides a steering column control device, such as Figure 11 As shown, it includes a processor 111, a communication interface 112, a memory 113, and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114. Memory 113 is used to store computer programs; In one embodiment of this application, when the processor 111 executes the program stored in the memory 113, it implements the steering column control method provided in any of the foregoing method embodiments, including: determining a torque protection coefficient based on motor data of the vehicle motor; when a system torque determined according to the advanced driver assistance system of the vehicle is obtained, adjusting the system torque using the torque protection coefficient to obtain a target torque; when the system torque is not obtained, obtaining the integrated basic function torque of the vehicle, adjusting the integrated basic function torque using the torque protection coefficient to obtain the target torque; and controlling the steering column of the EPS according to the target torque.

[0083] This embodiment also provides a vehicle, including: a steering column control system, configured to determine a torque protection coefficient based on motor data of the vehicle's motor; when a system torque determined according to the vehicle's advanced driver assistance system is obtained, the system torque is adjusted using the torque protection coefficient to obtain a target torque; when the system torque is not obtained, the integrated basic function torque of the vehicle is obtained, and the integrated basic function torque is adjusted using the torque protection coefficient to obtain the target torque; and the steering column of the EPS is controlled according to the target torque; the steering column is used to steer the vehicle when controlled.

[0084] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the steering column control method provided in any of the foregoing method embodiments.

[0085] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0086] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0087] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0088] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A software system, characterized in that, include: The basic functional module is used to provide basic torque control for the vehicle and determine the integrated basic functional torque; Advanced driver assistance system module, used to determine the system torque of the advanced driver assistance system; The functional protection module is used to determine the torque protection coefficient based on the motor data of the automotive motor, and adjust the basic functional torque or the system torque using the torque protection coefficient to obtain the target torque; The motor controller module is used to control the steering column of the EPS according to the target torque; The basic functional modules include: a basic assist module for acquiring the low-frequency assist torque, high-frequency assist torque, self-aligning torque, end-protection torque, and damping torque of the vehicle; a torque compensation module for acquiring the hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, and torque steering compensation torque of the vehicle; and a stability control module for acquiring the system stability torque of the vehicle. The basic functional modules calculate the torques acquired by the basic assist module, the torque compensation module, and the stability control module according to a preset formula, and the result is used as the integrated basic functional torque. The basic functional module is also used to: determine the driving state of the vehicle; adjust the position and coefficient of the operation symbols in the preset formula and the torques used in low-frequency assist torque, high-frequency assist torque, self-aligning torque, end protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque according to the driving state; and calculate the integrated basic functional torque according to the adjusted preset formula. The basic functional module calculates the torques obtained by the basic assist module, the torque compensation module, and the stability control module according to a preset formula, and the result is used as the integrated basic functional torque. If one or more torques obtained by the basic assist module, the torque compensation module, and the stability control module are not applicable in the current environment, they will not participate in the calculation of the basic functional torque. For each torque in the preset formula, the calculation data used to calculate each torque is determined by querying the preset torque and data correspondence table. The calculation data is one or more of the following: steering wheel torque and angle signal, motor temperature, motor angle, vehicle speed, yaw rate, wheel speed, power on / off status, CAN voltage, and power supply voltage. If a torque is calculated using one piece of data, a functional relationship is established between the calculated data and the torque, and the value of the torque is calculated in a two-dimensional coordinate system. If a torque is calculated using at least two pieces of data, the at least two pieces of data are mapped to a multidimensional space, and the value of the torque is determined in the multidimensional space. If a torque is calculated using at least two pieces of computational data, then the at least two pieces of computational data are mapped into a multidimensional space. Determining the value of the torque in the multidimensional space includes: if a torque is calculated using two pieces of computational data, then the two pieces of computational data are mapped into a three-dimensional space, and the value in the third dimension is determined as the value of the torque.

2. The software system according to claim 1, characterized in that, The functional protection module is also used for: Obtain the motor speed and motor temperature of the automotive motor; When the motor speed or the motor temperature is abnormal, adjust the initial torque protection coefficient value to determine the torque protection coefficient.

3. The software system according to claim 1, characterized in that, The advanced driver assistance system of the vehicle is also used for: Determine the current functional mode of the advanced driver assistance system; The required torque under the current functional mode is determined as the system torque.

4. The software system according to claim 1, characterized in that, The software system also includes: An input / output signal processing module is used to obtain the computational data from the basic service layer; The basic power assist module, the torque compensation module, and the stability control module are used to determine the low-frequency power assist torque, high-frequency power assist torque, self-centering torque, end protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque of the vehicle based on the acquired steering wheel torque and angle signals, motor temperature, motor angle, vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage.

5. The software system according to claim 4, characterized in that, The basic assist module, the torque compensation module, and the stability control module are also used for: Determine the driving status of the vehicle; Under the current driving conditions, based on the steering wheel torque and angle signals, motor temperature, motor angle, vehicle speed, yaw rate, wheel speed, power-on / off status, CAN voltage, and power supply voltage, the following torque values ​​are determined to match the current driving conditions: low-frequency assist torque, high-frequency assist torque, self-centering torque, end-protection torque, damping torque, hysteresis compensation torque, inertia compensation torque, shimmy compensation torque, wheel imbalance suppression compensation torque, torque steering compensation torque, and system stability torque.

6. A steering column control system, characterized in that, include: The determination module is used to determine the torque protection coefficient based on the motor data of the automotive motor; An adjustment module is used to adjust the system torque determined by the advanced driver assistance system of the vehicle using the torque protection coefficient, or to adjust the integrated basic function torque of the vehicle to obtain a target torque; The control module is used to control the steering column of the EPS according to the target torque; The steering column control system further controls the steering column of the EPS through the software system described in any one of claims 1-5.

7. A steering column control method, characterized in that, The steering column control system described in claim 6 enables control of the steering column of the EPS.

8. A car, characterized in that, The steering column control system described in claim 6 enables control of the steering column of the vehicle's EPS.

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