Man-machine co-driving control method and system based on steering wheel angle control

Abstract

The invention provides a man-machine co-driving control method and system based on steering wheel angle control, and the method comprises the following steps: S1, matching a basic torque A according to a vehicle speed interval; in the step S2, an angle control request is sent to the EPS, the driver hand torque B transmitted by the EPS is obtained, and the torque limit C is adjusted in real time to be equal to the difference between the basic torque A and the driver hand torque B; in the step S3, the curve compensation torque D is obtained according to the curve radius and is superposed to the torque limit C; in the step S4, the vehicle lane changing requirement is recognized according to the vehicle direction changing lamp state or driver lane changing confirmation information, and a lane changing compensation torque F is provided in the vehicle lane changing process and superposed to the torque limit C; in the step S5, the comprehensive torque limit G is calculated and output to the EPS for execution. By optimizing a control strategy, man-machine co-driving of the system is friendly, and a transverse control function is not easy to exit after a driver intervenes.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and specifically, to a human-machine co-driving control method and system based on steering wheel angle control. Background Art

[0002] With the acceleration of the intelligentization process of automobiles, the configuration rate of advanced driver assistance systems (ADAS) has increased significantly. In particular, intelligent driving functions based on the L2 level (such as lane centering assist LKA, traffic jam assist TJA, integrated cruise assist ICA) have become the mainstream configurations of new models. These functions realize the coordinated control of lateral (lane keeping) and longitudinal (adaptive cruise) by sensing the environment and vehicle state, and theoretically allow the driver to only gently hold the steering wheel to achieve stable driving of the vehicle in the center of the lane lines.

[0003] The current core of the lateral assistance function relies on the linkage of visual perception and electronic steering control. The lane lines are recognized by a camera installed on the front windshield of the vehicle, and then a control request is sent to the electric power steering system (EPS) to maintain centering driving after comprehensively judging the vehicle body posture of the host vehicle. In recent years, the control request signal has changed from traditional torque control to angle control, but the human-machine co-driving of angle control has inherent deficiencies, with strong anti-sense, manifested as a very hard steering wheel. And the lateral control function is prone to exit after the driver intervenes and overrides. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a human-machine co-driving control method and system based on steering wheel angle control, aiming to optimize the control strategy, making the system friendly for human-machine co-driving and the lateral control function not easy to exit after the driver intervenes.

[0005] To achieve the above-mentioned invention purpose, the present invention adopts the following technical solutions:

[0006] According to the first aspect of the present invention, a human-machine co-driving control method based on steering wheel angle control is provided, including the following steps:

[0007] In step S1, the vehicle speed information is obtained in real time, and the vehicle speed range in which the vehicle is located is identified. According to the vehicle speed range and the real-time vehicle speed, the basic torque A is matched; the preset basic torque A increases with the increase of the vehicle speed range; the matching method of the basic torque A is:

[0008] For the vehicle speed greater than or equal to 0 km / h and less than 60 km / h, set the basic torque A = 1.5 + V * 0.01;

[0009] For the vehicle speed greater than or equal to 60 km / h and less than 90 km / h, set the basic torque A = 2 + V * 0.006;

[0010] When the vehicle speed is greater than or equal to 90 km / h, set the basic torque limit A = 2.5 + V * 0.003;

[0011] V is the real-time vehicle speed;

[0012] In step S2, send an angle control request to the EPS, obtain the driver's hand torque B transmitted by the EPS, perform Kalman filtering on the driver's hand torque, and perform filtering with a 12-pole non-cascaded Butterworth filter with a cut-off frequency of 10 Hz; adjust the torque limit C in real time to be equal to the basic torque A minus the driver's hand torque B;

[0013] In step S3, obtain the curve compensation torque D according to the curve radius and superimpose it on the torque limit C; the curve radius identification method is:

[0014] Measure the rotation rate ω of the vehicle around the vertical axis through an inertial measurement unit, obtain the vehicle longitudinal speed v1 through a wheel speedometer or GPS speed information, and calculate the radius R1 = v1 / ω by combining the data;

[0015] Use an edge detection algorithm or a lane line detection algorithm to identify the road boundary or center line, fit the detected pixel points into a smooth curve, calculate the curvature κ of each point on the smooth curve using the curve fitting equation, and calculate the fitting radius R2 = 1 / |κ|;

[0016] Calculate the curve radius as: R = √(R1 * R2);

[0017] In step S4, identify the vehicle lane change demand through the vehicle turn signal status or the driver's lane change confirmation information, and provide a lane change compensation torque F and superimpose it on the torque limit C during the vehicle lane change; when any of the following scenarios is recognized, it is determined that there is a vehicle lane change demand: the offset of the vehicle center line relative to the lane center line is greater than 15% of the lane width and continues to increase within a preset time range; the included angle between the vehicle heading angle and the lane direction is greater than 5°, and the duration exceeds the preset time range; the vehicle lateral acceleration is greater than or equal to 0.3 m / s² and less than or equal to 0.6 m / s²; the left turn signal or the right turn signal is in the on state;

[0018] In step S5, perform the calculation of the comprehensive torque limit G and output it to the EPS for execution. The calculation formula for the comprehensive torque limit G is: comprehensive torque limit G = torque limit C + curve compensation torque D + lane change compensation torque F; the EPS uses the comprehensive torque limit G as the torque upper limit to drive the steering motor to execute the requested angle.

[0019] Preferably, in step S1, when the vehicle speed is greater than or equal to 0 km / h and less than 60 km / h, the basic torque A is set to 2.0 N*m; when the vehicle speed is greater than or equal to 60 km / h and less than 90 km / h, the basic torque A is set to 2.5 N*m; when the vehicle speed is greater than or equal to 90 km / h, the limit value of the basic torque A is set to 3.0 N*m.

[0020] Preferably, in step S3, when the curve radius is less than or equal to 100 m, the preset compensation torque D is 1.5 N*m; when the curve radius is greater than 100 m and less than or equal to 500 m, the preset compensation torque D is 1.0 N*m; when the curve radius is greater than 500 m and less than or equal to 1500 m, the preset compensation torque D is 0.8 N*m.

[0021] Preferably, in step S4, when it is recognized that the vehicle is in the process of changing lanes through the vehicle turn signal state or the driver's lane change confirmation information, the lane change compensation torque F is a fixed value of 1 N*m and is superimposed on the torque limit.

[0022] According to the second aspect of the present invention, there is provided a human-machine co-driving control system based on the steering wheel angle control, which is used to execute the above-mentioned human-machine co-driving control method based on the steering wheel angle control, and includes:

[0023] An ADAS control module, which can send an angle control request to the EPS;

[0024] A basic torque acquisition module, which is used to match the corresponding basic torque A according to the vehicle speed;

[0025] A torque weakening module, which is used to obtain the driver's hand torque B transmitted by the EPS, and obtain the torque limit C according to the basic torque A and the driver's hand torque B;

[0026] A curve compensation module, which is used to obtain the curve compensation torque D according to the curve radius;

[0027] A lane change compensation module, which is used to identify the vehicle lane change demand, and provide the lane change compensation torque F and superimpose it on the torque limit during the vehicle lane change process;

[0028] A torque limit output module, which calculates and outputs the comprehensive torque limit G. The calculation formula of the comprehensive torque limit G is: comprehensive torque limit G = torque limit C + curve compensation torque D + lane change compensation torque F;

[0029] The EPS, which can execute the angle control according to the comprehensive torque limit G.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. By considering the driver's hand torque information during the angle control process, the present invention can carry out dynamic countermeasure weakening in real time, respond to driver intervention in real time, and solve the problem of the traditional angle control steering wheel being rigid.

[0032] 2. Through the torque compensation steps in special scenarios, the present invention can achieve scenario adaptive compensation. Relying on the compensation mechanisms for the curve radius and lane change state, it ensures control stability in complex scenarios, realizes human-machine collaborative optimization, and balances the system control requirements and the driver's operation experience by outputting comprehensive torque limits, thereby improving the usability of the intelligent driving function. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Other features, objectives, and advantages of the present invention will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings:

[0034] Figure 1 It is a schematic flowchart of the method described in Embodiment 1;

[0035] Figure 2 It is a schematic structural diagram of the system described in Embodiment 2. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application to be protected, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.

[0038] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, all directional indications (such as up, down, left, right, front, back, bottom...) in the present application are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0039] Embodiment 1

[0040] This embodiment provides a human-machine co-driving control method based on steering wheel angle control. Aiming at the defects existing in the human-machine co-driving of the lateral control function angle control, such as strong confrontation, hard steering wheel, and easy exit of the lateral control function after the driver intervenes, through the optimization of the control strategy, the system is made friendly for human-machine co-driving, and the lateral control function is not easy to exit after the driver intervenes and overrides.

[0041] The method provided in this embodiment involves the interaction signals between the ADAS (Advanced Driver Assistance System) control module and the EPS (Electronic Power Steering System), including the angle request signal, the driver's hand torque, and the execution angle torque limit. Among them, the angle request signal represents the need to control the steering wheel to turn left or right; the driver's hand torque represents the torque generated by the driver holding the steering wheel; the execution angle torque limit is the maximum torque limit that can be used during the EPS execution angle process.

[0042] As Figure 1 shown, it includes the following steps:

[0043] In step S1, the corresponding basic torque A is matched in real time according to the vehicle speed. In this embodiment, the vehicle speed information is obtained in real time, and after identifying the vehicle speed range it is in, the basic torque A corresponding to the vehicle speed range is matched. Each vehicle speed range is preset with a corresponding basic torque A, and the basic torque A increases as the vehicle speed range increases. Specifically, when the vehicle speed is greater than or equal to 0 km / h and less than 60 km / h, the basic torque A is set to 2.0 N*m; when the vehicle speed is greater than or equal to 60 km / h and less than 90 km / h, the basic torque A is set to 2.5 N*m; when the vehicle speed is greater than or equal to 90 km / h, the basic torque limit A is set to 3.0 N*m.

[0044] In other alternative embodiments, the determination method of the basic torque A can also be: obtain the vehicle speed information in real time, and after identifying the vehicle speed range it is in, match the basic torque A corresponding to the vehicle speed range according to the vehicle speed range and the real-time vehicle speed. The matching method is:

[0045] When the vehicle speed is greater than or equal to 0 km / h and less than 60 km / h, set the basic torque A = 1.5 + V * 0.01;

[0046] When the vehicle speed is greater than or equal to 60 km / h and less than 90 km / h, set the basic torque A = 2 + V * 0.006;

[0047] When the vehicle speed is greater than or equal to 90 km / h, set the basic torque limit A = 2.5 + V * 0.003;

[0048] Here, V is the real-time vehicle speed.

[0049] In step S2, an angle control request is sent to the EPS, and the driver's hand torque B is obtained and torque weakening is performed based on it to obtain the torque limit C. Specifically, the driver's hand torque B transmitted by the EPS is obtained, and the torque limit C is adjusted in real time to be equal to the base torque A minus the driver's hand torque B, thereby reducing the torque during the EPS angle control process, and at the same time, the counteracting feeling that the driver can perceive also decreases. When the base torque A remains unchanged and the driver's hand torque B increases, the system output torque limit C decreases, forming an effect of one increasing while the other decreasing, significantly reducing the human-machine steering counteracting feeling; at the same time, the base torque A can play an upper limit role to ensure that the system always maintains the basic control ability.

[0050] Furthermore, when obtaining the driver's hand torque B transmitted by the EPS, since the driver's hand force obtained by the EPS from the sensor often has noise interference, such as road surface bumps, in order to calculate the human-machine co-driving torque more robustly, in step S2 of this embodiment, a Kalman filter is also performed on the driver's hand torque, and a 12-pole non-order Butterworth filter is used for filtering, with a cut-off frequency of 10 Hz.

[0051] In step S3, the corner compensation torque D is obtained according to the corner radius and is superimposed on the torque limit. This step can solve the defect that when the driver holds the steering wheel, the torque limit C is too small and may not meet the cornering performance. Specifically, in this embodiment, corresponding compensation torques D are preset for different corner radius ranges. In a preferred embodiment, when the corner radius is less than or equal to 100 m, the preset compensation torque D is 1.5 N*m; when the corner radius is greater than 100 m and less than or equal to 500 m, the preset compensation torque D is 1.0 N*m; when the corner radius is greater than 500 m and less than or equal to 1500 m, the preset compensation torque D is 0.8 N*m.

[0052] Furthermore, in step S3 of this embodiment, the corner radius is also identified, and the identification method is as follows:

[0053] The rotation rate ω of the vehicle around the vertical axis is directly measured by an in-vehicle sensor (such as using an inertial measurement unit, IMU), and the longitudinal speed v1 of the vehicle is obtained through a wheel speedometer or GPS speed information. The radius R1 is calculated by combining the data as R1 = v1 / ω;

[0054] The edge detection algorithm or lane line detection algorithm is used to identify the road boundary or center line, and the detected pixel points are fitted into a smooth curve (such as a polynomial curve, B-spline curve, or explicit circular arc). The curvature κ of each point on the curve is calculated using the curve fitting equation, and the identified curve fitting radius R2 = 1 / |κ| is calculated;

[0055] The calculated curve radius is: R = √(R1 * R2). In step S4, the vehicle lane change requirement is identified, and a lane change compensation torque F is provided during the vehicle lane change process and superimposed on the torque limit. When the vehicle is in the process of changing lanes, whether it is the driver turning on the turn signal to change lanes or the driver confirming the lane change, in the case of non-curved roads, there is no additional torque compensation, so there will be a torque shortage during the lane change process. This step considers and can effectively solve the torque compensation requirement in this scenario, judges the lane change process, and provides lane change torque compensation. Specifically, the lane change compensation torque F in this embodiment is default to 0 N*m. When it is recognized that the vehicle is in the process of changing lanes through the vehicle turn signal state or the driver's lane change confirmation information, the lane change compensation torque F is a fixed value of 1 N*m and is superimposed on the torque limit.

[0056] Further, when this embodiment recognizes any of the following scenarios, it is determined that there is a vehicle lane change requirement:

[0057] Monitoring lateral displacement: It is recognized that the offset of the vehicle center line relative to the lane center line is greater than 15% of the lane width and continues to increase within the preset time range;

[0058] Monitoring yaw angle change: The angle between the vehicle heading angle and the lane direction is greater than 5°, and the duration exceeds the preset time range;

[0059] Lateral acceleration monitoring: The vehicle lateral acceleration is greater than or equal to 0.3 m / s² and less than or equal to 0.6 m / s²;

[0060] Turn signal monitoring: The left turn signal or the right turn signal is in the on state.

[0061] In step S5, the comprehensive torque limit G is calculated and output to the EPS for execution. In this embodiment, the calculation formula for the comprehensive torque limit G is: Comprehensive torque limit G = Torque limit C + Curve compensation torque D + Lane change compensation torque F. The EPS takes the calculated comprehensive torque limit G as the torque upper limit, drives the steering motor to execute the angle requested by the ADAS control module, and finally achieves an excellent human-machine co-driving experience.

[0062] This solution optimizes the human-machine co-driving experience. This system is based on the current vehicle's intelligent driving controller. For software algorithm updates, it does not increase the hardware cost and improves the user experience of intelligent driving assistance functions. Specifically, this embodiment can achieve the following beneficial effects: First, this method can dynamically counteract weakening, respond to driver intervention in real time, and solve the problem of the traditional angle-controlled steering wheel being stiff; Second, this method can achieve scenario adaptive compensation, rely on the compensation mechanism for the curve radius and lane change state, ensure control stability in complex scenarios, and can achieve human-machine collaborative optimization, balance the system control requirements and the driver's operation experience by outputting the comprehensive torque limit, and improve the usability of the intelligent driving function.

[0063] Embodiment 2

[0064] This embodiment provides a human-machine co-driving control system based on steering wheel angle control. Through the cooperation of each module in the system, a human-machine co-driving control method described in Embodiment 1 can be realized.

[0065] As Figure 2 shown, the system provided in this embodiment includes: an ADAS control module capable of sending an angle control request to the EPS; a basic torque acquisition module for matching a corresponding basic torque A according to the vehicle speed; a torque weakening module for acquiring the driver's hand torque B transmitted by the EPS and obtaining a torque limit C based on the basic torque A and the driver's hand torque B; a curve compensation module for obtaining a curve compensation torque D according to the curve radius; a lane change compensation module for identifying the vehicle's judgment requirements and providing a lane change compensation torque F and superimposing it on the torque limit during the vehicle lane change process; a torque limit output module for calculating and outputting a comprehensive torque limit G. The calculation formula of the comprehensive torque limit G is: comprehensive torque limit G = torque limit C + curve compensation torque D + lane change compensation torque F; the EPS can execute angle control according to the comprehensive torque limit G.

[0066] It should be noted that the explanations of various implementation manners and beneficial effects of the above-mentioned method in Embodiment 1 also apply to this embodiment. To avoid redundancy, they will not be elaborated in detail here.

[0067] The specific embodiments of the present invention have been described above. Through the above description, relevant staff can make various changes and modifications completely within the scope not deviating from the technical idea of this invention.

Claims

1. A human-machine co-driving control method based on steering wheel angle control, characterized in that, It includes the following steps: In step S1, obtain the vehicle speed information in real time, identify the vehicle speed range it is in, and match the basic torque A according to the vehicle speed range and the real-time vehicle speed; the preset basic torque A increases as the vehicle speed range increases; the matching method of the basic torque A is as follows: When the vehicle speed is greater than or equal to 0 km / h and less than 60 km / h, set the basic torque A = 1.5 + V * 0.01; When the vehicle speed is greater than or equal to 60 km / h and less than 90 km / h, set the basic torque A = 2 + V * 0.006; When the vehicle speed is greater than or equal to 90 km / h, set the basic torque limit A = 2.5 + V * 0.003; V is the real-time vehicle speed; In step S2, send an angle control request to the EPS, obtain the driver's hand torque B transmitted by the EPS, perform Kalman filtering on the driver's hand torque, and perform filtering with a 12-pole non-order Butterworth filter with a cut-off frequency of 10 Hz; adjust the torque limit C in real time to be equal to the basic torque A minus the driver's hand torque B; In step S3, obtain the corner compensation torque D according to the corner radius and superimpose it on the torque limit C; the identification method of the corner radius is as follows: Measure the rotation rate ω of the vehicle around the vertical axis through the inertial measurement unit, obtain the vehicle longitudinal speed v1 through the wheel speedometer or GPS speed information, and calculate the radius R1 = v1 / ω by combining the data; Use the edge detection algorithm or the lane line detection algorithm to identify the road boundary or the center line, fit the detected pixel points into a smooth curve, calculate the curvature κ of each point on the smooth curve using the curve fitting equation, and calculate the fitting radius R2 = 1 / |κ|; Calculate the corner radius as: R = √(R1 * R2); In step S4, identify the vehicle lane change requirement through the vehicle turn signal status or the driver's lane change confirmation information, and provide the lane change compensation torque F during the vehicle lane change process and superimpose it on the torque limit C; when any of the following scenarios is recognized, it is determined that there is a vehicle lane change requirement: it is recognized that the offset of the vehicle center line relative to the lane center line is greater than 15% of the lane width and continues to increase within the preset time range; The included angle between the vehicle heading angle and the lane direction is greater than 5°, and the duration exceeds the preset time range; the vehicle lateral acceleration is greater than or equal to 0.3 m / s² and less than or equal to 0.6 m / s²; the left turn signal or the right turn signal is in the on state; In step S5, perform the calculation of the comprehensive torque limit G and output it to the EPS for execution. The calculation formula of the comprehensive torque limit G is: comprehensive torque limit G = torque limit C + corner compensation torque D + lane change compensation torque F; The EPS uses the comprehensive torque limit G as the torque upper limit and drives the steering motor to execute the requested angle.

2. The human-machine co-driving control method based on steering wheel angle control according to claim 1, wherein In step S1, when the vehicle speed is greater than or equal to 0 km / h and less than 60 km / h, set the basic torque A to 2.0 N*m, when the vehicle speed is greater than or equal to 60 km / h and less than 90 km / h, set the basic torque A to 2.5 N*m, and when the vehicle speed is greater than or equal to 90 km / h, set the basic torque limit A to 3.ON*m.

3. A human-machine co-driving control method based on steering wheel angle control according to claim 1, characterized in that, In step S3, when the curve radius is less than or equal to 100 m, the preset compensation torque D is 1.5 N*m; when the curve radius is greater than 100 m and less than or equal to 500 m, the preset compensation torque D is 1.0 N*m; when the curve radius is greater than 500 m and less than or equal to 1500 m, the preset compensation torque D is 0.8 N*m.

4. A human-machine co-driving control method based on steering wheel angle control according to claim 1, characterized in that, In step S4, when it is recognized that the vehicle is in the process of changing lanes through the vehicle turn signal state or the driver's lane change confirmation information, the lane change compensation torque F is a fixed value of 1 N*m and is superimposed on the torque limit.

5. A human-machine co-driving control system based on steering wheel angle control, characterized in that, For implementing the human-machine co-driving control method based on the steering wheel angle control according to any one of claims 1-4, including: An ADAS control module capable of sending an angle control request to the EPS; A basic torque acquisition module for matching the corresponding basic torque A according to the vehicle speed; A torque weakening module for obtaining the driver's hand torque B transmitted by the EPS and obtaining the torque limit C according to the basic torque A and the driver's hand torque B; A curve compensation module for obtaining the curve compensation torque D according to the curve radius; A lane change compensation module for identifying the vehicle lane change requirement and providing the lane change compensation torque F and superimposing it on the torque limit during the vehicle lane change process; A torque limit output module for calculating and outputting the comprehensive torque limit G, and the calculation formula of the comprehensive torque limit G is: comprehensive torque limit G = torque limit C + curve compensation torque D + lane change compensation torque F; An EPS capable of performing angle control according to the comprehensive torque limit G.

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