Steering wheel hand-off detection method, detection device and vehicle

Abstract

The application provides a steering wheel hand-off detection method, a detection device and a vehicle, and belongs to the technical field of steering wheel hand-off detection. The steering wheel hand-off detection method comprises the following steps: obtaining a system return torque value of a steering wheel by learning after power assistance of a steering system of a vehicle; detecting an actual return torque value of the steering wheel in real time; generating a hand-off state signal according to the system return torque value and the actual return torque value; and judging whether the steering wheel is in a hand-off state according to a requested steering angle of the steering wheel, a current steering angle of the steering wheel, the hand-off state signal and the actual return torque value. The steering wheel hand-off detection method can meet the accuracy requirement of function hand-off detection of automatic auxiliary driving.

Description

Technical Field

[0001] This invention relates to the field of steering wheel hands-off detection technology, and in particular to a steering wheel hands-off detection method, detection device, and vehicle. Background Technology

[0002] When a vehicle's intelligent driving function is activated, it is usually necessary to determine the driver's intention to take over based on the steering wheel hands-off detection results. Currently, the commonly used hands-off detection method determines whether the driver is in a hands-off state based on the magnitude of the torque applied to the steering wheel; however, this detection method is easily affected by external factors.

[0003] In other words, the current method of hands-off detection based on the steering system has a high false alarm rate and low detection accuracy. This will affect the automatic driving assistance functions developed based on the steering system, making them unable to pass ECE regulations (United Nations Economic Commission for Europe Automotive Regulations) and unable to meet the accuracy requirements for hands-off detection in automatic driving assistance functions. Summary of the Invention

[0004] One objective of the first aspect of this invention is to provide a steering wheel hands-off detection method that can meet the accuracy requirements of hands-off detection for automatic driving assistance functions.

[0005] A second aspect of the present invention is to provide a steering wheel hands-off detection device for implementing the above-described steering wheel hands-off detection method.

[0006] A third aspect of the present invention is to provide a vehicle including the above-described steering wheel hands-off detection device.

[0007] Specifically, the present invention provides a method for detecting steering wheel removal from hands, comprising:

[0008] After the vehicle's steering system is powered by electricity, the system learns and obtains the steering wheel's return torque value.

[0009] Real-time detection of the actual return torque value of the steering wheel;

[0010] A release status signal is generated based on the system return torque value and the actual return torque value;

[0011] The system determines whether the steering wheel is in a hands-free state based on the requested steering angle, the current steering angle, the hands-free state signal, and the actual return torque value.

[0012] Optionally, the steps for learning the system return torque value of the steering wheel include:

[0013] The first return torque when the steering wheel is turned to the left by a preset angle and the second return torque when the steering wheel is turned to the right by the preset angle are detected;

[0014] Based on the first positive torque and the second positive torque, the corresponding first learning torque and second learning torque are learned, and the deviation between the first learning torque and the second learning torque is controlled to be less than the deviation threshold.

[0015] The system return torque value is obtained based on the first learning torque and the second learning torque.

[0016] Optionally, the step of deriving the system return torque value based on the first learning torque and the second learning torque includes:

[0017] Calculate the average of the absolute values ​​of the first learning torque and the second learning torque;

[0018] When the average value is greater than the return torque threshold, the return torque threshold is used as the return torque value of the system.

[0019] When the average value is less than or equal to the return torque threshold, the average value is used as the system return torque value.

[0020] Optionally, the step of generating a release status signal based on the system return torque value and the actual return torque value includes:

[0021] The first number of times the absolute difference between the system's return torque value and the actual return torque value is greater than the torque calibration value;

[0022] When the first number of times reaches a first threshold, a timing is started, and when the timing time reaches a first time threshold, a release signal is generated;

[0023] The second number of times the absolute value of the difference between the system's return torque value and the actual return torque value is less than or equal to the torque calibration value;

[0024] When the second number of times reaches the second threshold, a timing is started, and when the timing time reaches the second time threshold, an unreleased signal is generated, wherein the first threshold is greater than the second threshold.

[0025] Optionally, the step of determining whether the steering wheel is in a hands-free state based on the requested steering wheel angle, the current steering wheel angle, the hands-free state signal, and the actual return torque value includes:

[0026] The steering wheel is considered to be in a hands-free state when the following conditions are met simultaneously:

[0027] The requested steering angle of the steering wheel is greater than or equal to the current steering angle of the steering wheel;

[0028] The release signal was received;

[0029] Within a third preset time period after the lateral control function of the vehicle's autonomous driving module is activated, the third number of times the actual return torque value is greater than the return torque threshold is less than or equal to the third threshold.

[0030] Optionally, the step of determining whether the steering wheel is in a hands-free state based on the requested steering wheel angle, the current steering wheel angle, the hands-free state signal, and the actual return torque value further includes:

[0031] The steering wheel is considered to be in a hands-on state when one of the following conditions is met:

[0032] The requested steering angle of the steering wheel is less than the current steering angle of the steering wheel;

[0033] The signal indicating that the hand had not been released was received;

[0034] During the third preset time period when the lateral control function of the vehicle's autonomous driving module is activated, the third number of times the actual return torque value is greater than the return torque threshold is greater than the third threshold.

[0035] Optionally, after determining whether the steering wheel is in a hands-free state based on the requested steering wheel angle, the current steering wheel angle, the hands-free state signal, and the actual return torque value, the method further includes:

[0036] A hands-off alarm is triggered when the steering wheel is in a hands-off state.

[0037] The hands-off alarm will stop when the steering wheel is in the hands-on state.

[0038] In particular, the present invention also provides a steering wheel hands-off detection device, comprising:

[0039] A torque detection unit is used to detect the actual return torque value of the steering wheel in real time.

[0040] The steering control unit is used to learn the system return torque value of the steering wheel after the vehicle's steering system is first powered on, and to generate a hands-off state signal based on the system return torque value and the actual return torque value.

[0041] The automatic driving control module is used to determine whether the steering wheel is in a hands-free state based on the requested steering angle of the steering wheel, the current steering angle of the steering wheel, the hands-free state signal, and the actual return torque value.

[0042] Optionally, the steering wheel hands-off detection device also includes:

[0043] The display module, connected to the autonomous driving control module, is used to issue a hands-off alarm when it is determined that the steering wheel is in a hands-off state.

[0044] In particular, the present invention also provides a vehicle including the above-described steering wheel hands-off detection device.

[0045] According to an embodiment of the present invention, a method for detecting whether a steering wheel is off-hand is provided. First, a hand-off state signal is generated based on the system return torque value and the actual return torque value, which is a preliminary detection of whether the steering wheel is off-hand. Based on this hand-off state signal, the requested steering angle, the current steering angle, and the actual return torque value of the steering wheel are combined to jointly determine whether the steering wheel is in a hand-off state, thereby improving the accuracy of determining whether the steering wheel is off-hand and meeting the accuracy requirements of hand-off detection for automatic assisted driving functions.

[0046] According to one embodiment of the present invention, the system return torque value is obtained through learning. This torque value is taken as the average of the first learned torque corresponding to left turn and the first learned torque corresponding to right turn, so that the return torque value corresponding to left turn and right turn of the steering wheel is the same, thereby making the assist torque provided by the vehicle the same when turning left and right, so that the user feels the same value of assistance when turning left and right, which is beneficial to improving the user experience.

[0047] Furthermore, by setting the return torque threshold, the learned return torque value can be prevented from exceeding the normal range, which would lead to inaccurate learning values ​​and help ensure the accuracy of subsequent steering wheel release judgment.

[0048] According to one embodiment of the present invention, the accuracy of release detection can be increased by comparing and counting the system return torque value with the actual return torque value.

[0049] According to one embodiment of the present invention, based on the steering control unit's determination that the steering wheel is in a hands-free state, the relationship between the requested steering angle and the current steering angle of the steering wheel is considered, as well as the condition that the actual return torque value is greater than the return torque threshold number of times the lateral control function of the automatic driving module is activated within a certain period of time, which can more accurately determine whether the steering wheel is in a hands-free state.

[0050] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0051] The following sections will describe some specific embodiments of the invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0052] Figure 1This is a flowchart of a steering wheel hands-off detection method according to an embodiment of the present invention;

[0053] Figure 2 This is a connection block diagram of a steering wheel hands-off detection device according to an embodiment of the present invention;

[0054] Figure 3 This is a flowchart of a steering wheel hands-off detection method according to another embodiment of the present invention;

[0055] Figure 4 This is a connection block diagram of a steering wheel hands-off detection device according to another embodiment of the present invention.

[0056] Figure label:

[0057] 10 - Torque detection unit, 20 - Steering control unit, 30 - Automatic driving control module, 40 - Display module. Detailed Implementation

[0058] Figure 1 This is a flowchart of a steering wheel hands-off detection method according to an embodiment of the present invention. Figure 2 This is a connection block diagram of a steering wheel hands-off detection device according to an embodiment of the present invention. Figure 1 As shown, in one embodiment, the steering wheel hands-off detection method includes:

[0059] Step S100: After the vehicle's steering system is powered on, the system return torque value of the steering wheel is obtained through learning.

[0060] Step S200: Real-time detection of the actual return torque value of the steering wheel;

[0061] Step S300: Generate a release status signal based on the system return torque value and the actual return torque value;

[0062] Step S400: Determine whether the steering wheel is in a hands-free state based on the steering wheel's requested steering angle, the current steering wheel angle, the hands-free state signal, and the actual return torque value.

[0063] like Figure 2 As shown, the actual return torque value in step S200 can be measured by the torque detection unit 10. For example, the torque detection unit 10 can be a torque sensor installed at the steering wheel. Steps S100 and S300 can be implemented by the steering control unit 20, and step S400 can be implemented by the automatic driving control module 30.

[0064] The steering wheel hands-off detection method in this embodiment first generates a hands-off status signal based on the system return torque value and the actual return torque value, which is a preliminary detection of whether the steering wheel is off the hands. Based on this hands-off status signal, the requested steering angle, the current steering angle, and the actual return torque value of the steering wheel are combined to jointly determine whether the steering wheel is in a hands-off state, thereby improving the accuracy of determining whether the steering wheel is off the hands and meeting the accuracy requirements of hands-off detection for automatic assisted driving functions.

[0065] Figure 3 This is a flowchart of a steering wheel hands-off detection method according to another embodiment of the present invention. Figure 3 As shown, in one embodiment, step S100 includes:

[0066] Step S110: After the vehicle's steering system is powered on, detect the first return torque when the steering wheel is turned to the left at a preset angle and the second return torque when the steering wheel is turned to the right at a preset angle.

[0067] Step S120: Based on the first return torque and the second return torque, the corresponding first learning torque and second learning torque are learned, and the deviation between the first learning torque and the second learning torque is controlled to be less than the deviation threshold.

[0068] Step S130: The system return torque value is obtained based on the first learning torque and the second learning torque.

[0069] The first and second return torques in step S110 correspond to left and right turns of the steering wheel, respectively, and are therefore positive and negative. The preset angle can be set to any value between 5 and 12°, such as 5°, 10° or 12°. Preferred, the preset angle is 10°.

[0070] In step S120, the first learning torque and the second learning torque correspond to the first return torque and the second return torque, respectively, and therefore have positive and negative values. Let the first learning torque be a and the second learning torque be b, where a and b are opposite in sign. The deviation between the first learning torque and the second learning torque can be expressed as a+b or |a|-|b|. The deviation threshold here is set in advance, for example, 0.25 NM. Of course, the deviation threshold can be adjusted accordingly according to the learning accuracy requirements, and can be larger or smaller, without any restrictions here.

[0071] In a further embodiment, step S130 includes:

[0072] Calculate the absolute value of the first learning torque and the average of the absolute values ​​of the second learning torque;

[0073] When the mean value is greater than the return torque threshold, the return torque threshold is used as the system return torque value;

[0074] When the mean value is less than or equal to the return torque threshold, the mean value is used as the system return torque value.

[0075] The self-alignment torque threshold here can be set empirically, for example, to 0.375 NM. The self-alignment torque threshold indicates that in most cases, the self-alignment torque will not exceed this value. When it exceeds the threshold, it means the learned torque value is not very accurate. Therefore, once the absolute value of the first learned torque and the average of the absolute values ​​of the second learned torque exceed the self-alignment torque threshold, the self-alignment torque threshold is directly assigned to the system as the self-alignment torque value. The above process can be expressed as:

[0076] When (|a|+|b|) / 2>A0, A=A0;

[0077] When (|a|+|b|) / 2≤A0, A=(|a|+|b|) / 2.

[0078] Where a is the first learning torque, b is the second learning torque, A0 is the return torque threshold, and A is the system return torque.

[0079] Since a is a positive number and b is a negative number, the above (|a|+|b|) / 2 can also be expressed as (a+b) / 2.

[0080] This embodiment obtains the system's self-centering torque value through learning. This torque value is taken as the average of the first learned torque corresponding to left turn and the first learned torque corresponding to right turn, so that the self-centering torque value corresponding to left turn and right turn of the steering wheel is the same. This makes the assist torque provided by the vehicle the same when turning left and right, so that the user feels the same amount of assistance when turning left and right, which is beneficial to improving the user experience.

[0081] Furthermore, by setting the return torque threshold, the learned return torque value can be prevented from exceeding the normal range, which would lead to inaccurate learning values ​​and help ensure the accuracy of subsequent steering wheel release judgment.

[0082] like Figure 3 As shown, in one embodiment, step S300 includes:

[0083] Step S310: The first number of times the absolute difference between the system return torque value and the actual return torque value is greater than the torque calibration value;

[0084] Step S320: When the first number of times reaches the first threshold, start timing, and when the timing time reaches the first time threshold, generate a release signal;

[0085] Step S330: The second number of times the absolute difference between the system return torque value and the actual return torque value is less than or equal to the torque calibration value;

[0086] Step S340: When the second number of times reaches the second threshold, a timing is started, and when the timing time reaches the second time threshold, an unreleased signal is generated, where the first threshold is greater than the second threshold.

[0087] The torque calibration values ​​mentioned above are generally calibrated by the manufacturer. The first and second thresholds can be set to 15 and 4 respectively, and the first and second time thresholds can be set to 2 seconds. The detection period for the first and second counts can be defined according to the signal transmission period.

[0088] This embodiment increases the accuracy of release detection by comparing and counting the system's return torque value with the actual return torque value.

[0089] In one embodiment, step S400 includes:

[0090] The steering wheel is considered to be in a hands-free state when the following conditions are met simultaneously:

[0091] The requested steering wheel angle is greater than or equal to the current steering wheel angle;

[0092] Received release signal;

[0093] Within the third preset time period after the lateral control function of the vehicle's autonomous driving module is activated, the third number of times the actual return torque value is greater than the return torque threshold is less than or equal to the third threshold.

[0094] The steering wheel is considered to be in a "hands-on" state when one of the following conditions is met:

[0095] The requested steering wheel angle is less than the current steering wheel angle;

[0096] Received a signal that the item was not released;

[0097] Within the third preset time period after the lateral control function of the vehicle's autonomous driving module is activated, the actual return torque value is greater than the return torque threshold for the third time.

[0098] In this embodiment, based on the steering control unit 20's determination that the steering wheel is in a hands-free state, it also combines the relationship between the steering wheel's requested turning angle and the current turning angle, as well as the condition that the actual return torque value is greater than the return torque threshold number of times within a certain period of time when the lateral control function of the autonomous driving module is activated, to more accurately determine whether the steering wheel is in a hands-free state.

[0099] Figure 4 This is a connection block diagram of a steering wheel hands-off detection device according to another embodiment of the present invention. In one embodiment, as... Figure 3 As shown, after step S400, the following steps are also included:

[0100] Step S500: Issue a hands-off warning when the steering wheel is in a hands-off state;

[0101] Step S600: Stop the hands-off alarm when the steering wheel is in the hands-on state.

[0102] like Figure 4 As shown, the hands-off alarm in step S500 can be emitted through the vehicle's display module 40 in the form of sound, light, text, etc.

[0103] like Figure 2 As shown, the present invention also provides a steering wheel hands-off detection device, including a torque detection unit 10, a steering control unit 20, and an automatic driving control module 30. The torque detection unit 10 is used to detect the actual return torque value of the steering wheel in real time; for example, the torque detection unit 10 can be a torque sensor installed at the steering wheel. The steering control unit 20 is used to learn the system return torque value of the steering wheel after the vehicle's steering system is first powered on, and to generate a hands-off state signal based on the system return torque value and the actual return torque value. The automatic driving control module 30 is used to determine whether the steering wheel is in a hands-off state based on the requested steering angle, the current steering angle, the hands-off state signal, and the actual return torque value.

[0104] The steering wheel hands-off detection device in this embodiment first generates a hands-off status signal based on the system return torque value and the actual return torque value, which is a preliminary detection of whether the steering wheel is off the hands. Based on this hands-off status signal, the requested steering angle, the current steering angle, and the actual return torque value of the steering wheel are combined to jointly determine whether the steering wheel is in a hands-off state, thereby improving the accuracy of determining whether the steering wheel is off the hands and meeting the accuracy requirements of hands-off detection for automatic driving assistance functions.

[0105] In another embodiment, such as Figure 4 As shown, the steering wheel hands-off detection device also includes a display module 40, which is connected to the automatic driving control module 30 and is used to issue a hands-off alarm when it is determined that the steering wheel is in a hands-off state.

[0106] The present invention also provides a vehicle including the steering wheel hands-off detection device of any of the above embodiments.

[0107] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A method for detecting steering wheel release from hands, characterized in that, include: After the vehicle's steering system is powered by electricity, the system learns and obtains the steering wheel's return torque value. Real-time detection of the actual return torque value of the steering wheel; A release status signal is generated based on the system return torque value and the actual return torque value; The system determines whether the steering wheel is in a hands-free state based on the requested steering angle, the current steering angle, the hands-free state signal, and the actual return torque value.

2. The steering wheel hands-off detection method according to claim 1, characterized in that, The steps to learn how to obtain the system's self-centering torque value for the steering wheel include: The first return torque when the steering wheel is turned to the left by a preset angle and the second return torque when the steering wheel is turned to the right by the preset angle are detected; Based on the first positive torque and the second positive torque, the corresponding first learning torque and second learning torque are learned, and the deviation between the first learning torque and the second learning torque is controlled to be less than the deviation threshold. The system return torque value is obtained based on the first learning torque and the second learning torque.

3. The steering wheel hands-off detection method according to claim 2, characterized in that, The steps for deriving the system return torque value based on the first learning torque and the second learning torque include: Calculate the average of the absolute values ​​of the first learning torque and the second learning torque; When the average value is greater than the return torque threshold, the return torque threshold is used as the return torque value of the system. When the mean value is less than or equal to the return torque threshold, the mean value is used as the system return torque value.

4. The steering wheel hands-off detection method according to claim 3, characterized in that, The step of generating a release status signal based on the system return torque value and the actual return torque value includes: The first number of times the absolute difference between the system's return torque value and the actual return torque value is greater than the torque calibration value; When the first number of times reaches a first threshold, a timing is started, and when the timing time reaches a first time threshold, a release signal is generated; The second number of times the absolute value of the difference between the system's return torque value and the actual return torque value is less than or equal to the torque calibration value; When the second number of times reaches the second threshold, a timing is started, and when the timing time reaches the second time threshold, an unreleased signal is generated, wherein the first threshold is greater than the second threshold.

5. The steering wheel hands-off detection method according to claim 4, characterized in that, The steps for determining whether the steering wheel is in a hands-free state based on the requested steering wheel angle, the current steering wheel angle, the hands-free state signal, and the actual return torque value include: The steering wheel is considered to be in a hands-free state when the following conditions are met simultaneously: The requested steering angle of the steering wheel is greater than or equal to the current steering angle of the steering wheel; The release signal was received; Within a third preset time period after the lateral control function of the vehicle's autonomous driving module is activated, the third number of times the actual return torque value is greater than the return torque threshold is less than or equal to the third threshold.

6. The steering wheel hands-off detection method according to claim 5, characterized in that, The step of determining whether the steering wheel is in a hands-free state based on the requested steering wheel angle, the current steering wheel angle, the hands-free state signal, and the actual return torque value further includes: The steering wheel is considered to be in a hands-on state when one of the following conditions is met: The requested steering angle of the steering wheel is less than the current steering angle of the steering wheel; The signal indicating that the item was not released was received; During the third preset time period when the lateral control function of the vehicle's autonomous driving module is activated, the third number of times the actual return torque value is greater than the return torque threshold is greater than the third threshold.

7. The method for detecting steering wheel release from hands according to any one of claims 1-6, characterized in that, After determining whether the steering wheel is in a hands-free state based on the requested steering wheel angle, the current steering wheel angle, the hands-free state signal, and the actual return torque value, the method further includes: A hands-off alarm is triggered when the steering wheel is in a hands-off state. The hands-off alarm will stop when the steering wheel is in the hands-on state.

8. A steering wheel hands-off detection device, characterized in that, include: A torque detection unit is used to detect the actual return torque value of the steering wheel in real time. The steering control unit is used to learn the system return torque value of the steering wheel after the vehicle's steering system is first powered on, and to generate a hands-off state signal based on the system return torque value and the actual return torque value. The automatic driving control module is used to determine whether the steering wheel is in a hands-free state based on the requested steering angle of the steering wheel, the current steering angle of the steering wheel, the hands-free state signal, and the actual return torque value.

9. The steering wheel hands-off detection device according to claim 8, characterized in that, Also includes: The display module, connected to the autonomous driving control module, is used to issue a hands-off alarm when it is determined that the steering wheel is in a hands-off state.

10. A vehicle, characterized in that, Includes the steering wheel hands-off detection device as described in claim 8 or 9.

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