A steering wheel haptic feedback system for vehicle driver assistance

Abstract

This invention provides a steering wheel haptic feedback system for vehicle driver assistance, comprising a vehicle status information acquisition unit, a haptic feedback evaluation index calculation unit, a haptic feedback working mode control unit, and a haptic feedback action execution mechanism unit. The vehicle status information acquisition unit receives vehicle status information collected in real time from sensors; the haptic feedback evaluation index calculation unit calculates vehicle driving state evaluation factors and driver hand state evaluation factors; the haptic feedback working mode control unit selects a suitable haptic feedback working mode from longitudinal action working mode, lateral action working mode, and emergency state working mode based on the vehicle status information; and the haptic feedback action execution mechanism unit executes a specified action according to the selected haptic feedback working mode.

Description

Technical Field

[0001] This invention relates to a steering wheel haptic feedback system for vehicle driver assistance. Background Technology

[0002] With the development of automotive driver assistance technology, cars are becoming increasingly intelligent, leading to a demand for real-time tactile feedback in vehicle driver assistance systems.

[0003] Currently, the steering wheels of cars equipped with driver assistance functions can only recognize and prompt the driver when their hands leave the steering wheel; they cannot provide real-time updates on the vehicle's operating status based on its driving conditions.

[0004] To address the aforementioned issues, this invention proposes a steering wheel haptic feedback system for vehicle driver assistance. Summary of the Invention

[0005] The purpose of this invention is to provide a steering wheel haptic feedback system for vehicle driver assistance, thereby addressing the problems encountered in the background art. To achieve the above objective, this invention provides the following technical solution.

[0006] A steering wheel haptic feedback system for vehicle driver assistance includes: a vehicle status information acquisition unit, a haptic feedback evaluation index calculation unit, a haptic feedback working mode control unit, and a haptic feedback action execution mechanism unit.

[0007] The vehicle status information acquisition unit is used to receive the following information collected in real time from the target vehicle's sensors: front wheel steering angle δ, vehicle speed v, and yaw rate ω. r Side slip angle β, steering wheel angle θ, longitudinal acceleration a x Lateral acceleration a y The target vehicle is a vehicle equipped with driver assistance functions. (The values ​​are: C, ...

[0008] The tactile feedback evaluation index calculation unit is used to calculate the front wheel steering angle δ, vehicle speed v, and yaw rate ω based on the front wheel steering angle δ, vehicle speed v, and yaw rate ω. r The vehicle driving state evaluation factor J1 is calculated based on the sideslip angle β and the center of gravity. The calculation formula for the vehicle driving state evaluation factor J1 is as follows:

[0009]

[0010] Where w1 is the weighted value of the front wheel steering angle δ, w2 is the weighted value of the vehicle speed v, and w3 is the yaw rate ω. rThe weighted value of , w4 is the weighted value of the center of gravity sideslip angle β; f1 is the conversion evaluation factor of the front wheel steering angle δ based on experience, f2 is the conversion evaluation factor of the vehicle speed v based on experience, and f3 is the yaw rate ω based on experience. r The conversion evaluation factor, f4, is the conversion evaluation factor for the centroid sideslip angle β, which is designed based on experience; δ REF The front wheel steering angle reference value calibrated based on the target vehicle model, v REF For the vehicle speed reference value calibrated based on the target vehicle model, ω rREF The yaw rate reference value and β are based on the target vehicle model. REF This is a reference value for the center of gravity sideslip angle calibrated based on the target vehicle model;

[0011] Based on the steering wheel angle θ and the capacitance value C of the steering wheel capacitance sensor, the driver's hand state evaluation factor J2 is calculated. The calculation formula for the driver's hand state evaluation factor J2 is as follows:

[0012]

[0013] Where α1 is the weighted value of the steering wheel angle θ, α2 is the weighted value of the capacitance C of the steering wheel capacitive sensor, and θ max C represents the maximum steering wheel angle of the target vehicle model. REF The value is a reference value for the capacitance of the steering wheel capacitance sensor calibrated based on the target vehicle model, and C≤C. REF ;

[0014] Based on the vehicle driving state evaluation factor J1 and longitudinal acceleration a x Calculate the vehicle longitudinal motion weight factor I x The vehicle longitudinal motion weighting factor I x The calculation formula is as follows:

[0015]

[0016] in, This is the standard threshold value for longitudinal acceleration;

[0017] Based on the vehicle driving state evaluation factor J1 and lateral acceleration a y Calculate the vehicle lateral motion weight factor I y The vehicle lateral motion weighting factor I y The calculation formula is as follows:

[0018]

[0019] in, This is the standard threshold value for lateral acceleration;

[0020] Based on the vehicle driving state evaluation factor J1 and longitudinal acceleration a x Lateral acceleration a y Calculate the vehicle emergency state weighting factor I e The vehicle emergency state weighting factor I e The calculation formula is as follows:

[0021]

[0022] in, This is the standard threshold value for longitudinal acceleration. This is the standard threshold value for lateral acceleration;

[0023] Based on the driver's hand state evaluation factor J2, the driver's hand state H is determined by querying the first mapping relationship rule. The first mapping relationship rule stores the correspondence between the driver's hand state evaluation factor J2 and the driver's hand state H. The driver's hand state H includes a state with hands holding the steering wheel and a state without hands holding the steering wheel. The state with hands holding the steering wheel includes the driver holding the steering wheel with both hands fully and the driver holding the steering wheel with one hand fully. The state without hands holding the steering wheel includes the driver holding the steering wheel with one hand partially and the driver holding the steering wheel without hands.

[0024] The haptic feedback working mode control unit is used to determine the haptic feedback working mode M suitable for the current vehicle working condition by querying the second mapping relationship rule according to the assisted driving action command signal τ. The second mapping relationship rule stores the correspondence between the assisted driving action command signal τ and the haptic feedback working mode M. The haptic feedback working mode M is a longitudinal action working mode, a lateral action working mode, and an emergency state working mode.

[0025] The tactile feedback action execution mechanism unit consists of a servo motor, a transmission mechanism, and a flexible contact area;

[0026] The servo motor includes a longitudinal motion servo motor and a lateral motion servo motor.

[0027] The longitudinal motion working mode refers to the working rules of the longitudinal motion servo motor as follows:

[0028]

[0029] Among them, I x i is the longitudinal motion weighting factor for the vehicle. x This refers to the position loop information of the longitudinal motion servo motor, which is obtained through the longitudinal motion position loop information i. x Perform position control.

[0030] The lateral motion working mode refers to the working rules of the lateral motion servo motor as follows:

[0031]

[0032] Among them, I y i represents the weighting factor for the vehicle's lateral motion. y This refers to the position loop information of the lateral motion servo motor, which is obtained through the lateral motion position loop information i. y Perform position control.

[0033] The emergency working mode refers to the working rules of the longitudinal motion servo motor and the lateral motion servo motor as follows:

[0034]

[0035] Among them, I e i is the vehicle emergency state weighting factor. e For vehicle emergency position loop information, both the longitudinal motion servo motor and the lateral motion servo motor are connected via the vehicle emergency position loop information i. e Perform position control.

[0036] The first mapping relationship rule is:

[0037] Rule (1): When At this time, the driver's hand position H is the state of holding the steering wheel;

[0038] Rule (2): When At this time, the driver's hand position H is a state where the driver is not holding the steering wheel;

[0039] in, These are reference values ​​for driver hand state evaluation factors calibrated based on the target vehicle model.

[0040] The second mapping rule is:

[0041] Rule (1): The assisted driving action command signal τ includes acceleration, deceleration, changing lanes to the left, and changing lanes to the right;

[0042] Rule (2): When the assisted driving action command signal τ is acceleration or deceleration, the haptic feedback working mode M is the longitudinal action working mode;

[0043] Rule (3): When the assisted driving action command signal τ is to change lanes to the left or to the right, the tactile feedback working mode M is the lateral action working mode;

[0044] Rule (4): When At this time, the tactile feedback working mode M is the emergency state working mode;

[0045] Rule (5): The longitudinal motion working mode and the lateral motion working mode are allowed to work simultaneously;

[0046] Rule (6): Rule (4) has a higher priority than Rule (2) and Rule (3);

[0047] in, This is a reference value for the vehicle emergency state weighting factor calibrated based on the target vehicle model.

[0048] The haptic feedback working mode control unit works normally when the driver's hand state J is in the state of holding the steering wheel; the haptic feedback working mode control unit stops working when the driver's hand state H is in the state of not holding the steering wheel, and at the same time the vehicle emits an alarm sound to remind the driver to hold the steering wheel.

[0049] The servo motor and the transmission mechanism are located inside the outer rim of the steering wheel; the flexible contact area is located on the surface of the outer rim of the steering wheel and is parallel to the plane of the outer rim, and the width of the flexible contact area ranges from 0.2D to 0.3D, where D is the diameter of the hand-held portion of the outer rim of the steering wheel; the servo motor drives the flexible contact area to reciprocate through the transmission mechanism, and the reciprocating motion of the flexible contact area provides tactile feedback to the driver; the flexible contact area is made of hydrogenated nitrile rubber.

[0050] The vehicle status information acquisition unit, tactile feedback evaluation index calculation unit, tactile feedback working mode control unit, and tactile feedback action execution mechanism unit are applicable to the vehicle action prompt function of vehicle assisted driving. Attached Figure Description

[0051] Figure 1 This is a flowchart illustrating a steering wheel haptic feedback system for vehicle driver assistance according to the present invention. Detailed Implementation

[0052] To more clearly demonstrate the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] like Figure 1 As shown, this invention provides a steering wheel haptic feedback system for vehicle driver assistance, used to provide real-time feedback to the driver on the operating status of the vehicle's driver assistance system, thereby improving vehicle safety. The invention includes a vehicle status information acquisition unit, a haptic feedback evaluation index calculation unit, a haptic feedback working mode control unit, and a haptic feedback action execution mechanism unit. The method includes the following steps:

[0054] The vehicle status information acquisition unit is used to receive the following information from sensors in real time: front wheel steering angle δ, vehicle speed v, and yaw rate ω. r Side slip angle β, steering wheel angle θ, longitudinal acceleration a x Lateral acceleration a y , Steering wheel capacitance sensor capacitance value C, assisted driving action command signal τ.

[0055] The haptic feedback evaluation index calculation unit is used to calculate the front wheel steering angle δ, vehicle speed v, and yaw rate ω. r The vehicle driving state evaluation factor J1 is calculated based on the centroid sideslip angle β; the driver's hand state evaluation factor J2 is calculated based on the steering wheel angle θ and the steering wheel capacitance sensor value C.

[0056] Vehicle driving status evaluation factor J1 is the vehicle longitudinal motion weight factor I. x Vehicle lateral motion weighting factor I y Vehicle emergency state weighting factor I e The calculation basis; the driver's hand state evaluation factor J2 is the basis for determining the driver's hand state H by querying the first mapping relationship rule.

[0057] The haptic feedback working mode control unit is used to determine the haptic feedback working mode M suitable for the current vehicle working condition by querying the second mapping relationship rule based on the assisted driving action command signal τ, thereby controlling the working state of the haptic feedback action execution mechanism unit.

[0058] The above content describes the main features and basic principles of the present invention. The specific implementation of the present invention is not limited to the above-described methods. Any non-substantial improvements made in accordance with the methodological ideas and technical solutions of the present invention are within the protection scope of the present invention.

Claims

1. A steering wheel haptic feedback system for vehicle assisted driving, characterized in that, Vehicle state information acquisition unit, tactile feedback evaluation index calculation unit, tactile feedback working mode control unit, tactile feedback action execution mechanism unit are consisted of; The vehicle state information acquisition unit is configured to receive the following information collected in real time from a target vehicle sensor: front wheel rotation angle , vehicle speed , yaw rate , center of mass side slip angle , steering wheel rotation angle , longitudinal acceleration , lateral acceleration , steering wheel capacitance sensor capacitance value , auxiliary driving action instruction signal , and the target vehicle is a vehicle with an auxiliary driving function. The tactile feedback evaluation index calculation unit is used to calculate the front wheel angle. Speed yaw rate , centroid side slip angle Calculate the vehicle driving status evaluation factors The vehicle driving status evaluation factor The calculation formula is as follows: ， wherein, is a weighted value of the front wheel steering angle is a weighted value of the vehicle speed is a weighted value of the yaw rate is a weighted value of the center of gravity side slip angle is a weighted value of the front wheel steering angle is a weighted value of the vehicle speed is a weighted value of the yaw rate is a weighted value of the center of gravity side slip angle is a conversion evaluation factor of the front wheel steering angle based on empirical design, is a conversion evaluation factor of the vehicle speed based on empirical design, is a conversion evaluation factor of the yaw rate based on empirical design, is a conversion evaluation factor of the center of gravity side slip angle based on empirical design; is a front wheel steering angle reference value based on target vehicle model calibration, is a vehicle speed reference value based on target vehicle model calibration, is a yaw rate reference value based on target vehicle model calibration, is a center of gravity side slip angle reference value based on target vehicle model calibration. According to the steering wheel angle , steering wheel capacitance sensor capacitance value , the driver hand state evaluation factor , the driver hand state evaluation factor The calculation formula is as follows: ， in, The steering wheel angle weighted value, The capacitance value of the steering wheel capacitive sensor The weighted value, The maximum steering wheel angle for the target vehicle model. The reference value for the steering wheel capacitance sensor is calibrated based on the target vehicle model, and... ; According to the vehicle running state evaluation factor Longitudinal acceleration The vehicle longitudinal action weight factor The vehicle longitudinal action weight factor The calculation formula of the vehicle longitudinal action weight factor is as follows: ， wherein, is a longitudinal acceleration standard threshold value; According to the vehicle running state evaluation factor lateral acceleration , the vehicle lateral action weight factor , the vehicle lateral action weight factor The calculation formula is as follows: ， wherein is a lateral acceleration standard threshold value; According to the vehicle driving state evaluation factor longitudinal acceleration lateral acceleration , a vehicle emergency state weight factor is calculated , the vehicle emergency state weight factor The calculation formula is as follows: ， wherein is a longitudinal acceleration standard threshold value, is a lateral acceleration standard threshold value; According to the driver hand state evaluation factor , the driver hand state is determined by querying a first mapping relationship rule , the first mapping relationship rule stores a corresponding relationship between the driver hand state evaluation factor and the driver hand state ; the driver hand state includes a hand holding steering wheel state and a no hand holding steering wheel state; the hand holding steering wheel state includes a driver both hands completely holding steering wheel state and a driver single hand completely holding steering wheel state; the no hand holding steering wheel state includes a driver single hand incompletely holding steering wheel state and a driver no hand holding steering wheel state; The haptic feedback working mode control unit is configured to determine a haptic feedback working mode suitable for a current vehicle working condition according to the auxiliary driving action instruction signal by querying a second mapping relationship rule , the second mapping relationship rule storing a corresponding relationship between the auxiliary driving action instruction signal and the haptic feedback working mode , the haptic feedback working mode being a longitudinal action working mode, a lateral action working mode, and an emergency state working mode respectively. The tactile feedback action execution mechanism unit includes servo motor, transmission mechanism, flexible contact area group; Wherein, the servo motor includes longitudinal action servo motor and lateral action servo motor.

2. The steering wheel haptic feedback system for vehicle assisted driving of claim 1, wherein, The longitudinal action working mode refers to the working rule of the longitudinal action servo motor is: wherein is a vehicle longitudinal motion weight factor, is a position loop information of a longitudinal motion servo motor, the longitudinal motion servo motor performing position control by means of the position loop information of the longitudinal motion servo motor performs position control.

3. The steering wheel haptic feedback system for vehicle assisted driving of claim 1, wherein, The lateral action working mode refers to the working rule of the lateral action servo motor is: wherein, is a vehicle lateral motion weight factor, is lateral motion servo motor position loop information, the lateral motion servo motor performing position control through the lateral motion servo motor position loop information performs position control.

4. The steering wheel haptic feedback system for assisted driving of a vehicle of claim 1, wherein, The emergency state working mode refers to the working rule of the longitudinal action servo motor and lateral action servo motor is: wherein is a vehicle emergency state weight factor, is a vehicle emergency state position loop information, both the longitudinal action servo motor and the lateral action servo motor being controlled in position by the vehicle emergency state position loop information are controlled in position.

5. The steering wheel haptic feedback system for assisted driving of a vehicle of claim 1, wherein, The first mapping relationship rule is: Rule (1): When the driver's hand state is a hand-holding steering wheel state; Rule (2): When the driver's hand state is a no-hand-holding steering wheel state; wherein, is the driver's hand state evaluation factor reference value based on the target vehicle model calibration.

6. The steering wheel haptic feedback system for assisted driving of a vehicle of claim 1, wherein, The second mapping relationship rule is: Rule (1): the assistant driving action instruction signal including acceleration, deceleration, left lane merging, right lane merging; Rule (2): when the assistant driving action instruction signal is an acceleration or deceleration, the haptic feedback working mode is a longitudinal action working mode; Rule (3): when the assistant driving action instruction signal is a left or right merging signal, the haptic feedback working mode is a lateral action working mode. Rule (4): When the haptic feedback working mode is the emergency state working mode; Rule (5): allow the longitudinal action working mode and the lateral action working mode to work at the same time; Rule (6): the priority of rule (4) is greater than rule (2) and rule (3); wherein, is the vehicle emergency state weight factor reference value based on the target vehicle model calibration.

7. The steering wheel haptic feedback system for assisted driving of a vehicle of claim 1, wherein, The haptic feedback working mode control unit works normally when the driver's hand state is the hand-holding steering wheel state; the haptic feedback working mode control unit stops working when the driver's hand state is the no-hand-holding steering wheel state, and the vehicle issues an alarm sound to prompt the driver to hold the steering wheel.

8. The steering wheel haptic feedback system for assisted driving of a vehicle of claim 1, wherein, The servo motor and the transmission mechanism are located inside the outer ring of the steering wheel; the flexible contact area is located on the surface of the outer ring of the steering wheel and is parallel to the plane where the outer ring of the steering wheel is located, and the width of the flexible contact area is 0.2 to 0.3 , wherein, is the diameter of the handheld part of the outer ring of the steering wheel; the servo motor drives the flexible contact area to reciprocate through the transmission mechanism, and the reciprocating movement of the flexible contact area generates a tactile feedback for the driver.

9. The steering wheel haptic feedback system for assisted driving of a vehicle of claim 1, wherein, The flexible contact area is made of hydrogenated nitrile rubber.

10. The steering wheel haptic feedback system for assisted driving of a vehicle of claim 1, wherein, The vehicle state information acquisition unit, tactile feedback evaluation index calculation unit, tactile feedback working mode control unit, tactile feedback action execution mechanism unit are suitable for vehicle action prompt function of vehicle auxiliary driving.

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