A method for adjusting the angular transmission ratio taking into account the state of takeover by the driver

Abstract

The application discloses a kind of angle transmission ratio adjustment methods considering driver takeover state, the method obtains driver basic attribute data, driving style data, driving ability data, variable angle transmission ratio acceptance data and angle transmission ratio change sensitivity data;The data is limited and normalized, and driver basic attribute factor, driving style extreme degree factor, driving ability factor, driver acceptance factor and driver sensitivity factor are calculated;Then calculate the driver angle transmission ratio offset factor, and combine the angle transmission ratio value before hand off and the angle transmission ratio value of takeover scene target, obtain the individualized offset variable angle transmission ratio under takeover scene;In the preset takeover transition time, real-time angle transmission ratio is generated using a smoothing function and sent to the control unit.The application can take into account the individual differences of driver and the smoothness of takeover process, reduce the abrupt feeling caused by angle transmission ratio change, improve the steering comfort and safety under takeover scene.

Description

Technical Field

[0001] This invention relates to the field of vehicle steer-by-wire systems, and more particularly to a method for adjusting the angular transmission ratio that takes into account the driver's takeover state. Background Technology

[0002] With the development of conditional automated driving and steer-by-wire technologies, the scenarios requiring driver intervention during vehicle transitions between automated driving and manual control are gradually increasing. During automated driving, the driver may be in a hands-free, low-involvement, or distracted state; when the system issues a takeover request, the driver needs to re-engage with vehicle control. At this time, if the angular ratio between the steering wheel angle and the steering wheel angle changes abruptly, it can easily lead to a discrepancy between the driver's expected steering response and the actual vehicle response, resulting in problems such as handling discomfort, overcorrection, or delayed takeover.

[0003] Existing methods for adjusting the gear ratio often design the target gear ratio based on vehicle speed, yaw response, lateral acceleration, or road conditions, but they do not adequately consider the driver's individual takeover state. Different drivers exhibit significant differences in vision, reaction time, driving style, driving control ability, tolerance to gear ratio changes, and sensitivity to gear ratio variations. If the same gear ratio switching strategy is applied to all drivers in takeover scenarios, it may be impossible to simultaneously ensure takeover safety and driver comfort.

[0004] Therefore, it is necessary to propose an angular transmission ratio adjustment method that takes into account the driver takeover state, so that the system can allow the angular transmission ratio to deviate towards the target value of the takeover scenario when the driver has a strong takeover ability, high acceptance and low sensitivity; when the driver is more sensitive to changes in the angular transmission ratio or has insufficient acceptance, the angular transmission ratio deviation should be limited, and the real-time angular transmission ratio should be output in the preset takeover transition time through a smoothing function, thereby improving the smoothness, acceptability and safety of the takeover process. Summary of the Invention

[0005] The purpose of this invention is to provide an angular transmission ratio adjustment method that takes into account the driver's takeover state, in order to solve the problems of existing technologies that do not fully consider the individual state of the driver during autonomous driving takeover, and that changes in angular transmission ratio can easily cause abruptness and discomfort in operation.

[0006] This invention collects driver basic attribute data, driving style data, driving ability data, variable angle transmission ratio acceptance data, and angular transmission ratio change sensitivity data, and obtains the angular transmission ratio value before disengagement and the target angular transmission ratio value in the takeover scenario. The above data is then subjected to amplitude limiting and normalization processing, and driver basic attribute factors, driving style extreme degree factors, driving ability factors, driver acceptance factors, and driver sensitivity factors are calculated respectively. Furthermore, a driver angular transmission ratio offset factor is calculated based on the driving ability factor, driver acceptance factor, and driver sensitivity factor. Combining the angular transmission ratio value before disengagement and the target angular transmission ratio value in the takeover scenario, a personalized offset variable angle transmission ratio is obtained in the takeover scenario. Finally, within a preset takeover transition time, the real-time angular transmission ratio is output through an S-shaped smoothing function, allowing the angular transmission ratio to smoothly transition from the pre-disengagement angular transmission ratio to the personalized offset variable angle transmission ratio.

[0007] This invention is implemented as follows: a method for adjusting the angular transmission ratio considering the driver's take-over state, comprising the following steps:

[0008] S1: Obtain driver's basic attribute data, driving style data, driving ability data, variable angle transmission ratio acceptance data, and angle transmission ratio change sensitivity data, and obtain the angle transmission ratio value before disengagement. and the target angle transmission ratio in the takeover scenario ;

[0009] S2: The driver's basic attribute data, driving style data, driving ability data, variable angle transmission ratio acceptability data, and angle transmission ratio change sensitivity data collected in S1 are subjected to amplitude limiting and normalization processing to calculate the driver's basic attribute factors. Driving style extreme factor Driving ability factor Driver acceptance factor and driver sensitivity factor ;

[0010] S3: Driving ability factor calculated based on S2 Driver acceptance factor and driver sensitivity factor Calculate the driver's angle transmission ratio offset factor The specific calculation formula is as follows:

[0011]

[0012]

[0013] in, as independent variable The limiting function, This is the driver's angle transmission ratio offset factor. For driver sensitivity factors, For driver acceptance factor, For the driver's driving ability factor, The driver sensitivity factor weighting coefficient, The driver acceptance factor weighting coefficient. This refers to the weighting coefficient of the driver's driving ability factor. , ;

[0014] Among them, the driver's basic attribute factors and driving style extreme factor Driver Acceptance Factor Indirectly involved in driver angular transmission ratio offset factor Calculation;

[0015] S4: Based on the driver's angular transmission ratio offset factor Disengagement angle transmission ratio and the target angle transmission ratio in the takeover scenario Calculate the personalized offset variable angle transmission ratio in the takeover scenario. The specific calculation formula is as follows:

[0016]

[0017] in, For personalized offset variable angle transmission ratio, This is the front angle transmission ratio before disengagement. To take over the target angle transmission ratio value in the scene;

[0018] S5: During the preset takeover transition time Internally, the real-time angular transmission ratio is output based on a smoothing function. The specific calculation formula is as follows:

[0019]

[0020]

[0021]

[0022] in, For normalized transition time, It is an S-shaped smoothing function. For real-time angular transmission ratio, For time, The takeover request is triggered at the time of the event. Pre-set takeover transition time;

[0023] S6: The real-time angular transmission ratio The signal is sent to the control unit so that the vehicle operates according to the stated real-time angular transmission ratio during takeover. Adjust the correspondence between the steering wheel angle and the steering wheel angle.

[0024] The limiting and normalization processing includes processing the collected data using a limiting function, a forward normalization function, and a reverse normalization function;

[0025] The limiting function The specific calculation formula is as follows:

[0026]

[0027] in, It is the independent variable of the function;

[0028] The positive normalization function The specific calculation formula is as follows:

[0029]

[0030] in, The lower threshold is... The upper limit threshold, ;

[0031] The reverse normalization function The specific calculation formula is as follows:

[0032]

[0033] The driver's basic attribute factors This is a risk factor; the higher the value, the weaker the driver's basic attributes, and the less favorable their driving skills are for takeover operations. The specific calculation formula is as follows:

[0034]

[0035]

[0036]

[0037]

[0038]

[0039] in, This is a normalized evaluation value for uncorrected visual acuity. This is a normalized evaluation value for driver reaction ability. This is a normalized evaluation value for the number of accidents. This is a normalized evaluation value for spatial cognitive ability scores. For the driver's basic attribute factors, Uncorrected visual acuity, For driver reaction time, For the number of accidents, To score spatial cognitive ability, This is the uncorrected visual acuity weighting coefficient. This is the driver's reaction time weighting coefficient. This is the accident frequency weighting coefficient. This represents the weighting coefficient for spatial cognitive ability scores. , ;

[0040] Uncorrected visual acuity Using the five-point recording rule, the average value of the driver's uncorrected visual acuity in both eyes can be taken; the higher the value, the better the visual foundation.

[0041] The driver's reaction time The time required for the driver to respond effectively to the takeover prompt; a larger value indicates a weaker driver reaction ability, and the unit is seconds.

[0042] The number of accidents The number of traffic accidents the driver has been involved in over the past three years;

[0043] Spatial cognition ability score The range of values ​​is The higher the score, the stronger the driver's spatial cognition ability.

[0044] The driving style extreme factor Characterizing the extreme degree of a driver's driving style, A higher value indicates a more extreme driving style. The smaller the value, the more moderate the driver's driving style. The specific calculation formula is as follows:

[0045]

[0046] in, As a factor of extreme driving style, As an objective data evaluation factor for driver style, This is a correction factor for the subjective driver style questionnaire. Weighting of factors for objective data evaluation of driver style. Adjusting factor weights for the driver style subjective questionnaire. , , The value is selected based on specific needs;

[0047] The objective data evaluation factor of driver style The specific calculation formula is as follows:

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] in, This is the normalized evaluation value of the peak value of the steering wheel angle. This is the normalized evaluation value of the peak value of the steering wheel angular velocity. This is the normalized evaluation value of the peak value of the rate of change of throttle opening. This is a normalized evaluation value for the braking operation frequency. This is the normalized evaluation value of the mean following distance. This is a normalized evaluation value for overtaking frequency. This is the baseline normalized evaluation value for risk preference. Quantify driver style values. As an objective data evaluation factor for driver style, This refers to the peak value of the steering wheel angle. This represents the peak value of the steering wheel angular velocity. This represents the peak value of the rate of change of throttle opening. For braking operation frequency, This is the average following distance. For overtaking frequency, As a baseline for risk appetite, This is the peak weighting coefficient for steering wheel angle. The peak value weighting coefficient for steering wheel angular velocity. The peak weighting coefficient for the rate of change of throttle opening. This is the weighting coefficient for braking operation frequency. The following distance is the average weighting coefficient. This is the overtaking frequency weighting coefficient. The risk preference baseline weighting coefficient, , ;

[0058] Risk preference baseline The range of values ​​is The higher the value, the more aggressive the driver; the lower the value, the more conservative the driver.

[0059] The driver style subjective questionnaire correction factor Driver style subjective questionnaires were used to obtain driver style subjective questionnaire correction factors. The questionnaires included surveys on risk tolerance, steering operation preferences, following distance preferences, and driving speed preferences. The results of the questionnaires were weighted, summed, and linearly mapped to obtain the driver style subjective questionnaire correction factors. The higher the value, the more extreme the driver's driving style.

[0060] The driver's driving ability factor This value is used to characterize the driver's driving control ability in a takeover scenario. A higher value indicates a stronger driving ability, which is more conducive to safety control in a takeover scenario. A lower value indicates a weaker driving ability, which is less conducive to safety control in a takeover scenario. The specific calculation formula is as follows:

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] in, This is a normalized evaluation value for steering wheel angle control capability. This is the normalized evaluation value for path tracking error. This is a normalized evaluation value for the time delay of hazard perception. To provide a normalized evaluation value for the proportion of effective fixation time, This is a normalized evaluation value for the quantified driving time in special scenarios. This is the normalized evaluation value for vehicle speed control stability. For the driver's driving ability factor, To control the deviation rate of steering wheel angle, For path tracking error, Due to the time delay of hazard perception, For the percentage of effective fixation time, Quantification of driving time for specific scenarios To control the fluctuation rate of vehicle speed, This is a weighting coefficient for the steering wheel angle control accuracy. For path tracking error weighting coefficients, This is the weighting coefficient for the time delay in hazard perception. The effective fixation time percentage weighting coefficient, For the quantification of driving time in special scenarios, a weighting coefficient is used. This is the weighting coefficient for vehicle speed control stability. The weighting coefficients are used to couple path tracking error and hazard perception delay. The effective gaze duration and vehicle speed control stability weighting coefficient, , ;

[0069] Steering wheel angle control deviation rate The deviation rate between the driver's steering operation and the target turning angle is presented as a percentage.

[0070] The path tracking error The average deviation between the driving trajectory and the target trajectory, in meters;

[0071] The danger perception time delay The time from the detection of danger to the response is measured in seconds (s).

[0072] The percentage of effective fixation time The percentage of time spent focusing on key areas of the road surface is presented as a percentage.

[0073] The quantification value of driving time in the special scenario The driving time under adverse weather and complex road conditions is quantified in hours (h).

[0074] The vehicle speed control fluctuation rate This is the ratio of the standard deviation of velocity to the mean velocity; the smaller the value, the higher the stability.

[0075] The quantification value of driving time in the special scenario The calculation formula is as follows:

[0076]

[0077] in, For the driver's driving time in adverse weather and complex road conditions, As the minimum duration, This is the maximum duration. The value can be selected according to specific needs.

[0078] The driver acceptance factor Used to characterize the driver's acceptance of variable gear ratios. The range of values ​​is The larger the value, the higher the driver's acceptance of the variable angle transmission ratio. The specific calculation formula is as follows:

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087] in, This is a basic attribute evaluation item for drivers. For driver style evaluation items, This is a normalized evaluation value based on subjective acceptance. The normalized evaluation value is the number of times the steering correction is performed. This is the normalized evaluation value for the steering wheel reverse correction amplitude. To adapt to time-normalized evaluation values, To shift towards a normalized comfort evaluation value, For driver acceptance factor, The driver's subjective acceptance of the variable angle transmission ratio is rated. This refers to the number of steering corrections within a preset time window after takeover. To correct the steering wheel's amplitude in the opposite direction after taking over, This refers to the driver's adaptation time to changes in the variable angle transmission ratio. To shift towards a comfort rating, The weighting coefficients for the driver's basic attributes. For driver style weighting coefficients, This is the subjective acceptance weighting coefficient. The weighting coefficient for the number of reversal corrections. The steering wheel is used to correct the amplitude weighting coefficient in the opposite direction. To accommodate the time weighting coefficient, For steering comfort weighting coefficient, , ;

[0088] The driver's subjective acceptance rating of the variable angle transmission ratio The driver's subjective acceptance of the variable gear ratio was obtained through a questionnaire. The higher the value, the higher the driver's subjective acceptance.

[0089] The number of steering corrections within the preset time window after takeover This refers to the number of times the driver makes steering corrections within a preset time window after the angular transmission ratio changes. The more corrections the driver makes, the less comfortable the driver is with the change and the lower the acceptance level.

[0090] The steering wheel reverse correction amplitude after takeover The magnitude of the driver's steering wheel correction after a change in the gear ratio is expressed as °. The larger the magnitude of the correction, the less the driver is comfortable with the current gear ratio and the lower their acceptance of it.

[0091] The driver's adaptation time to changes in the variable angle transmission ratio The adaptation time is the time required for the driver's operation to return to stability after a change in the angular transmission ratio. The shorter the adaptation time, the higher the acceptance rate; the longer the adaptation time, the lower the acceptance rate. The unit is seconds (s).

[0092] The steering comfort score This is a driver's comfort evaluation of steering feel, steering response, and smoothness of takeover. The higher the value, the more comfortable and acceptable the driver's steering feel is to the changes in the variable angle transmission ratio.

[0093] The driver sensitivity factor This value is used to characterize the driver's sensitivity to changes in the angular gear ratio. The larger the value, the more sensitive the driver is to changes in the angular gear ratio, and the lower the allowable degree of deviation. The specific calculation formula is as follows:

[0094]

[0095]

[0096]

[0097]

[0098] in, This is the normalized evaluation value for the time delay after angular transmission ratio correction. To correct the frequency normalization evaluation value, The normalized evaluation value is the absolute value of the angular velocity difference. For driver sensitivity factors, For angular transmission ratio correction delay, For steering correction frequency, The absolute value of the angular velocity difference. The time delay weighting coefficient is used to correct the angular transmission ratio. To adjust the frequency weighting coefficient for steering, The weighting coefficient is the absolute value of the angular velocity difference. , ;

[0099] The angular transmission ratio correction delay The response time of the driver's first steering correction after a change in the angular gear ratio is measured in seconds. The smaller the delay, the more sensitive the driver is to changes in the angular gear ratio.

[0100] The steering correction frequency This refers to the steering correction frequency within 3 seconds after a change in the angular gear ratio. A higher correction frequency indicates that the driver is more sensitive to changes in the angular gear ratio. The unit is times / second.

[0101] The absolute value of the angular velocity difference It represents the absolute value of the difference in steering wheel angular velocity before and after the change in angular transmission ratio. The larger the difference, the more sensitive the driver is to changes in angular transmission ratio. The unit is ° / s.

[0102] This invention has the following beneficial effects: It incorporates driver's basic attributes, driving style, driving ability, acceptance, and sensitivity into the angular transmission ratio adjustment process, enabling the angular transmission ratio adjustment to reflect the driver's takeover state; and utilizes a driver angular transmission ratio offset factor. The control angle transmission ratio is determined by the pre-disengagement angle transmission ratio value. Target angle transmission ratio in the takeover scenario The degree of offset can balance driver comfort and take-over control requirements; the real-time angular transmission ratio is output through an S-shaped smooth function. It can reduce the steering response shock caused by sudden changes in the angular transmission ratio, improve the smoothness of the takeover process and the human-machine adaptability of the steer-by-wire system. Attached Figure Description

[0103] Figure 1 This is a schematic diagram of the overall process of the present invention;

[0104] Figure 2 This is a schematic diagram of the angular transmission ratio adjustment under the action of the offset factor described in this invention;

[0105] Figure 3 This is a schematic diagram of the real-time angular transmission ratio smooth adjustment process described in this invention. Detailed Implementation

[0106] To make the objectives, technical solutions, and advantages of this invention clearer, the following is combined with... Figures 1 to 3The present invention will be described in more detail below. It is understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention. Where there is no conflict, the embodiments and technical features of the present invention can be combined with each other.

[0107] This invention provides a method for adjusting the angular transmission ratio considering driver takeover states. The method mainly includes steps such as driver state data acquisition, data limiting and normalization processing, multi-factor evaluation of driver takeover states, calculation of the driver angular transmission ratio offset factor, calculation of personalized offset variable angular transmission ratio, and real-time smooth output of the angular transmission ratio. The core of this method is that it does not directly switch the vehicle's angular transmission ratio from the pre-takeover state to the target angular transmission ratio in the takeover scenario. Instead, based on factors such as the driver's basic attributes, driving style, driving ability, acceptance level, and sensitivity, it calculates the acceptable degree of angular transmission ratio offset for the driver, obtains the personalized offset variable angular transmission ratio, and then outputs the real-time angular transmission ratio through a smoothing function, thereby reducing the operational discomfort caused by sudden changes in angular transmission ratio during takeover.

[0108] like Figure 1 As shown in the figure, an embodiment of the present invention provides a method for adjusting the angular transmission ratio considering the driver takeover state. This method collects driver basic attribute data, driving style data, driving ability data, variable angular transmission ratio acceptance data, and angular transmission ratio change sensitivity data, and obtains the angular transmission ratio value before disengagement and the target angular transmission ratio value for the takeover scenario. The above data is then subjected to amplitude limiting and normalization processing, and driver basic attribute factors, driving style extreme degree factors, driving ability factors, driver acceptance factors, and driver sensitivity factors are calculated respectively. Furthermore, a driver angular transmission ratio offset factor is calculated based on the driving ability factor, driver acceptance factor, and driver sensitivity factor. Combining the angular transmission ratio value before disengagement and the target angular transmission ratio value for the takeover scenario, a personalized offset variable angular transmission ratio is obtained under the takeover scenario. Finally, within a preset takeover transition time, the real-time angular transmission ratio is output through an S-shaped smoothing function, allowing the angular transmission ratio to smoothly transition from the pre-disengagement angular transmission ratio to the personalized offset variable angular transmission ratio.

[0109] Specifically, the method includes the following steps:

[0110] S1: Obtain driver's basic attribute data, driving style data, driving ability data, variable angle transmission ratio acceptance data, and angle transmission ratio change sensitivity data, and obtain the angle transmission ratio value before disengagement. and the target angle transmission ratio in the takeover scenario ;

[0111] The release angle transmission ratio The angular transmission ratio used by the vehicle before the driver takes both hands off the steering wheel reflects the steering control relationship that the driver has adapted to before taking over.

[0112] The target angle transmission ratio in the takeover scenario The target angle transmission ratio is determined based on the preset control strategy under the takeover scenario, and is used to characterize the steering response relationship expected to be achieved under the takeover scenario.

[0113] S2: The driver's basic attribute data, driving style data, driving ability data, variable angle transmission ratio acceptability data, and angle transmission ratio change sensitivity data collected in S1 are subjected to amplitude limiting and normalization processing to calculate the driver's basic attribute factors. Driving style extreme factor Driving ability factor Driver acceptance factor and driver sensitivity factor ;

[0114] The limiting and normalization processing includes processing the collected data using a limiting function, a forward normalization function, and a reverse normalization function;

[0115] The limiting function The specific calculation formula is as follows:

[0116]

[0117] in, It is the independent variable of the function;

[0118] The amplitude limiting function can restrict the normalized evaluation quantity to the range of [0,1], thus avoiding the excessive impact of outlier data on subsequent calculations.

[0119] The positive normalization function The specific calculation formula is as follows:

[0120]

[0121] in, The lower threshold is... The upper limit threshold, ;

[0122] The reverse normalization function The specific calculation formula is as follows:

[0123]

[0124] Forward normalization functions are suitable for evaluation indicators where larger values ​​are more advantageous, while backward normalization functions are suitable for evaluation indicators where smaller values ​​are more advantageous.

[0125] The driver's basic attribute factors This is a risk factor; a higher value indicates weaker basic driver attributes and a less favorable driving foundation for takeover operations. Specifically, the normalized evaluation value of each basic attribute is calculated according to the following formula:

[0126]

[0127]

[0128]

[0129]

[0130] in, This is a normalized evaluation value for uncorrected visual acuity. This is a normalized evaluation value for driver reaction ability. This is a normalized evaluation value for the number of accidents. This is a normalized evaluation value for spatial cognitive ability scores. Uncorrected visual acuity, For driver reaction time, For the number of accidents, Scoring based on spatial cognitive ability;

[0131] The driver's basic attribute factors The calculation formula is as follows:

[0132]

[0133] in, For the driver's basic attribute factors, This is the uncorrected visual acuity weighting coefficient. This is the driver's reaction time weighting coefficient. This is the accident frequency weighting coefficient. This represents the weighting coefficient for spatial cognitive ability scores. , ;

[0134] Uncorrected visual acuity Using the five-point recording rule, the average value of the driver's uncorrected visual acuity in both eyes can be taken; the higher the value, the better the visual foundation.

[0135] The driver's reaction time The time required for the driver to respond effectively to the takeover prompt; a larger value indicates a weaker driver reaction ability, and the unit is seconds.

[0136] The number of accidents The number of traffic accidents the driver has been involved in over the past three years;

[0137] Spatial cognition ability score The range of values ​​is The higher the score, the stronger the driver's spatial cognition ability.

[0138] The driving style extreme factor Characterizing the extreme degree of a driver's driving style, A higher value indicates a more extreme driving style. The smaller the value, the more moderate the driver's driving style. The specific calculation formula is as follows:

[0139]

[0140] in, As a factor of extreme driving style, As an objective data evaluation factor for driver style, This is a correction factor for the subjective driver style questionnaire. Weighting of factors for objective data evaluation of driver style. Adjusting factor weights for the driver style subjective questionnaire. , , The value is selected based on specific needs;

[0141] The objective data evaluation factor of driver style It is calculated using peak steering wheel angle, peak steering wheel angular velocity, peak throttle opening change rate, braking frequency, average following distance, overtaking frequency, and risk preference baseline. Specifically:

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148]

[0149] in, This is the normalized evaluation value of the peak value of the steering wheel angle. This is the normalized evaluation value of the peak value of the steering wheel angular velocity. This is the normalized evaluation value of the peak value of the rate of change of throttle opening. This is a normalized evaluation value for the braking operation frequency. This is the normalized evaluation value of the mean following distance. This is a normalized evaluation value for overtaking frequency. This is the baseline normalized evaluation value for risk preference. This refers to the peak value of the steering wheel angle. This represents the peak value of the steering wheel angular velocity. This represents the peak value of the rate of change of throttle opening. For braking operation frequency, This is the average following distance. For overtaking frequency, This serves as a baseline for risk appetite;

[0150] Further calculation of driver style quantification value :

[0151]

[0152] in, Quantify driver style values. This is the peak weighting coefficient for steering wheel angle. The peak value weighting coefficient for steering wheel angular velocity. The peak weighting coefficient for the rate of change of throttle opening. This is the weighting coefficient for braking operation frequency. The following distance is the average weighting coefficient. This is the overtaking frequency weighting coefficient. The risk preference baseline weighting coefficient, , ;

[0153] The objective data evaluation factor of driver style The calculation formula is as follows:

[0154]

[0155] in, As an objective data evaluation factor for driver style;

[0156] This formula is used to characterize the degree to which driving style deviates from the moderate state: when When the value approaches 0.5, the driving style becomes more moderate. Smaller; when When approaching 0 or 1, the driving style tends to be either extremely conservative or extremely aggressive, respectively. Larger;

[0157] Risk preference baseline The range of values ​​is The higher the value, the more aggressive the driver; the lower the value, the more conservative the driver.

[0158] The driver style subjective questionnaire correction factor Driver style subjective questionnaires were used to obtain driver style subjective questionnaire correction factors. The questionnaires included surveys on risk tolerance, steering operation preferences, following distance preferences, and driving speed preferences. The results of the questionnaires were weighted, summed, and linearly mapped to obtain the driver style subjective questionnaire correction factors. The higher the value, the more extreme the driver's driving style.

[0159] The driver's driving ability factor This value characterizes a driver's driving control ability under takeover scenarios. A higher value indicates stronger driving ability, which is more conducive to safety control under takeover scenarios; a lower value indicates weaker driving ability, which is less conducive to safety control under takeover scenarios. The specific calculation formula is as follows:

[0160]

[0161]

[0162]

[0163]

[0164]

[0165]

[0166] in, This is a normalized evaluation value for steering wheel angle control capability. This is the normalized evaluation value for path tracking error. This is a normalized evaluation value for the time delay of hazard perception. To provide a normalized evaluation value for the proportion of effective fixation time, This is a normalized evaluation value for the quantified driving time in special scenarios. This is the normalized evaluation value for vehicle speed control stability. To control the deviation rate of steering wheel angle, For path tracking error, Due to the time delay of hazard perception, For the percentage of effective fixation time, Quantification of driving time for specific scenarios To control the fluctuation rate of vehicle speed;

[0167] The driver's driving ability factor The calculation formula is as follows:

[0168]

[0169] in, For the driver's driving ability factor, This is a weighting coefficient for the steering wheel angle control accuracy. For path tracking error weighting coefficients, This is the weighting coefficient for the time delay in hazard perception. The effective fixation time percentage weighting coefficient, For the quantification of driving time in special scenarios, a weighting coefficient is used. This is the weighting coefficient for vehicle speed control stability. The weighting coefficients are used to couple path tracking error and hazard perception delay. The effective gaze duration and vehicle speed control stability weighting coefficient, , ;

[0170] Steering wheel angle control deviation rate The deviation rate between the driver's steering operation and the target turning angle is presented as a percentage.

[0171] The path tracking error The average deviation between the driving trajectory and the target trajectory, in meters;

[0172] The danger perception time delay The time from the detection of danger to the response is measured in seconds (s).

[0173] The percentage of effective fixation time The percentage of time spent focusing on key areas of the road surface is presented as a percentage.

[0174] The quantification value of driving time in the special scenario The driving time under adverse weather and complex road conditions is quantified in hours (h).

[0175] The vehicle speed control fluctuation rate This is the ratio of the standard deviation of velocity to the mean velocity; the smaller the value, the higher the stability.

[0176] The quantification value of driving time in the special scenario The calculation formula is as follows:

[0177]

[0178] in, For the driver's driving time in adverse weather and complex road conditions, As the minimum duration, This is the maximum duration. The value can be selected according to specific needs.

[0179] The driver acceptance factor Used to characterize the driver's acceptance of variable gear ratios. The range of values ​​is The larger the value, the higher the driver's acceptance of the variable angle transmission ratio. The specific calculation formula is as follows:

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187] in, This is a basic attribute evaluation item for drivers. For driver style evaluation items, This is a normalized evaluation value based on subjective acceptance. The normalized evaluation value is the number of times the steering correction is performed. This is the normalized evaluation value for the steering wheel reverse correction amplitude. To adapt to time-normalized evaluation values, To shift towards a normalized comfort evaluation value, The driver's subjective acceptance of the variable angle transmission ratio is rated. This refers to the number of steering corrections within a preset time window after takeover. To correct the steering wheel's amplitude in the opposite direction after taking over, This refers to the driver's adaptation time to changes in the variable angle transmission ratio. Rating for steering comfort;

[0188] The driver acceptance factor The calculation formula is as follows:

[0189]

[0190] in, For driver acceptance factor, The weighting coefficients for the driver's basic attributes. For driver style weighting coefficients, This is the subjective acceptance weighting coefficient. The weighting coefficient for the number of reversal corrections. The steering wheel is used to correct the amplitude weighting coefficient in the opposite direction. To accommodate the time weighting coefficient, For steering comfort weighting coefficient, , ;

[0191] The driver's subjective acceptance rating of the variable angle transmission ratio The driver's subjective acceptance of the variable gear ratio was obtained through a questionnaire. The higher the value, the higher the driver's subjective acceptance.

[0192] The number of steering corrections within the preset time window after takeover This refers to the number of times the driver makes steering corrections within a preset time window after the angular transmission ratio changes. The more corrections the driver makes, the less comfortable the driver is with the change and the lower the acceptance level.

[0193] The steering wheel reverse correction amplitude after takeover The magnitude of the driver's steering wheel correction after a change in the gear ratio is expressed as °. The larger the magnitude of the correction, the less the driver is comfortable with the current gear ratio and the lower their acceptance of it.

[0194] The driver's adaptation time to changes in the variable angle transmission ratio The adaptation time is the time required for the driver's operation to return to stability after a change in the angular transmission ratio. The shorter the adaptation time, the higher the acceptance rate; the longer the adaptation time, the lower the acceptance rate. The unit is seconds (s).

[0195] The steering comfort score This is a driver's comfort evaluation of steering feel, steering response, and smoothness of takeover. The higher the value, the more comfortable and acceptable the driver's steering feel is to the changes in the variable angle transmission ratio.

[0196] The driver sensitivity factor This value is used to characterize the driver's sensitivity to changes in the angular gear ratio. The larger the value, the more sensitive the driver is to changes in the angular gear ratio, and the lower the allowable degree of deviation. The specific calculation formula is as follows:

[0197]

[0198]

[0199]

[0200] in, This is the normalized evaluation value for the time delay after angular transmission ratio correction. To correct the frequency normalization evaluation value, The normalized evaluation value is the absolute value of the angular velocity difference. For angular transmission ratio correction delay, For steering correction frequency, The absolute value of the angular velocity difference;

[0201] The driver sensitivity factor The calculation formula is as follows:

[0202]

[0203] in, For driver sensitivity factors, The time delay weighting coefficient is used to correct the angular transmission ratio. To adjust the frequency weighting coefficient for steering, The weighting coefficient is the absolute value of the angular velocity difference. , ;

[0204] The angular transmission ratio correction delay The response time of the driver's first steering correction after a change in the angular gear ratio is measured in seconds. The smaller the delay, the more sensitive the driver is to changes in the angular gear ratio.

[0205] The steering correction frequency This refers to the steering correction frequency within 3 seconds after a change in the angular gear ratio. A higher correction frequency indicates that the driver is more sensitive to changes in the angular gear ratio. The unit is times / second.

[0206] The absolute value of the angular velocity difference It represents the absolute value of the difference in steering wheel angular velocity before and after the change in angular transmission ratio. The larger the difference, the more sensitive the driver is to changes in angular transmission ratio. The unit is ° / s.

[0207] S3: Driving ability factor calculated based on S2 Driver acceptance factor and driver sensitivity factor Calculate the driver's angle transmission ratio offset factor The specific calculation formula is as follows:

[0208]

[0209] in, This is the driver's angle transmission ratio offset factor. For driver sensitivity factors, For driver acceptance factor, For the driver's driving ability factor, The driver sensitivity factor weighting coefficient, The driver acceptance factor weighting coefficient. This refers to the weighting coefficient of the driver's driving ability factor. , ;

[0210] Among them, the driver's basic attribute factors and driving style extreme factor Driver Acceptance Factor Indirectly involved in driver angular transmission ratio offset factor Calculation;

[0211] Due to driver sensitivity factor A larger value indicates that the driver is more sensitive to changes in the angular transmission ratio. Therefore, when calculating the driver's angular transmission ratio offset factor, the value is... As a sensitivity correction term, the lower the driver's sensitivity, the more suitable the angular transmission ratio is to shift towards the target angular transmission ratio in the takeover scenario. Driver basic attribute factor. and driving style extreme factor Driver Acceptance Factor It indirectly participates in the calculation of the driver's angular transmission ratio offset factor, thereby subjecting drivers with weak basic attributes or extreme driving styles to corresponding constraints in the acceptance evaluation.

[0212] S4: Based on the driver's angular transmission ratio offset factor Disengagement angle transmission ratio and the target angle transmission ratio in the takeover scenario Calculate the personalized offset variable angle transmission ratio in the takeover scenario. The specific calculation formula is as follows:

[0213]

[0214] in, For personalized offset variable angle transmission ratio, This is the front angle transmission ratio before disengagement. To take over the target angle transmission ratio value in the scene;

[0215] From this formula, we can see that when hour, This indicates that the system maintains the pre-disengagement gear ratio; when hour, This indicates that the system fully adopts the target angle transmission ratio of the takeover scenario; when hour, lie in and This allows for personalized adjustments to determine the degree of deviation based on the driver's takeover status.

[0216] like Figure 2 As shown, offset factor The value of determines the personalized offset variable angle transmission ratio. Before disengagement, the transmission ratio is... Transmission ratio of target angle in the takeover scenario The position between. When When smaller, Closer This helps maintain the continuity of operation before and after the driver takes over; when When it is large, Closer This facilitates the transition of the vehicle's steering response to the target state in the driver takeover scenario. Therefore, embodiments of the present invention can continuously adjust the angular transmission ratio offset according to the driver's takeover state, rather than using abrupt switching.

[0217] S5: During the preset takeover transition time Internally, the real-time angular transmission ratio is output based on a smoothing function. The specific calculation formula is as follows:

[0218]

[0219]

[0220]

[0221] in, For normalized transition time, It is an S-shaped smoothing function. For real-time angular transmission ratio, For time, The takeover request is triggered at the time of the event. Pre-set takeover transition time;

[0222] like Figure 3 As shown, in hour, , Real-time angular transmission ratio Maintain the front gear ratio for disengagement. ;exist hour, Smoothly increase from 0 to 1. The real-time angular transmission ratio increases from 0 to 1 according to the S-shaped curve. Depend on Smooth transition to ;exist hour, , Real-time angular transmission ratio Maintain the personalized offset variable angle transmission ratio This S-shaped smoothing function allows for a smaller rate of change in the angular transmission ratio during the initial and final stages of the transition, reducing steering shock caused by sudden changes and improving handling smoothness during driver takeover.

[0223] Furthermore, in S4 Substituting into the real-time angular transmission ratio calculation formula in S5, we can obtain:

[0224]

[0225] This formula shows that the final release degree of the real-time angular transmission ratio is simultaneously affected by the driver's angular transmission ratio offset factor. and time smoothing function The combined effect of. Among them, Characterizes the degree of angular gear ratio deviation permissible under driver conditions. This characterizes the degree of time release within the preset takeover transition period. Therefore, this invention can both control the angular transmission ratio offset target according to individual driver differences and smoothly release angular transmission ratio changes over time.

[0226] S6: The real-time angular transmission ratio The signal is sent to the control unit so that the vehicle operates according to the stated real-time angular transmission ratio during takeover. Adjust the correspondence between the steering wheel angle and the steering wheel angle.

[0227] Specifically, the control unit receives the real-time angular transmission ratio. Then, based on the steering wheel angle input and the real-time angular transmission ratio, the target steering wheel angle is calculated, and the steer-by-wire actuator is controlled to complete the corresponding steering action. Because... During the takeover process, the steering wheel angle and the steering wheel angle are continuously changed, and the mapping relationship is also smoothly adjusted accordingly, thereby avoiding discomfort or misoperation of the driver due to sudden changes in steering response at the beginning of the takeover.

[0228] This invention provides a method for adjusting the angular transmission ratio that takes into account the driver's takeover state through the above steps. This method comprehensively considers the driver's basic attributes, driving style, driving ability, tolerance to variable angular transmission ratio, and sensitivity to angular transmission ratio changes. It can determine the degree of angular transmission ratio offset based on the driver's current takeover state. Simultaneously, it utilizes an S-shaped smoothing function to output the real-time angular transmission ratio within a preset takeover transition time, allowing the angular transmission ratio to smoothly transition from the pre-takeover state to the personalized offset state. Compared to methods that directly switch the angular transmission ratio, this invention reduces the abruptness and discomfort caused by angular transmission ratio changes, improving steering adaptability, handling comfort, and safety in autonomous driving takeover scenarios.

Claims

1. A method for adjusting the angular transmission ratio considering the driver's take-over state, characterized in that, Includes the following steps: S1: Obtain driver's basic attribute data, driving style data, driving ability data, variable angle transmission ratio acceptance data, and angle transmission ratio change sensitivity data, and obtain the angle transmission ratio value before disengagement. and the target angle transmission ratio in the takeover scenario ; S2: The data collected in S1 is subjected to amplitude limiting and normalization processing to calculate the driver's basic attribute factors. Driving style extreme factor Driving ability factor Driver acceptance factor and driver sensitivity factor ; S3: Calculated based on S2 , and Calculate the driver's angle transmission ratio offset factor The specific calculation formula is as follows: in, as independent variable The limiting function, This is the driver's angle transmission ratio offset factor. For driver sensitivity factors, For driver acceptance factor, For the driver's driving ability factor, The driver sensitivity factor weighting coefficient, The driver acceptance factor weighting coefficient. This refers to the weighting coefficient of the driver's driving ability factor. , ; S4: According to , and Calculate the personalized offset variable angle transmission ratio in the takeover scenario. The specific calculation formula is as follows: in, For personalized offset variable angle transmission ratio, This is the front angle transmission ratio before disengagement. To take over the target angle transmission ratio value in the scene; S5: During the preset takeover transition time Internally, the real-time angular transmission ratio is output based on a smoothing function. The specific calculation formula is as follows: in, For normalized transition time, It is an S-shaped smoothing function. For real-time angular transmission ratio, For time, The takeover request is triggered at the time of the event. Pre-set takeover transition time; S6: The real-time angular transmission ratio The signal is sent to the control unit so that the vehicle operates according to the stated real-time angular transmission ratio during takeover. Adjust the correspondence between the steering wheel angle and the steering wheel angle.

2. The angular transmission ratio adjustment method considering driver take-off state according to claim 1, characterized in that, The limiting and normalization processing includes processing the collected data using a limiting function, a forward normalization function, and a reverse normalization function; The limiting function The specific calculation formula is as follows: in, It is the independent variable of the function; The positive normalization function The specific calculation formula is as follows: in, The lower threshold is... The upper limit threshold, ; The reverse normalization function The specific calculation formula is as follows: The driver's basic attribute factors This is a risk factor; the higher the value, the weaker the driver's basic attributes, and the less favorable their driving skills are for takeover operations. The specific calculation formula is as follows: in, This is a normalized evaluation value for uncorrected visual acuity. This is a normalized evaluation value for driver reaction ability. This is a normalized evaluation value for the number of accidents. This is a normalized evaluation value for spatial cognitive ability scores. For the driver's basic attribute factors, Uncorrected visual acuity, For driver reaction time, For the number of accidents, To score spatial cognitive ability, This is the uncorrected visual acuity weighting coefficient. This is the driver's reaction time weighting coefficient. This is the accident frequency weighting coefficient. This represents the weighting coefficient for spatial cognitive ability scores. , ; Uncorrected visual acuity Using the five-point recording rule, the average value of the driver's uncorrected visual acuity in both eyes can be taken; the higher the value, the better the visual foundation. The driver's reaction time The time required for the driver to respond effectively to the takeover prompt; a larger value indicates a weaker driver reaction ability, and the unit is seconds. The number of accidents The number of traffic accidents the driver has been involved in over the past three years; Spatial cognition ability score The range of values ​​is The higher the score, the stronger the driver's spatial cognition ability.

3. The angular transmission ratio adjustment method considering driver take-off state according to claim 1, characterized in that, The driving style extreme factor Characterizing the extreme degree of a driver's driving style, A higher value indicates a more extreme driving style. The smaller the value, the more moderate the driver's driving style. The specific calculation formula is as follows: in, As a factor of extreme driving style, As an objective data evaluation factor for driver style, This is a correction factor for the subjective driver style questionnaire. Weighting of factors for objective data evaluation of driver style. Adjusting factor weights for the driver style subjective questionnaire. , , The value is selected based on specific needs; The objective data evaluation factor of driver style The specific calculation formula is as follows: in, This is the normalized evaluation value of the peak value of the steering wheel angle. This is the normalized evaluation value of the peak value of the steering wheel angular velocity. This is the normalized evaluation value of the peak value of the rate of change of throttle opening. This is a normalized evaluation value for the braking operation frequency. This is the normalized evaluation value of the mean following distance. This is a normalized evaluation value for overtaking frequency. This is the baseline normalized evaluation value for risk preference. Quantify driver style values. As an objective data evaluation factor for driver style, This refers to the peak value of the steering wheel angle. This represents the peak value of the steering wheel angular velocity. This represents the peak value of the rate of change of throttle opening. For braking operation frequency, This is the average following distance. For overtaking frequency, As a baseline for risk appetite, This is the peak weighting coefficient for steering wheel angle. The peak value weighting coefficient for steering wheel angular velocity. The peak weighting coefficient for the rate of change of throttle opening. This is the weighting coefficient for braking operation frequency. The following distance is the average weighting coefficient. This is the overtaking frequency weighting coefficient. The risk preference baseline weighting coefficient, , ; Risk preference baseline The range of values ​​is The higher the value, the more aggressive the driver; the lower the value, the more conservative the driver. The driver style subjective questionnaire correction factor Driver style subjective questionnaires were used to obtain driver style subjective questionnaire correction factors. The questionnaires included surveys on risk tolerance, steering operation preferences, following distance preferences, and driving speed preferences. The results of the questionnaires were weighted, summed, and linearly mapped to obtain the driver style subjective questionnaire correction factors. The higher the value, the more extreme the driver's driving style.

4. The angular transmission ratio adjustment method considering driver take-off state according to claim 1, characterized in that, The driver's driving ability factor This value is used to characterize the driver's driving control ability in a takeover scenario. A higher value indicates a stronger driving ability, which is more conducive to safety control in a takeover scenario. A lower value indicates a weaker driving ability, which is less conducive to safety control in a takeover scenario. The specific calculation formula is as follows: in, This is a normalized evaluation value for steering wheel angle control capability. This is the normalized evaluation value for path tracking error. This is a normalized evaluation value for the time delay of hazard perception. To provide a normalized evaluation value for the proportion of effective fixation time, This is a normalized evaluation value for the quantified driving time in special scenarios. This is the normalized evaluation value for vehicle speed control stability. For the driver's driving ability factor, To control the deviation rate of steering wheel angle, For path tracking error, Due to the time delay of hazard perception, For the percentage of effective fixation time, Quantification of driving time for specific scenarios To control the fluctuation rate of vehicle speed, This is a weighting coefficient for the steering wheel angle control accuracy. For path tracking error weighting coefficients, This is the weighting coefficient for the time delay in hazard perception. The effective fixation time percentage weighting coefficient, For the quantification of driving time in special scenarios, a weighting coefficient is used. This is the weighting coefficient for vehicle speed control stability. The weighting coefficients are used to couple path tracking error and hazard perception delay. The effective gaze duration and vehicle speed control stability weighting coefficient, , ; Steering wheel angle control deviation rate The deviation rate between the driver's steering operation and the target turning angle is presented as a percentage. The path tracking error The average deviation between the driving trajectory and the target trajectory, in meters; The danger perception time delay The time from the detection of danger to the response is measured in seconds (s). The percentage of effective fixation time The percentage of time spent focusing on key areas of the road surface is presented as a percentage. The quantification value of driving time in the special scenario The driving time under adverse weather and complex road conditions is quantified in hours (h). The vehicle speed control fluctuation rate This is the ratio of the standard deviation of velocity to the mean velocity; the smaller the value, the higher the stability. The quantification value of driving time in the special scenario The calculation formula is as follows: in, For the driver's driving time in adverse weather and complex road conditions, As the minimum duration, This is the maximum duration. The value can be selected according to specific needs.

5. The angular transmission ratio adjustment method considering driver take-off state according to claim 1, characterized in that, The driver acceptance factor Used to characterize the driver's acceptance of variable gear ratios. The range of values ​​is The larger the value, the higher the driver's acceptance of the variable angle transmission ratio. The specific calculation formula is as follows: in, This is a basic attribute evaluation item for drivers. For driver style evaluation items, This is a normalized evaluation value based on subjective acceptance. The normalized evaluation value is the number of times the steering correction is performed. This is the normalized evaluation value for the steering wheel reverse correction amplitude. To adapt to time-normalized evaluation values, To shift towards a normalized comfort evaluation value, For driver acceptance factor, The driver's subjective acceptance of the variable angle transmission ratio is rated. This refers to the number of steering corrections within a preset time window after takeover. To correct the steering wheel's amplitude in the opposite direction after taking over, This refers to the driver's adaptation time to changes in the variable angle transmission ratio. To shift towards a comfort rating, The weighting coefficients for the driver's basic attributes. For driver style weighting coefficients, This is the subjective acceptance weighting coefficient. The weighting coefficient for the number of reversal corrections. The steering wheel is used to correct the amplitude weighting coefficient in the opposite direction. To accommodate the time weighting coefficient, For steering comfort weighting coefficient, , ; The driver's subjective acceptance rating of the variable angle transmission ratio The driver's subjective acceptance of the variable gear ratio was obtained through a questionnaire. The higher the value, the higher the driver's subjective acceptance. The number of steering corrections within the preset time window after takeover This refers to the number of times the driver makes steering corrections within a preset time window after the angular transmission ratio changes. The more corrections the driver makes, the less comfortable the driver is with the change and the lower the acceptance level. The steering wheel reverse correction amplitude after takeover The magnitude of the driver's steering wheel correction after a change in the gear ratio is expressed as °. The larger the magnitude of the correction, the less the driver is comfortable with the current gear ratio and the lower their acceptance of it. The driver's adaptation time to changes in the variable angle transmission ratio The adaptation time is the time required for the driver's operation to return to stability after a change in the angular transmission ratio. The shorter the adaptation time, the higher the acceptance rate; the longer the adaptation time, the lower the acceptance rate. The unit is seconds (s). The steering comfort score This is a driver's comfort evaluation of steering feel, steering response, and smoothness of takeover. The higher the value, the more comfortable and acceptable the driver's steering feel is to the changes in the variable angle transmission ratio.

6. The angular transmission ratio adjustment method considering driver take-off state according to claim 1, characterized in that, The driver sensitivity factor This value is used to characterize the driver's sensitivity to changes in the angular gear ratio. The larger the value, the more sensitive the driver is to changes in the angular gear ratio, and the lower the allowable degree of deviation. The specific calculation formula is as follows: in, This is the normalized evaluation value for the time delay after angular transmission ratio correction. To correct the frequency normalization evaluation value, The normalized evaluation value is the absolute value of the angular velocity difference. For driver sensitivity factors, For angular transmission ratio correction delay, For steering correction frequency, The absolute value of the angular velocity difference. The time delay weighting coefficient is used to correct the angular transmission ratio. To adjust the frequency weighting coefficient for steering, The weighting coefficient is the absolute value of the angular velocity difference. , ; The angular transmission ratio correction delay The response time of the driver's first steering correction after a change in the angular gear ratio is measured in seconds. The smaller the delay, the more sensitive the driver is to changes in the angular gear ratio. The steering correction frequency This refers to the steering correction frequency within 3 seconds after a change in the angular gear ratio. A higher correction frequency indicates that the driver is more sensitive to changes in the angular gear ratio. The unit is times / second. The absolute value of the angular velocity difference It represents the absolute value of the difference in steering wheel angular velocity before and after the change in angular transmission ratio. The larger the difference, the more sensitive the driver is to changes in angular transmission ratio. The unit is ° / s.

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