Driving control device, vehicle, driving control method and program

Abstract

To provide a travel control device which can reduce vehicle rollover risk.SOLUTION: A travel control device acquires a velocity in a direction of travel, a velocity in a horizontal direction, and an azimuth angular velocity of a vehicle and calculates a rollover risk degree based on LTR (Lateral Load Transfer Ratio), calculates a deceleration which indicates a degree of decreasing the velocity in the direction of travel when the rollover risk degree exceeds a threshold, and controls travel of the vehicle with a value that a target velocity is decelerated on the basis of the deceleration as a new target velocity.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cruise control device, a vehicle, a cruise control method, and a program. [Background technology]

[0002] There has been provided a cruise control method for moving a vehicle along a target route while taking into account the effects of disturbances. For example, in the cruise control disclosed in Patent Document 1, a sensor for detecting wind direction and wind speed is attached to the vehicle, and the wind direction and wind speed at a point where the vehicle is traveling are calculated. Then, a basic steering angle, which is the steering angle amount required to travel the vehicle along the target route, is calculated, and a correction steering angle for canceling out disturbances applied to the vehicle due to the effects of wind is calculated. Furthermore, a target steering angle that takes into account the effects of wind is calculated by adding the basic steering angle and the correction steering angle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6784633 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if the amount of steering angle correction in response to disturbance is taken into consideration, if the amount of disturbance is excessive, the steering angle may be operated too abruptly relative to the vehicle speed, which may result in the risk of the vehicle rolling over.

[0005] The present disclosure provides a cruise control device, a vehicle, a cruise control method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] The cruise control device of the present disclosure includes a risk calculation unit that acquires the speed of the vehicle in the traveling direction, the speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and the azimuth angular velocity of the vehicle to calculate a rollover risk based on an LTR (Lateral Load Transfer Ratio) of the vehicle; a deceleration calculation unit that calculates a deceleration indicating a degree to which the speed in the traveling direction is to be decelerated when the absolute value of the rollover risk exceeds a threshold; and a control unit that controls a drive system of the vehicle by setting a value obtained by reducing a target speed of the vehicle based on the deceleration as the new target speed. The deceleration calculation unit calculates the deceleration by multiplying the difference between the absolute value of the rollover risk and a threshold value by a predetermined coefficient.

[0007] A vehicle according to the present disclosure includes the above-described driving control device.

[0008] The driving control method of the present disclosure includes: The driving control device a step of acquiring a speed of the vehicle in a traveling direction, a speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and an azimuth angular velocity of the vehicle, and calculating a rollover risk based on the LTR of the vehicle; The driving control device When the absolute value of the rollover risk exceeds a threshold, calculating a deceleration indicating a degree of deceleration of the speed in the traveling direction; The driving control device a step of controlling a drive system of the vehicle by setting a value obtained by reducing the target speed of the vehicle based on the deceleration as a new target speed. In the step of calculating the deceleration, the driving control device calculates the deceleration by multiplying the difference between the absolute value of the rollover risk and a threshold value by a predetermined coefficient.

[0009] The program of the present disclosure includes the steps of causing a computer to perform the following operations: acquiring a speed of the vehicle in a traveling direction, a speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and an azimuth angular velocity of the vehicle, and calculating a rollover risk level based on the LTR of the vehicle; if the absolute value of the rollover risk level exceeds a threshold, calculating a deceleration indicating a degree to which the speed in the traveling direction is to be decelerated; and calculating a value obtained by decelerating a target speed of the vehicle based on the deceleration as a new target speed. and in the step of calculating the deceleration, a process of calculating the deceleration by multiplying a difference between the absolute value of the rollover risk and a threshold value by a predetermined coefficient. Execute the following. [Effects of the Invention]

[0010] According to the above-described driving control device, vehicle, driving control method, and program, the risk of the vehicle rolling over can be reduced. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of a driving control device according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating the azimuthal velocity of a vehicle. [Figure 3] FIG. 1 is a diagram for explaining an LTR calculation method according to an embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a calculation process of a vehicle speed according to the embodiment. [Figure 5] FIG. 10 is a diagram illustrating an example of the effect of deceleration control according to the embodiment. [Figure 6] FIG. 5 is a diagram illustrating an example of a calculation process of a steering angle according to the embodiment. [Figure 7] FIG. 10 is a diagram illustrating an example of the effect of disturbance suppression control according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The driving control device of the present disclosure will be described below with reference to Figures 1 to 7. In the following description, components having the same or similar functions will be assigned the same reference numerals, and redundant descriptions of those components may be omitted.

[0013] (composition) 1 shows an example of a cruise control device according to this embodiment. Vehicle 1 includes cruise control device 10 and a controlled object 20. Cruise control device 10 includes a path following controller 11, a disturbance suppression controller 12, a deceleration controller 13, an odometry 14, and a self-position estimator 15. Control object 20 includes a vehicle body 21, a drive system 22, and a steering system 23.

[0014] The airframe 21 includes the wheels, body, and sensors of the vehicle 1. The sensors of the vehicle 1 include an inertial measurement unit (IMU), a tire rotation counter, a steering angle sensor, and the like. The drive system 22 includes a vehicle speed controller 221 and a drive motor 222. The vehicle speed controller 221 is, for example, a PI (proportional-integral) controller. The vehicle speed controller 221 calculates the rotation speed of the wheels that brings the deviation between the target speed V output by the cruise control device 10 and the actual speed of the vehicle 1 closer to zero, and drives the drive motor 222 at that rotation speed. The drive motor 222 rotates the wheels at the rotation speed calculated by the vehicle speed controller 221. The steering system 23 includes a steering motor 231 that controls the direction of the wheels. The steering system 23 controls the steering motor 231 in accordance with the steering angle command δ output by the cruise control device 10 to change the direction of the wheels.

[0015] The path tracking controller 11 acquires a predetermined target trajectory, a speed profile, and position information of the vehicle 1 estimated by the self-position estimator 15, and calculates a target speed V' and a steering angle command δ' for moving the vehicle 1 along the target trajectory. A known path tracking controller can be used for the path tracking controller 11. For example, a target speed is defined for each predetermined position along the target trajectory in the speed profile, and the path tracking controller 11 acquires the target speed in the position information of the vehicle 1 estimated by the self-position estimator 15 by referring to the speed profile and outputs the value as the target speed V'. Furthermore, for example, as disclosed in Patent Document 1, the path tracking controller 11 acquires the curvature of the target trajectory at a point where the vehicle 1 will travel in Δt seconds by referring to the target trajectory, and calculates a steering angle command δ' based on the vehicle speed at that point and predetermined vehicle motion characteristics.

[0016] The disturbance reduction controller 12 calculates a corrected steering angle Δδ' based on the azimuth angle deviation of the vehicle 1, using a kinematic model for when the vehicle 1 runs without slipping and the steering system as a reference model. The disturbance reduction controller 12 acquires the actual steering angle δa output from the steering system 23 to the airframe 21. Alternatively, the disturbance reduction controller 12 calculates the actual steering angle δa from the steering angle command δ using the following equation (1), which approximates the operational delay of the steering motor 231 and the like in the steering system 23 with a first-order delay system. δa=1 / (T a s+1)×δ (1) Here, T a is a time constant representing the delay of the steering motor 231 etc. provided in the steering system 23, and s is a Laplace operator. The disturbance reduction controller 12 substitutes the acquired actual steering angle δa into the following equation (2) to calculate the ideal azimuth angular velocity r^ corresponding to the actual steering angle δa. r^=V / W×tan(δa) (2) Here, V is the speed of vehicle 1 (target speed V, described later), and W is the wheelbase length. The wheelbase length is the distance between the front and rear wheels of vehicle 1 (W in FIG. 3). The azimuth angular velocity is the change in the traveling direction of vehicle 1 per unit time, as shown in FIG. 2. For example, if vehicle 1 is traveling in the direction of arrow 1a in FIG. 2(a) at a certain time, and T seconds later it is traveling in the direction of arrow 1b, and the angle between arrows 1a and 1b is θ, the azimuth angular velocity of vehicle 1 during this time is θ / T (rad / s). Furthermore, equation (2) is a kinematics model 122 for traveling without slip based on the azimuth angle deviation of vehicle 1. The kinematics model 122 is a relatively simple model that does not take into account tire slippage or wheel spin, and represents the relationship between traveling speed V, steering angle δa, and azimuth angular velocity r^. Since the kinematics model 122 of equation (2) is publicly known, a description of how it is derived will be omitted.

[0017] The disturbance suppression controller 12 acquires the azimuth angular velocity r of the vehicle 1 measured by the inertial navigation system provided in the vehicle 1, and calculates the value r_ obtained by removing high-frequency noise components using a low-pass filter 121, and the ideal azimuth angular velocity r_ calculated by equation (2). v The deviation Δr is calculated by the following equation (3) using a subtractor 125. Δr=r_-rv ····(3)

[0018] Next, the disturbance reduction controller 12 inputs Δr to the corrective steering angle calculator 123 to calculate the corrective steering angle Δδ. The corrective steering angle calculator 123 calculates the corrective steering angle Δδ using Δr and the following equation (4) obtained by modifying the above equation (2). Δδ=tan -1 (W Δr / V) (4)

[0019] The disturbance reduction controller 12 compensates for the corrective steering angle Δδ using the lag-lead compensator 124 and outputs the corrective steering angle Δδ' after compensation. The corrective steering angle Δδ' is calculated by the following equation (5). Δδ´={(T a s+1) / (T d s+1)}×Δδ (5) T a is a time constant representing the operation delay of the steering motor 231, etc., and T d is a time constant representing a frequency band for cutting off high frequency components, and s is a Laplace operator. Using equation (5), it is possible to calculate a corrected steering angle Δδ' that removes high frequency components and compensates (advances) the operational delay of the steering motor 231, etc.

[0020] The cruise control device 10 calculates the deviation between the steering angle δ' output by the path tracking controller 11 and the corrected steering angle Δδ' after compensation output by the disturbance reduction controller 12 using the following equation (6) using a subtractor 17 to calculate a steering angle command δ. The cruise control device 10 outputs (commands) the steering angle command δ. δ = δ´-Δδ´ (6) By feeding back the corrected corrective steering angle Δδ' to the steering angle command δ' output by the path following controller 11, it is possible to compensate for slippage of the vehicle 1 and other noises as disturbances collectively, and it is possible to calculate a target steering angle δ that cancels out the influence of the disturbances and follows the target path.

[0021] The deceleration controller 13 includes a risk calculator 131 and a deceleration calculator 132. The risk calculator 131 calculates the forward speed v measured by the inertial navigation system of the vehicle 1. x , sideslip velocity vy The risk of rollover is calculated based on the lateral load transfer ratio (LTR) from the azimuth speed r.

[0022] The method of calculating the LTR will be described with reference to Fig. 3. Fig. 3 shows an example of the vehicle body when the vehicle 1 is an AGF (Automated Guided Forklift). Fig. 3(a) shows the vehicle 1 as seen from the front, and Fig. 3(b) shows a side view of the vehicle 1. The vehicle 1 has a front wheel 21a and rear wheels 21b and 21c. The load on the front wheel 21a is expressed as W f The loads on the rear wheels 21b and 21c are W1 and W2, respectively. In this case, the LTR can be calculated using the following equation (7). LTR=(W1-W2) / (W1+W2) ····(7) LTR is the ratio of the load on the left and right wheels of vehicle 1, and when LTR exceeds ±1 (where one wheel is lifted) (or when LTR approaches ±1), vehicle 1 becomes more likely to roll over.

[0023] The direction of travel of vehicle 1 is the x-axis, the horizontal direction perpendicular to the direction of travel is the y-axis, and the vertical direction is the z-axis. The weight of vehicle 1 is m, and the speed in the x-axis direction is v. x , the velocity in the y-axis direction (velocity in the sideslip direction) is v y , gravity is g, the distance from the center of gravity of the vehicle 1 to the rear wheels 21b and 21c is l r , the distance from the center of gravity of the vehicle 1 to the ground is h, the distance from the center of gravity of the vehicle 1 to the front wheel 21a is l f The distance between the left and right rear wheels is defined as T. Then, the following three equations (8) to (10) hold true.

[0024] (1 / 2)·(W1-W2)=hmv y r (8) l r (W1+W2)=hmv x · +l f W f ····(9) (v x · denotes the acceleration of vehicle 1 in the x direction.) W f+W1+W2=mg (10)

[0025] By solving equations (8) to (10) for W1 and W2 and substituting them into equation (7), the following equation (11) is obtained. LTR=(W1-W2) / (W1+W2) =(2h / Tg) (lr / lf) v x ·r ····(11) Furthermore, the risk calculator 131 calculates the velocity v in the y-axis direction. y from acceleration v y · and calculate the rollover risk R expressed by the following equation (12).

[0026]

number

[0027] The deceleration calculator 132 calculates the deceleration V breaking Calculate.

[0028]

number

[0029] That is, the deceleration calculator 132 determines whether the absolute value of the rollover risk R is greater than a predetermined threshold value R^, and if the absolute value of the rollover risk R is greater than the predetermined threshold value R^, the deceleration calculator 132 calculates the deceleration v breaking is calculated using the following equation (14). V breaking = k R (|R|-R^) (14) where k R is a coefficient for converting the dimensionless (|R|-R^) into a velocity (m / s), and its magnitude is determined in advance through experiments, simulations, etc. The magnitude of the threshold value R^ is a value less than 1 (for example, 0.5). When the absolute value of the rollover risk R is equal to or less than the predetermined threshold value R^, the deceleration calculator 132 converts the deceleration v breaking Calculate 0 as follows.

[0030] The travel control device 10 calculates the speed V' calculated by the path tracking controller 11 and the deceleration V calculated by the deceleration calculator 132. breaking and a subtractor 16 to calculate the target speed V according to the following equation (15): The cruise control device 10 outputs (commands) the target speed V to the controlled object. V = V´ - V breaking ····(15) When the rollover risk R exceeds the threshold value R^, deceleration control is performed to prevent the vehicle 1 from rolling over.

[0031] The odometry 14 calculates the amount of movement (movement distance, movement direction) of the vehicle 1 by integrating the number of rotations of the wheels measured by the tire rotation counter and the total steering angle measured by the steering angle sensor. The self-position estimator 15 adds the amount of movement of the vehicle 1 calculated by the odometry 14 to the initial position of the vehicle 1 to estimate the position information of the vehicle 1. The self-position estimator 15 outputs the estimated position information to the path following controller 11.

[0032] (operation) Next, the operation of the driving control device 10 will be described. FIG. 4 is a diagram illustrating an example of a process for calculating a vehicle speed according to the embodiment. The cruise control device 10 acquires a command value for the speed of the vehicle 1 (step S1). For example, the cruise control device 10 acquires the speed V' calculated by the path tracking controller 11. Next, the risk calculator 131 calculates the rollover risk R (step S2). The risk calculator 131 calculates the speed v' in the traveling direction from a sensor such as an inertial navigation system provided in the vehicle 1. x , horizontal velocity v perpendicular to the direction of travel y , the azimuth angular velocity r is acquired, and the rollover risk R is calculated by the formula (12). Next, the deceleration calculator 132 calculates the deceleration V breaking (Step S3). The deceleration calculator 132 compares the rollover risk R with the threshold value R^ and calculates the deceleration v breaking Next, the cruise control device 10 calculates the target speed V (step S4). The cruise control device 10 uses the subtractor 16 to subtract the deceleration v from the speed command value (for example, V'). breakingThe cruise control device 10 calculates the target speed V of the vehicle 1 by subtracting the above.

[0033] FIG. 5 shows an example of speed change when the target speed is corrected by deceleration and when the correction is not performed. FIG. 5 is a diagram showing an example of the effect of deceleration control according to the embodiment. FIG. 5(a) shows the change over time in the rollover risk R of a traveling vehicle 1, and FIG. 5(b) shows the change over time in the speed of the vehicle 1. The vehicle 1 is traveling on a route that includes a curve, and the data shown in FIG. 5 are the rollover risk R and the speed when the vehicle turns the curve around time T1. In FIG. 5(a), the graph r1 shows the deceleration v breaking The graph r2 shows the rollover risk R when deceleration is not performed by the breaking In Fig. 5(b), the graph v1 shows the rollover risk R when the vehicle is decelerated by the deceleration v breaking The graph v2 shows the speed of vehicle 1 when no deceleration is performed by the breaking As shown in the figure, the deceleration v breaking If the vehicle 1 does not decelerate (graphs r1 and v1), the vehicle 1 will turn the curve without decelerating, and the rollover risk R will exceed 1, causing the vehicle 1 to roll over. breaking When deceleration is performed according to the LTR (graphs r2 and v2), the vehicle 1 can turn the curve while decelerating and travel without overturning. In this way, by controlling the deceleration of the vehicle 1 according to the rollover risk R based on the LTR, the risk of the vehicle 1 overturning can be reduced, for example, even when a sudden steering operation is performed.

[0034] FIG. 6 is a diagram illustrating an example of a calculation process of the steering angle according to the embodiment. The cruise control device 10 acquires a command value for the steering angle of the vehicle 1 (step S11). For example, the cruise control device 10 acquires a steering angle command δ' calculated by the path tracking controller 11. Next, the disturbance reduction controller 12 calculates a corrective steering angle Δδ' (step S12). The disturbance reduction controller 12 calculates an ideal azimuth angular velocity r (when no skidding or the like occurs in the vehicle 1) using the actual steering angle δa and the kinematics model 122.v The disturbance attenuation controller 12 calculates the azimuth angular velocity r and the azimuth angular velocity r of the vehicle 1 from which noise has been removed by the low-pass filter 121. v The deviation between the steering motor 231 and the steering angle command δ' is calculated using the subtractor 125, and a corrective steering angle Δδ that compensates for this deviation is calculated using the corrective steering angle calculator 123. The disturbance reduction controller 12 performs compensation using the lag-lead compensator 124 to advance the corrective steering angle Δδ by an amount corresponding to the delay of the steering motor 231, etc., and to block high-frequency components, and outputs the corrected corrective steering angle Δδ' to the subtractor 17. Next, the cruise control device 10 calculates a target steering angle (step S13). The cruise control device 10 uses the subtractor 17 to subtract the corrective steering angle Δδ' from the steering angle command δ' to calculate a target steering angle (steering angle command δ) of the vehicle 1. The cruise control device 10 outputs the target steering angle to the steering system 23.

[0035] FIG. 7 shows examples of the travel trajectories of the vehicle 1 when the steering angle is corrected by the disturbance attenuation controller 12 and when it is not corrected. FIG. 7 is a diagram illustrating an example of the effect of disturbance attenuation control according to the embodiment. The dashed line p0 in FIG. 7 indicates the target trajectory of the vehicle 1, where the vehicle 1 travels in the positive direction of the x-axis as indicated by arrow 7a, turns a curve, and travels in the positive direction of the y-axis as indicated by arrow 7b. Line p1 shows the trajectory of the vehicle 1 when the steering angle is not corrected, and line p2 shows the trajectory of the vehicle 1 when the steering angle is corrected. As shown in the figure, when the steering angle is corrected, the amount of meandering on a straight road after turning a curve can be reduced compared to when the steering angle is not corrected. In other words, the ability to follow the target route can be improved. This is the effect achieved by the disturbance attenuation controller 12 steering so as to quickly converge the deviation in azimuth angular velocity due to the influence of the curve.

[0036] 4 and 6 while the vehicle 1 is traveling. In the above embodiment, the path following controller 11 calculates the desired speed V' and total steering angle δ', but the speed V' of the vehicle 1 corrected by the deceleration controller 13 and the steering angle δ' corrected by the disturbance reduction controller 12 may be values ​​determined by input from the driver of the vehicle 1.

[0037] (effect) As described above, according to this embodiment, even when a sharp steering operation is performed, rollover can be prevented by decelerating the vehicle 1 based on the rollover risk level R. Furthermore, without identifying the cause of the azimuth angle deviation of the vehicle 1, the corrective steering angle Δδ' is calculated based on the deviation between the ideal azimuth angular velocity and the measured azimuth angular velocity, and this value is fed back, thereby suppressing deviation of the vehicle 1 from the target route. As a result, even when a sharp steering operation is performed when turning a curve, for example, the vehicle can turn the curve without rollover and continue traveling while suppressing deviation from the target route. Furthermore, even when the vehicle 1 runs over a curb or the like while traveling straight, for example, by quickly detecting changes in speed and azimuth angular velocity and performing correction of the steering angle by the disturbance suppression controller 12 and deceleration control based on the rollover risk level R, deviation of the vehicle 1 from the target route can be suppressed and the risk of rollover can be reduced. Furthermore, according to this embodiment, the vehicle can detect and decelerate the vehicle 1 based on the sensor (v x , v y , r are usually mounted on vehicles. Since disturbance suppression control and deceleration control can be performed using the sensors, there is no need to add a new sensor for the control of this embodiment.

[0038] The above-described cruise control device 10 is implemented in a computer including a processor such as a CPU (Central Processing Unit), a main storage device, an auxiliary storage device, etc., and each of the above-described functions is realized by the processor executing a program stored in the auxiliary storage device. The processor allocates a storage area in the main storage device in accordance with the program. The processor allocates a storage area in the auxiliary storage device in accordance with the program for storing data being processed. Note that some or all of the processes of the cruise control device 10 may be executed by hardware such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array).

[0039] In addition, the components in the above-described embodiments can be replaced with well-known components as appropriate without departing from the spirit of the present invention. Furthermore, the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0040] <Additional Notes> The cruise control device, vehicle, cruise control method, and program described in each embodiment can be understood, for example, as follows.

[0041] (1) The cruise control device 10 according to the first aspect calculates the speed (v x ) and the horizontal velocity of the vehicle (v y ), a risk calculation unit (risk calculator 131) that acquires the azimuth angular velocity (r) of the vehicle and calculates a rollover risk based on the LTR (Lateral Load Transfer Ratio) of the vehicle, and a deceleration v that indicates the degree to which the speed in the traveling direction is to be decelerated when the absolute value of the rollover risk exceeds a threshold value. breakingand a control unit that controls the drive system of the vehicle by reducing the target speed (V') of the vehicle based on the deceleration to a new target speed (V). This makes it possible to prevent the vehicle from overturning. For example, when an external disturbance (such as going over a curve or a curb) is too great, the vehicle may be operated abruptly relative to the traveling speed, which may cause a forklift with a high center of gravity to overturn. However, according to this embodiment, the risk of overturning can be reduced.

[0042] (2) A driving control device 10 according to a second aspect is the driving control device 10 of (1), in which the risk calculation unit calculates the rollover risk by multiplying the value obtained by multiplying the speed in the direction of travel by the azimuth angular velocity and adding the acceleration in the horizontal direction to the value, by a predetermined coefficient (equation (12)). This allows the vehicle's forward speed (v x ) and the horizontal velocity of the vehicle (v y ) and the azimuth angular velocity (r), the rollover risk R based on the LTR of the vehicle can be calculated.

[0043] (3) The driving control device 10 according to the third aspect is the driving control device 10 of (1) to (2), and the deceleration calculation unit (deceleration calculator 132) calculates the deceleration by multiplying the difference between the absolute value of the rollover risk and a threshold value by a predetermined coefficient (equation (13)). This reduces the deceleration v that prevents the vehicle from rolling over. breaking can be calculated.

[0044] (4) The cruise control device 10 according to a fourth aspect is the cruise control device 10 according to any one of (1) to (3), and is configured to calculate an ideal value (r vand a corrective steering angle calculation unit that calculates a corrective steering angle (Δδ') based on the deviation between the target steering angle and the measured value of the azimuth angular velocity (r), and the control unit controls the steering system of the vehicle by using a value obtained by subtracting the corrective steering angle from the target steering angle as the new target steering angle. This makes it possible to control the running of the vehicle based on the steering angle that compensates for the influence of disturbances that affect the azimuth angular velocity. Also, when compensating for vehicle slippage, if a sudden operation is performed, a vehicle traveling at high speed may roll over, but the configurations of the first to third aspects make it possible to perform disturbance compensation while avoiding rollover.

[0045] (5) A vehicle according to a fifth aspect includes the cruise control device according to any one of (1) to (4). This allows the vehicle to be equipped with a rollover prevention function.

[0046] (6) A cruise control method according to a sixth aspect includes the steps of: acquiring the speed of the vehicle in the direction of travel, the speed of the vehicle in a horizontal direction perpendicular to the direction of travel, and the azimuth angular velocity of the vehicle, and calculating a rollover risk based on the LTR (Lateral Load Transfer Ratio) of the vehicle; if the absolute value of the rollover risk exceeds a threshold value, calculating a deceleration indicating the degree to which the speed in the direction of travel should be reduced; and controlling the drive system of the vehicle by reducing the target speed of the vehicle based on the deceleration to a value that is set as the new target speed.

[0047] (7) A program according to a seventh aspect causes a computer to execute the steps of: acquiring the speed of the vehicle in the direction of travel, the speed of the vehicle in a horizontal direction perpendicular to the direction of travel, and the azimuth angular velocity of the vehicle, and calculating a rollover risk based on the LTR (Lateral Load Transfer Ratio) of the vehicle; if the absolute value of the rollover risk exceeds a threshold, calculating a deceleration indicating the degree to which the speed in the direction of travel should be decelerated; and calculating a value obtained by decelerating the target speed of the vehicle based on the deceleration as the new target speed. [Explanation of symbols]

[0048] 1 Vehicle, 10 Cruise control device, 11 Path tracking controller, 12 Disturbance rejection controller, 13 Deceleration controller, 14 Odometry, 15 Self-position estimator, 20 Controlled object, 21 Airframe, 22 Drive system, 221 Vehicle speed controller, 222 Drive motor, 23 Steering system, 231 Steering motor, 121 Low-pass filter, 122 Kinematics model, 123 Corrected steering angle calculator, 124 Lead-lag compensator, 131 Risk calculator, 132 Deceleration calculator, 21a Front wheels, 21b Rear wheels, 21c Rear wheels

Claims

1. a risk calculation unit that acquires a speed of the vehicle in a traveling direction, a speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and an azimuth angular velocity of the vehicle, and calculates a rollover risk based on an LTR (Lateral Load Transfer Ratio) of the vehicle; a deceleration calculation unit that calculates a deceleration indicating a degree of deceleration of the speed in the traveling direction when the absolute value of the rollover risk exceeds a threshold value; a control unit that controls a drive system of the vehicle by setting a value obtained by reducing a target speed of the vehicle based on the deceleration as a new target speed; and the deceleration calculation unit calculates the deceleration by multiplying a difference between the absolute value of the rollover risk and a threshold value by a predetermined coefficient. Driving control device.

2. a risk calculation unit that acquires a speed of the vehicle in a traveling direction, a speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and an azimuth angular velocity of the vehicle, and calculates a rollover risk based on an LTR (Lateral Load Transfer Ratio) of the vehicle; a deceleration calculation unit that calculates a deceleration indicating a degree of deceleration of the speed in the traveling direction when the absolute value of the rollover risk exceeds a threshold value; a control unit that controls a drive system of the vehicle by setting a value obtained by reducing a target speed of the vehicle based on the deceleration as a new target speed; a corrective steering angle calculation unit that calculates a corrective steering angle based on a deviation between an ideal value of the azimuth angular velocity, which is calculated based on a kinematic model that represents the relationship between the speed in the traveling direction of the vehicle, the steering angle, and the azimuth angular velocity of the vehicle, and an actual steering angle of the vehicle, and the measured value of the azimuth angular velocity; and the control unit controls a steering system of the vehicle by setting a value obtained by subtracting the corrected steering angle from the target steering angle as the new target steering angle. Driving control device.

3. the risk calculation unit calculates the rollover risk by multiplying the speed in the traveling direction by the azimuth angular velocity and the acceleration in the horizontal direction by a predetermined coefficient. The driving control device according to claim 1 or 2.

4. A vehicle comprising the cruise control device according to any one of claims 1 to 3.

5. A step in which a driving control device acquires the speed of the vehicle in the direction of travel, the speed of the vehicle in a horizontal direction perpendicular to the direction of travel, and the azimuth angular velocity of the vehicle, and calculates the risk of rollover based on the LTR (Lateral Load Transfer Ratio) of the vehicle; a step of calculating a deceleration indicating a degree of deceleration of the speed in the traveling direction when the absolute value of the rollover risk exceeds a threshold value; a step in which the cruise control device controls a drive system of the vehicle by setting a value obtained by reducing the target speed of the vehicle based on the deceleration as the new target speed; and In the step of calculating the deceleration, the driving control device calculates the deceleration by multiplying a difference between an absolute value of the rollover risk and a threshold value by a predetermined coefficient. Driving control method.

6. A step in which a driving control device acquires the speed of the vehicle in the direction of travel, the speed of the vehicle in a horizontal direction perpendicular to the direction of travel, and the azimuth angular velocity of the vehicle, and calculates the risk of rollover based on the LTR (Lateral Load Transfer Ratio) of the vehicle; a step of calculating a deceleration indicating a degree of deceleration of the speed in the traveling direction when the absolute value of the rollover risk exceeds a threshold value; a step in which the cruise control device calculates a corrective steering angle based on a deviation between an ideal value of the azimuth angular velocity calculated based on a kinematic model representing the relationship between the speed in the traveling direction of the vehicle, the steering angle, and the azimuth angular velocity of the vehicle, and an actual steering angle of the vehicle, and the measured value of the azimuth angular velocity; a step in which the cruise control device controls a drive system of the vehicle by setting a value obtained by reducing the target speed of the vehicle based on the deceleration as the new target speed; a step in which the driving control device controls a steering system of the vehicle by setting a value obtained by subtracting the corrected steering angle from a target steering angle as a new target steering angle; A driving control method comprising:

7. On the computer, a step of acquiring a speed of the vehicle in a traveling direction, a speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and an azimuth angular velocity of the vehicle, and calculating a rollover risk based on an LTR (Lateral Load Transfer Ratio) of the vehicle; When the absolute value of the rollover risk exceeds a threshold, calculating a deceleration indicating a degree of deceleration of the speed in the traveling direction; a step of calculating a value obtained by reducing the target speed of the vehicle based on the deceleration as a new target speed; and In the step of calculating the deceleration, a process of calculating the deceleration by multiplying a difference between the absolute value of the rollover risk and a threshold value by a predetermined coefficient; A program that executes the following.

8. On the computer, a step of acquiring a speed of the vehicle in a traveling direction, a speed of the vehicle in a horizontal direction perpendicular to the traveling direction, and an azimuth angular velocity of the vehicle, and calculating a rollover risk based on an LTR (Lateral Load Transfer Ratio) of the vehicle; When the absolute value of the rollover risk exceeds a threshold, calculating a deceleration indicating a degree of deceleration of the speed in the traveling direction; calculating a corrective steering angle based on a deviation between an ideal value of the azimuth angular velocity, which is calculated based on a kinematic model representing the relationship between the speed in the traveling direction of the vehicle, the steering angle, and the azimuth angular velocity of the vehicle, and an actual steering angle of the vehicle; and a step of calculating a value obtained by reducing the target speed of the vehicle based on the deceleration as a new target speed; a step of controlling a steering system of the vehicle using a value obtained by subtracting the corrected steering angle from a target steering angle as a new target steering angle; A program that executes the following.

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