AEB brake control method for deceleration closed-loop control of motor torque

Abstract

The invention relates to an AEB braking control method for deceleration closed-loop control of motor torque, which comprises the following steps of: calculating a braking distance of safe braking of a vehicle according to position information of an obstacle on a driving path and an expected braking position of the vehicle; calculating the target deceleration of the vehicle according to the current actual vehicle speed, the obstacle speed and the braking distance of the vehicle; on the basis of the difference value between the actual deceleration of the vehicle and the braking target deceleration, the deceleration needed by motor compensation braking is calculated, and a threshold value for starting calculation of the accumulated motor torque is set; on the basis of the deceleration of motor compensation braking, the road sliding resistance and the actual road slope information, the torque amount of a feed-forward motor of vehicle motor compensation braking is calculated; calculating a difference value between the vehicle actual deceleration after motor compensation and the vehicle braking target deceleration, and when the difference value is smaller than a set threshold value, calculating an accumulated motor torque amount; accumulating the feedforward motor torque amount and the accumulated motor torque amount to update the motor output torque, and controlling the vehicle to brake according to the current motor output torque. By the adoption of the technical scheme, the AEB braking control method for the deceleration closed-loop control motor torque is provided, in the driving process, precise control over the braking distance is achieved through the deceleration closed-loop control motor torque, and then safe braking of a vehicle is achieved.

Description

Technical Field

[0001] The present invention relates to the field of intelligent assisted driving technology, and in particular to an AEB braking control method based on deceleration closed-loop control of motor torque. Background Art

[0002] With the development of intelligent assisted driving technology, driving safety issues are becoming increasingly important in the driving field. Active safety technologies can greatly ensure the safety of vehicles during driving. By avoiding vehicle collisions through active safety, it can provide safety protection for drivers and vulnerable road users, further improve the safety performance of vehicles, and reduce traffic accidents and loss of life and property.

[0003] In order to ensure the safety of vehicle driving to the greatest extent, the automatic emergency braking function (AEB) is an effective solution to reduce vehicle collision accidents.

[0004] In relevant AEB technical solutions, the AEB triggering process relies heavily on the performance of the chassis actuator. If the chassis performance cannot support drastic changes in deceleration or the execution delay is too high, the vehicle will not be able to stop in time after the AEB function is activated, resulting in a collision. This will cause a major safety hazard if the collision cannot be avoided. Summary of the Invention

[0005] Purpose of the present invention: In order to overcome the defects of the prior art, the present invention provides an AEB braking control method with a deceleration closed-loop control of the motor torque, so that during driving, the braking distance can be accurately controlled by controlling the deceleration closed-loop control of the motor torque, thereby achieving safe braking of the vehicle.

[0006] The technical solution of the present invention is an AEB braking control method for controlling motor torque by closed-loop deceleration, comprising:

[0007] Confirm the target deceleration rate of the vehicle after AEB is activated;

[0008] Calculate the braking distance required for the vehicle to stop safely based on the location of obstacles in the driving path and the vehicle's desired braking position;

[0009] Calculate the target deceleration of the vehicle based on the vehicle's current actual speed, obstacle speed, and braking distance;

[0010] Based on the difference between the vehicle's actual deceleration and the target deceleration for braking, the deceleration required for motor compensation braking is calculated, and a threshold for starting to calculate the cumulative motor torque is set.

[0011] After the chassis braking deceleration reaches a steady state, the motor compensating braking deceleration is updated based on the difference between the vehicle's actual deceleration and the target deceleration;

[0012] Calculating the feedforward motor torque of the vehicle motor compensatory braking based on the deceleration of the motor compensatory braking, the road sliding resistance and the actual road slope information;

[0013] Calculate the difference between the actual vehicle deceleration after motor compensation and the target vehicle braking deceleration. When the difference is less than the set threshold, calculate the cumulative motor torque.

[0014] The feedforward motor torque and the accumulated motor torque are accumulated to update the motor output torque, and the vehicle is braked according to the current motor output torque.

[0015] Further settings include:

[0016] A perception information acquisition module is used to acquire and output obstacle position information, obstacle speed information, and obstacle acceleration information on the driving path;

[0017] Driving parameter acquisition module, used to obtain and output the actual speed and acceleration information of the vehicle;

[0018] The target deceleration compensation calculation module calculates the target compensation deceleration required for motor braking based on the sensing information and driving parameters;

[0019] The motor brake feedforward torque calculation module calculates the motor feedforward compensation torque based on the target deceleration required for motor braking;

[0020] The motor brake closed-loop torque calculation module calculates the motor brake closed-loop torque required to eliminate the error between the vehicle's target deceleration and actual deceleration;

[0021] The vehicle brake control execution module is used to execute the motor brake torque control command to control the vehicle to stop.

[0022] It is further provided that the calculating of the braking distance for the vehicle to stop safely based on the position information of the obstacle in the driving path and the expected braking position of the vehicle includes:

[0023] The relative distance between the vehicle and the obstacle is calculated based on the obstacle position information on the driving path output by the perception information acquisition module, and the safe braking distance of the vehicle is obtained by subtracting the vehicle's expected braking position from the current relative distance.

[0024] Further settings are made to calculate the target deceleration of the vehicle based on the vehicle's current actual speed, obstacle speed, and braking distance, including:

[0025] The target deceleration calculation formula is input based on the vehicle's current actual speed and acceleration output by the driving parameter acquisition module, the obstacle speed output by the perception information acquisition module, and the braking distance value.

[0026] The target deceleration calculation formula for the vehicle braking includes: a goal is the target deceleration of the vehicle, x brk is the vehicle's braking distance, v real is the relative speed between the vehicle and the obstacle, and the calculation formula is v real =v ego -v obj , where v ego is the vehicle speed, v obj is the obstacle speed.

[0027] Furthermore, the deceleration of the motor compensation brake, the road sliding resistance and the actual road slope information are input into the motor torque calculation formula FF = mΔar-(Av 2 +Bv+C)r-mgsinθ*r,

[0028] Where mΔar is the torque required for the motor to implement the target deceleration, m is the vehicle weight, r is the tire dynamic radius of the vehicle, Δa is the deceleration required for motor braking, Av 2 +Bv+C is the road sliding resistance, A, B, and C are the fitted vehicle resistance coefficients respectively. If the current actual vehicle speed is 0, C is the static friction resistance value. If the current actual vehicle speed is greater than 0, C is the dynamic friction resistance value. v is the current actual vehicle speed, mgsinθ is the slope resistance compensation, g is the acceleration of gravity, and θ is the actual road slope.

[0029] It is further configured that the difference between the actual deceleration of the vehicle and the target deceleration of the vehicle braking is input into the PID controller to calculate the motor cumulative torque, and the motor cumulative torque and the motor feedforward torque are accumulated to update the motor output torque to control the vehicle to brake.

[0030] By adopting the above technical solution, the motor output torque is obtained by adding the torque feedforward amount and the cumulative torque amount of the vehicle, and the vehicle is braked according to the motor output torque, thereby realizing closed-loop control of deceleration during the AEB process. Based on the closed-loop control of deceleration, the braking distance is precisely controlled, thereby avoiding the vehicle collision caused by failure to brake after AEB is activated. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of the control method of the present invention;

[0032] Figure 2 A block diagram of each module of the present invention;

[0033] Figure 3 Schematic diagram of the calculation steps of the motor torque of the present invention. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in this embodiment with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0035] like Figure 1-3 As shown, an AEB braking control method for deceleration closed-loop control of motor torque includes:

[0036] Confirm the target deceleration rate of the vehicle after AEB is activated;

[0037] Calculate the braking distance required for the vehicle to stop safely based on the location of obstacles in the driving path and the vehicle's desired braking position;

[0038] Calculate the target deceleration of the vehicle based on the vehicle's current actual speed, obstacle speed, and braking distance;

[0039] After the chassis braking deceleration reaches a steady state, the motor compensating braking deceleration is updated based on the difference between the vehicle's actual deceleration and the target deceleration;

[0040] Based on the difference between the vehicle's actual deceleration and the target deceleration for braking, the deceleration required for motor compensation braking is calculated, and a threshold for starting to calculate the cumulative motor torque is set.

[0041] If the deceleration of the motor compensation brake is ≥0, the motor output torque is 0, and the vehicle can be controlled to stop at this time;

[0042] If the deceleration of the motor compensation braking is less than 0, the next step is to calculate the feedforward motor torque of the vehicle motor compensation braking based on the deceleration of the motor compensation braking, the road sliding resistance and the actual road slope information;

[0043] Calculate the difference between the actual vehicle deceleration after motor compensation and the target vehicle braking deceleration. When the difference is less than the set threshold, calculate the cumulative motor torque.

[0044] Accumulate the feedforward motor torque and the accumulated motor torque to update the motor output torque, and control the vehicle to stop according to the current motor output torque;

[0045] When the difference is greater than or equal to the set threshold, the feedforward motor torque and the accumulated motor torque are directly accumulated to update the motor output torque, and the vehicle is controlled to stop according to the current motor output torque.

[0046] Further settings include:

[0047] A perception information acquisition module is used to acquire and output obstacle position information, obstacle speed information, and obstacle acceleration information on the driving path;

[0048] Driving parameter acquisition module, used to obtain and output the actual speed and acceleration information of the vehicle;

[0049] The target deceleration compensation calculation module calculates the target compensation deceleration required for motor braking based on the sensing information and driving parameters;

[0050] A motor brake feedforward torque calculation module calculates the motor feedforward compensation torque based on the target compensation deceleration required for motor braking;

[0051] The motor brake closed-loop torque calculation module calculates the motor brake closed-loop torque required to eliminate the error between the vehicle's target deceleration and actual deceleration;

[0052] The vehicle brake control execution module is used to execute the motor brake torque control command to control the vehicle to brake. The information obtained by the perception information acquisition module and the driving parameter acquisition module is output to the target deceleration compensation calculation module to calculate the target compensation deceleration required for motor braking, and the calculated value is transmitted to the motor brake feedforward torque calculation module and the motor brake closed-loop torque calculation module to calculate the motor feedforward compensation torque and the motor brake closed-loop torque. The vehicle brake control execution module accumulates the motor feedforward compensation torque and the accumulated motor torque to update the motor output torque, and controls the vehicle to brake according to the current motor output torque.

[0053] It is further provided that the calculating of the braking distance for the vehicle to stop safely based on the position information of the obstacle in the driving path and the expected braking position of the vehicle includes:

[0054] The relative distance between the vehicle and the obstacle is calculated based on the obstacle position information on the driving path output by the perception information acquisition module, and the safe braking distance of the vehicle is obtained by subtracting the vehicle's expected braking position from the current relative distance.

[0055] Further settings are made to calculate the target deceleration of the vehicle based on the vehicle's current actual speed, obstacle speed, and braking distance, including:

[0056] The target deceleration calculation formula is input based on the vehicle's current actual speed and acceleration output by the driving parameter acquisition module, the obstacle speed output by the perception information acquisition module, and the braking distance value.

[0057] The target deceleration calculation formula for the vehicle braking is: a goal is the target deceleration of the vehicle, x brk is the vehicle's braking distance, v realis the relative speed between the vehicle and the obstacle, and the calculation formula is v real =v ego -v obj , where v ego is the vehicle speed, v obj is the obstacle speed.

[0058] Furthermore, the deceleration of the motor compensation brake, the road sliding resistance and the actual road slope information are input into the motor torque calculation formula FF = mΔar-(Av 2 +Bv+C)r-mgsinθ*r,

[0059] Where mΔar is the torque required for the motor to implement the target deceleration, m is the vehicle weight, r is the tire dynamic radius of the vehicle, Δa is the deceleration required for motor braking, Av 2 +Bv+C is the road sliding resistance, A, B, and C are the fitted vehicle resistance coefficients respectively. If the current actual vehicle speed is 0, C is the static friction resistance value. If the current actual vehicle speed is greater than 0, C is the dynamic friction resistance value. v is the current actual vehicle speed, mgsinθ is the slope resistance compensation, g is the acceleration of gravity, and θ is the actual road slope.

[0060] It is further configured that the difference between the actual deceleration of the vehicle and the target deceleration of the vehicle braking is input into the PID controller to calculate the motor cumulative torque, and the motor cumulative torque and the motor feedforward torque are accumulated to update the motor output torque to control the vehicle to brake.

[0061] By adopting the above technical solution, the motor output torque is obtained by adding the torque feedforward amount and the cumulative torque amount of the vehicle, and the vehicle is braked according to the motor output torque, thereby realizing closed-loop control of deceleration during the AEB process. Based on the closed-loop control of deceleration, the braking distance is precisely controlled, thereby avoiding the vehicle collision caused by failure to brake after AEB is activated.

Claims

1. An AEB braking control method for deceleration closed-loop control of motor torque, characterized in that: include: Confirm the target deceleration rate of the vehicle after AEB is activated; Calculate the braking distance required for the vehicle to stop safely based on the location of obstacles in the driving path and the vehicle's desired braking position; Calculate the target deceleration of the vehicle based on the vehicle's current actual speed, obstacle speed, and braking distance; Based on the difference between the vehicle's actual deceleration and the target deceleration for braking, the deceleration required for motor compensation braking is calculated, and a threshold for starting to calculate the cumulative motor torque is set. After the chassis braking deceleration reaches a steady state, the motor compensating braking deceleration is updated based on the difference between the vehicle's actual deceleration and the target deceleration; Calculating the feedforward motor torque of the vehicle motor compensatory braking based on the deceleration of the motor compensatory braking, the road sliding resistance and the actual road slope information; Calculate the difference between the actual vehicle deceleration after motor compensation and the target vehicle braking deceleration. When the difference is less than the set threshold, calculate the cumulative motor torque. The feedforward motor torque and the accumulated motor torque are accumulated to update the motor output torque, and the vehicle is braked according to the current motor output torque.

2. The AEB braking control method of claim 1 with closed-loop deceleration control of motor torque, characterized in that: include: A perception information acquisition module is used to acquire and output obstacle position information, obstacle speed information, and obstacle acceleration information on the driving path; Driving parameter acquisition module, used to obtain and output the actual speed and acceleration information of the vehicle; The target deceleration compensation calculation module calculates the target compensation deceleration required for motor braking based on the sensing information and driving parameters; The motor brake feedforward torque calculation module calculates the motor feedforward compensation torque based on the target deceleration required for motor braking; The motor brake closed-loop torque calculation module calculates the motor brake closed-loop torque required to eliminate the error between the vehicle's target deceleration and actual deceleration; The vehicle brake control execution module is used to execute the motor brake torque control command to control the vehicle to stop.

3. The AEB braking control method of claim 2 with closed-loop deceleration control of motor torque, characterized in that: The calculating the braking distance for the vehicle to stop safely based on the position information of the obstacle in the driving path and the expected braking position of the vehicle includes: The relative distance between the vehicle and the obstacle is calculated based on the obstacle position information on the driving path output by the perception information acquisition module, and the braking distance for the vehicle to stop safely is obtained by subtracting the vehicle's expected braking position from the current relative distance.

4. The AEB braking control method of claim 2 or 3 with closed-loop deceleration control of motor torque, characterized in that: Calculate the vehicle's target deceleration based on the vehicle's current actual speed, obstacle speed, and braking distance, including: The target deceleration calculation formula is input based on the vehicle's current actual speed and acceleration output by the driving parameter acquisition module, the obstacle speed output by the perception information acquisition module, and the braking distance value. The target deceleration calculation formula for the vehicle braking is: a goal is the target deceleration of the vehicle, x brk is the vehicle's braking distance, v real is the relative speed between the vehicle and the obstacle, and the calculation formula is v real =v ego -v obj , where v ego is the vehicle speed, v obj is the obstacle speed.

5. The AEB braking control method of claim 1 or 2 with closed-loop deceleration control of motor torque, characterized in that: The motor compensation braking deceleration, road sliding resistance and actual road slope information are input into the motor torque calculation formula FF=mΔar-(Av 2 +Bv+C)r-mgsinθ*r, Where mΔar is the torque required for the motor to implement the target deceleration, m is the vehicle weight, r is the tire dynamic radius of the vehicle, Δa is the deceleration required for motor braking, Av 2 +Bv+C is the road sliding resistance, A, B, and C are the fitted vehicle resistance coefficients respectively. If the current actual vehicle speed is 0, C is the static friction resistance value. If the current actual vehicle speed is greater than 0, C is the dynamic friction resistance value. v is the current actual vehicle speed, mgsinθ is the slope resistance compensation, g is the acceleration of gravity, and θ is the actual road slope.

6. The AEB braking control method of claim 1 or 2 with closed-loop deceleration control of motor torque, characterized in that: The difference between the actual deceleration of the vehicle and the target deceleration of the vehicle braking is input into the PID controller to calculate the motor cumulative torque. The motor cumulative torque is accumulated with the motor feedforward torque to update the motor output torque and control the vehicle to brake.

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