Vehicle control method and system for electric vehicle to pass through traffic light

Abstract

The invention relates to the technical field of electric vehicle control, and provides a whole vehicle control method and system for an electric vehicle to pass through traffic lights, and the method comprises the steps: obtaining an image of a road surface in front of the vehicle, and recognizing a road surface state; vehicle torque is obtained, and a friction coefficient is calculated; based on the pavement state and the friction coefficient, determining a pavement safety vehicle speed; acquiring radar information in front of a vehicle, judging whether a vehicle is in front, and if yes, determining a safe vehicle following speed; obtaining the distance between the vehicle and the stop line, the green light remaining time, the vehicle available maximum speed and the speed limit identification speed, judging whether the vehicle can pass through the traffic light or not by combining the road surface safe speed and the safe following speed, and if yes, calculating the minimum passing speed and sending out a prompt. And the user can more securely pass through the traffic light intersection.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicle control, and in particular relates to a whole vehicle control method and system for an electric vehicle passing through a traffic light. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Many drivers tend to worry or be confused about whether they have enough time left when passing through traffic lights, especially novice drivers. When they are hesitant, they may run a yellow light or a red light; or they may fail to brake in time to stop at the center of the road or the zebra crossing, or they may brake suddenly to stop, which may even cause the following vehicle to fail to brake in time and rear-end the vehicle, resulting in serious traffic accidents; especially in rainy and snowy weather, drivers will have less accurate grasp of the timing of braking, resulting in frequent traffic jams and traffic accidents. Summary of the invention

[0004] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a whole vehicle control method and system for an electric vehicle passing through a traffic light. According to the maximum available speed of the vehicle, the speed limit of the road, the safe following speed when there is a vehicle ahead, and the safe speed of the road in rainy and snowy weather, it is estimated whether the vehicle can safely pass the green light without exceeding the speed limit, and the user is informed through a large screen display or voice prompt, so that the user can drive through the traffic light intersection with more peace of mind.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A first aspect of the present invention provides a whole vehicle control method for an electric vehicle passing through a traffic light, comprising:

[0007] Obtain the road image in front of the vehicle and identify the road condition; obtain the vehicle torque and calculate the friction coefficient; determine the safe road speed based on the road condition and friction coefficient;

[0008] Obtain the vehicle's front radar information to determine whether there is a vehicle ahead. If there is a vehicle ahead, determine the safe following speed;

[0009] Obtain the distance between the vehicle and the stop line, the remaining time on the green light, the vehicle's maximum available speed and the speed indicated by the speed limit, and combine the safe road speed and the safe following speed to determine whether the vehicle can pass the traffic light. If the vehicle can pass the traffic light, calculate the minimum passing speed and issue a reminder.

[0010] Furthermore, the step of determining whether the vehicle can pass through the traffic light includes:

[0011] Determine whether the distance Li between the vehicle and the stop line and the remaining time T of the green light satisfy: V(Tt)≥Li, where V is the maximum available speed V of the vehicle.M , Speed ​​limit sign speed V 一 , the minimum value among the road safety speed Vs and the safety following speed Va, and t is the reserved time;

[0012] If the conditions are met, the vehicle can pass the traffic light, and the minimum passing speed is Vmi n =Li / (Tt);

[0013] If not met, the vehicle cannot pass the traffic light.

[0014] Furthermore, the road safety speed is:

[0015]

[0016] Among them, V M is the maximum available speed of the vehicle; k is determined according to the road conditions; ξ1 and ξ2 are adjustment parameters; a is the threshold; μ is the friction coefficient.

[0017] Furthermore, the friction coefficient is: μ=T / (r·m·g), wherein T is the torque, r is the wheel radius, m is the vehicle mass, and g is the acceleration due to gravity.

[0018] Furthermore, the method for determining the safe following speed is:

[0019] If the vehicle speed V 本 The speed V of the vehicle ahead 前 If the speed of the vehicle is equal to or lower than the speed of the vehicle ahead, and the distance is greater than the set value, then the safe following speed Va=V 前 ;

[0020] If the vehicle speed V 本 Higher than the speed of the vehicle ahead V 前 , and the distance is less than the set value, then the safe following speed Va=q×V 前 , where the q value is obtained experimentally;

[0021] If the vehicle speed V 本 Lower than the speed of the vehicle ahead V 前 , and the distance is less than the set value, then the safe following speed Va=p×V 本 , where the p value is obtained experimentally.

[0022] Furthermore, it also includes: when the vehicle cannot pass the traffic light and the driver gives a deceleration instruction, the vehicle is decelerated by an energy recovery method, and if the energy recovery torque is insufficient, hydraulic braking is compensated by ESP.

[0023] Furthermore, the deceleration of the vehicle when decelerating by the energy recovery method is a=Li / T, wherein Li is the distance between the vehicle and the stop line, and T is the remaining time of the green light.

[0024] A second aspect of the present invention provides a whole vehicle control system for an electric vehicle passing through a traffic light, comprising:

[0025] A road safety speed determination module is configured to: obtain an image of the road surface in front of the vehicle and identify the road surface state; obtain the vehicle torque and calculate the friction coefficient; and determine the road safety speed based on the road surface state and the friction coefficient;

[0026] A safe following vehicle speed module is configured to: obtain the vehicle front radar information, determine whether there is a vehicle ahead, and if there is a vehicle ahead, determine the safe following vehicle speed;

[0027] The judgment module is configured to obtain the distance between the vehicle and the stop line, the remaining time on the green light, the maximum available speed of the vehicle and the speed indicated by the speed limit, and judge whether the vehicle can pass the traffic light in combination with the safe speed on the road and the safe following speed. If the vehicle can pass the traffic light, the minimum passing speed is calculated and a reminder is issued.

[0028] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-mentioned method for controlling an electric vehicle passing through a traffic light.

[0029] A fourth aspect of the present invention provides a computer device, comprising a computer-readable storage medium, a processor, and a computer program stored on the computer-readable storage medium and executable on the processor, wherein when the processor executes the program, the steps in the vehicle control method for an electric vehicle passing through a traffic light as described above are implemented.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention estimates whether the vehicle can safely pass the green light without exceeding the speed limit based on the vehicle's maximum available speed, the road speed limit, the safe following speed when there is a vehicle ahead, and the safe speed on the road in rainy and snowy weather, and informs the user through a large-screen display or voice prompts, allowing the user to drive through the traffic light intersection with greater peace of mind.

[0032] The present invention uses energy recovery to actively limit the vehicle speed when it is determined that the vehicle cannot pass the green light, thereby ensuring the safety of the user. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 is a traffic light intersection operating condition diagram of the first embodiment of the present invention;

[0035] Figure 2 This is a block diagram of an electric vehicle system according to Embodiment 1 of the present invention;

[0036] Figure 3 It is a structural diagram of a computer device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0037] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0038] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0039] Embodiment 1

[0040] This embodiment provides a whole vehicle control method for an electric vehicle passing through a traffic light.

[0041] The present embodiment provides a whole vehicle control method for an electric vehicle passing through a traffic light. The vehicle identifies the remaining time at the traffic light and the distance between the vehicle and the traffic light, estimates whether the vehicle can safely pass the green light without exceeding the speed limit based on the vehicle's maximum available speed, the road speed limit, the safe following speed when there is a vehicle ahead, and the safe speed on the road in rainy and snowy weather, informs the user through a large-screen display or voice prompt, and uses energy recovery to actively limit the speed when it is determined that the vehicle cannot pass the green light, allowing the user to drive through the traffic light intersection with greater peace of mind.

[0042] The present embodiment provides a vehicle control method for an electric vehicle passing through a traffic light, which is applicable to electric vehicles, such as Figure 2 As shown, the electric vehicle includes an image acquisition unit, a vehicle control unit (VCU), a battery management system (BMS), a high-voltage battery, a motor control module (MCU), a motor, a vehicle stability program (ESP), an inverter (DC-DC), a traffic sign recognition system (TSR), an instrument control unit (ICU), a large screen control unit (IHU), and the vehicle's accelerator pedal, shift mechanism, brake pedal, etc.

[0043] Among them, the battery management system (BMS) is responsible for responding to high-voltage connections, calculating charging and discharging power, and sending it to the VCU.

[0044] The image acquisition unit uses a CCD (Charge Coupled Device) to collect images of the road surface in front of the vehicle in real time and send them to the VCU.

[0045] Among them, the motor control module (MCU) collects the motor status in real time and responds to the torque command of the VCU, and feeds back information such as actual torque and speed to the VCU.

[0046] Among them, the vehicle stability program (ESP) collects the vehicle speed and sends it to the VCU.

[0047] Among them, the inverter (DC-DC) collects the output voltage and current and sends them to the VCU.

[0048] Among them, the traffic sign recognition system (TSR) is responsible for identifying information such as traffic lights and speed limits and feeding it back to the VCU.

[0049] Among them, the large screen control unit (IHU) collects the vehicle's front radar information, calculates the distance from the vehicle to the intersection based on GPS positioning, and feeds it back to the VCU.

[0050] Among them, the vehicle control system (VCU) interacts with the above controllers through CAN communication, summarizes the information and calculates whether the vehicle can pass the traffic light intersection within the remaining time of the traffic light under various working conditions.

[0051] Among them, the large-screen control unit (IHU) has display and voice reminder functions, which informs the driver based on the information fed back by the VCU.

[0052] Among them, the instrument control unit (ICU) receives information sent by the VCU to determine whether the intersection can be passed and other information for display.

[0053] This embodiment provides a whole vehicle control method for an electric vehicle passing through a traffic light. When the vehicle passes through a traffic light intersection, a logical judgment is performed starting from the distance L between the vehicle and the stop line, including the following steps:

[0054] Step 1: The vehicle control system (VCU) classifies the road surface image in front of the vehicle into three road conditions: dry, slippery, and extremely slippery.

[0055] Specifically, the classification steps include: extracting the road area in the image through image segmentation, and removing vehicle interference through an adaptive threshold method; extracting the image texture attribute value and grayscale average value in the road area, and then classifying through a Bayesian classifier, etc.

[0056] Step 2: Based on the torque T, calculate the friction coefficient: μ = T / (r·m·g), where r is the wheel radius, m is the vehicle mass, and g is the acceleration of gravity. The μ on a dry asphalt road is approximately 0.6 to 0.8, and the μ on an icy road is as low as 0.1 to 0.2.

[0057] Step 3: Determine the safe road speed based on the road surface condition and friction coefficient μ:

[0058]

[0059] Among them, V M is the maximum available vehicle speed; k is determined according to the road surface condition. In this embodiment, when the road surface condition is dry, it is 0.7; when the road surface condition is wet and slippery, it is 0.4; when the road surface condition is extremely slippery, it is 0.1; ξ1 and ξ2 are adjustment parameters; a is a threshold value, which is 0.3; according to the value, when the difference between k and μ is small, it means that the image recognition result and the friction coefficient calculation result are close, and there is an error in the image recognition result or the friction coefficient calculation result not caused by other reasons. At this time, the product of the two is used for adjustment, and the vehicle speed adjustment effect is obvious; when the difference between k and μ is large, there are other factors affecting the image recognition result or the friction coefficient calculation result, resulting in inaccurate calculation. At this time, the median of the two is taken for adjustment, which can avoid excessive speed adjustment caused by error and affect driving.

[0060] Among them, the maximum available vehicle speed is calculated by the VCU based on the available power of the motor and battery, and takes into account the speed limit when the vehicle fails or the power is limited.

[0061] Step 4: VCU determines whether there is a vehicle ahead based on the vehicle's front radar information; if there is no vehicle ahead, the safe following speed Va = speed limit speed V max , then go directly to step 5; otherwise, obtain the vehicle speed V 本 (like Figure 1 V1, V2, V3 and V4), the front vehicle speed V 前 and the distance A between the vehicle and the vehicle ahead (e.g. Figure 1 A1 and A2 in the figure are used to adjust the speed of the vehicle to obtain the safe following speed:

[0062] (1) If the speed of the vehicle is equal to that of the vehicle in front or is lower than that of the vehicle in front, and the distance is greater than the set value of 3m, the driver is reminded to keep the speed of the vehicle unchanged or accelerate to the same speed as the vehicle in front. At this time, the safe following speed Va = V 前 ;

[0063] (2) If the vehicle speed is higher than that of the preceding vehicle and the distance is less than the set value of 3m, the driver is reminded to take deceleration measures, reduce the speed, and maintain a safe distance. At this time, the safe following speed is Va = q × V 前 , where the q value is obtained based on experiments and its value is less than 1.

[0064] (3) If the speed of the vehicle is lower than that of the vehicle ahead and the distance is less than the set value of 3m, the driver is reminded to slow down and maintain a safe distance. At this time, the safe following speed is Va = p × V 本 , where the p value is obtained experimentally and its value is less than 1.

[0065] Step 5: Determine whether the distance Li between the vehicle and the stop line and the remaining time of the green light satisfy the following formula:

[0066] V(Tt)≥Li

[0067] Among them, V is the maximum available speed of the vehicle V M , Speed ​​limit sign speed V max , the minimum value of the road safety speed Vs, and the safe following speed Va. T is the remaining time of the green light, t is the reserved time set by the user (such as 1s), and Li is the current distance between the vehicle and the stop line (such as Figure 1 L1, L2, L3, L4).

[0068] If the above formula is satisfied, the vehicle can pass the traffic light normally, and the minimum passing speed V is calculated. min =Li / (Tt), the driver is prompted by voice or display through the large screen control unit;

[0069] If the above formula is not satisfied, the vehicle is not fast enough to pass directly at the current green light and needs to slow down and stop and wait for the next green light. The large-screen control unit will prompt the driver with voice or display: If the driver does not brake to slow down, the VCU can decelerate the vehicle to 10km / h (calibrable) through energy recovery method according to the deceleration a=Li / T, so that the driver can stop at any time. If the energy recovery torque is insufficient, ESP can be used to compensate for hydraulic braking to meet the deceleration a requirement. At the same time, the VCU determines whether to turn on the brake lights or double flashes to warn the vehicle behind according to the deceleration; if the driver directly brakes to slow down, the driver's request will be responded to directly.

[0070] Embodiment 2

[0071] This embodiment provides a whole vehicle control system for an electric vehicle passing through a traffic light, which specifically includes:

[0072] A road safety speed determination module is configured to: obtain an image of the road surface in front of the vehicle and identify the road surface state; obtain the vehicle torque and calculate the friction coefficient; and determine the road safety speed based on the road surface state and the friction coefficient;

[0073] A safe following vehicle speed module is configured to: obtain the vehicle front radar information, determine whether there is a vehicle ahead, and if there is a vehicle ahead, determine the safe following vehicle speed;

[0074] The judgment module is configured to obtain the distance between the vehicle and the stop line, the remaining time on the green light, the maximum available speed of the vehicle and the speed indicated by the speed limit, and judge whether the vehicle can pass the traffic light in combination with the safe speed on the road and the safe following speed. If the vehicle can pass the traffic light, the minimum passing speed is calculated and a reminder is issued.

[0075] It should be noted here that each module in this embodiment corresponds to each step in Example 1 one by one, and the specific implementation process is the same, which will not be repeated here.

[0076] Embodiment 3

[0077] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the whole vehicle control method for an electric vehicle passing through a traffic light as described in the first embodiment above are implemented.

[0078] Embodiment 4

[0079] This embodiment provides a computer device, such as Figure 3 As shown, it includes a display device, an input device, a computer-readable storage medium (volatile memory and non-volatile storage medium), a processor, a communication interface (i.e., a network interface), and a computer program stored on the computer-readable storage medium and executable on the processor, wherein the processor, the communication interface, and the computer-readable storage medium can be connected via a bus or other means. The communication interface is used to receive and send data, and when the processor executes the program, the steps in the vehicle control method for an electric vehicle passing through a traffic light as described in the first embodiment above are implemented.

[0080] Among them, any reference to memory, storage, database or other media provided by the present application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual-speed data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0081] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0082] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0083] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A whole vehicle control method for an electric vehicle passing through a traffic light, characterized in that: include: Acquire the road surface image in front of the vehicle and identify the road surface condition; Obtain vehicle torque and calculate friction coefficient; Determine the safe speed on the road based on the road surface condition and friction coefficient; Obtain the vehicle's front radar information to determine whether there is a vehicle ahead. If there is a vehicle ahead, determine the safe following speed; Obtain the distance between the vehicle and the stop line, the remaining time on the green light, the vehicle's maximum available speed and the speed indicated by the speed limit, and combine the safe road speed and the safe following speed to determine whether the vehicle can pass the traffic light. If the vehicle can pass the traffic light, calculate the minimum passing speed and issue a reminder.

2. A whole vehicle control method for an electric vehicle passing through a traffic light as claimed in claim 1, characterized in that: The step of determining whether a vehicle can pass a traffic light comprises: Determine whether the distance Li between the vehicle and the stop line and the remaining time T of the green light satisfy: V(Tt)≥Li, where V is the maximum available speed V of the vehicle. M , Speed ​​limit sign speed V max , the minimum value among the road safety speed Vs and the safety following speed Va, and t is the reserved time; If it is satisfied, the vehicle can pass the traffic light, and the minimum passing speed is V min =Li / (Tt); If not met, the vehicle cannot pass the traffic light.

3. The whole vehicle control method for an electric vehicle passing through a traffic light as claimed in claim 1, characterized in that: The road safety speed is: Among them, V M is the maximum available speed of the vehicle; k is determined according to the road conditions; ξ1 and ξ2 are adjustment parameters; a is the threshold; μ is the friction coefficient.

4. The whole vehicle control method for an electric vehicle passing through a traffic light as claimed in claim 1, characterized in that: The friction coefficient is: μ=T / (r·m·g), where T is the torque, r is the wheel radius, m is the vehicle mass, and g is the gravitational acceleration.

5. The whole vehicle control method for an electric vehicle passing through a traffic light as claimed in claim 1, characterized in that: The method for determining the safe following speed is as follows: If the vehicle speed V 本 The speed V of the vehicle ahead 前 If the speed of the vehicle is equal to or lower than the speed of the vehicle ahead, and the distance is greater than the set value, then the safe following speed Va=V 前 ; If the vehicle speed V 本 Higher than the speed of the vehicle ahead V 前 , and the distance is less than the set value, then the safe following speed Va=q×V 前 , where the q value is obtained experimentally; If the vehicle speed V 本 Lower than the speed of the vehicle ahead V 前 , and the distance is less than the set value, then the safe following speed Va=p×V 本 , where the p value is obtained experimentally.

6. The whole vehicle control method for an electric vehicle passing through a traffic light as claimed in claim 1, characterized in that: Also includes: When the vehicle cannot pass the traffic light and the driver gives a deceleration instruction, the vehicle is decelerated by energy recovery. If the energy recovery torque is insufficient, ESP is used to compensate for hydraulic braking.

7. A whole vehicle control method for an electric vehicle passing through a traffic light as claimed in claim 6, characterized in that: The deceleration of the vehicle when decelerating by the energy recovery method is a=Li / T, wherein Li is the distance between the vehicle and the stop line, and T is the remaining time of the green light.

8. A vehicle control system for an electric vehicle passing a traffic light, characterized in that: include: A road safety speed determination module is configured to: obtain an image of the road surface in front of the vehicle and identify the road surface state; Obtain vehicle torque and calculate friction coefficient; Determine the safe speed on the road based on the road surface condition and friction coefficient; A safe following vehicle speed module is configured to: obtain the vehicle front radar information, determine whether there is a vehicle ahead, and if there is a vehicle ahead, determine the safe following vehicle speed; The judgment module is configured to obtain the distance between the vehicle and the stop line, the remaining time on the green light, the maximum available speed of the vehicle and the speed indicated by the speed limit, and judge whether the vehicle can pass the traffic light in combination with the safe speed on the road and the safe following speed. If the vehicle can pass the traffic light, the minimum passing speed is calculated and a reminder is issued.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in a whole vehicle control method for an electric vehicle passing through a traffic light as described in any one of claims 1 to 7 are implemented.

10. A computer device comprising a computer-readable storage medium, a processor, and a computer program stored in the computer-readable storage medium and executable on the processor, characterized in that: When the processor executes the program, the steps in the whole vehicle control method for an electric vehicle passing through a traffic light as described in any one of claims 1-7 are implemented.

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