Vehicle speed control method and device, vehicle control unit and vehicle
By using the brake pedal switch signal and opening degree to control the vehicle's target speed, the problem of drivers frequently switching pedals on crowded roads is solved, and the driving experience and safety are improved.
Patent Information
- Application Number
- CN202411742046.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-03-18
AI Technical Summary
On crowded roads, drivers need to switch brake pedals and accelerator pedals frequently, resulting in poor driving experience.
By obtaining the brake pedal switch signal and opening, the vehicle controller can control the vehicle to drive at the target vehicle speed. The target vehicle speed is negatively correlated with the brake pedal opening and is not greater than the set vehicle speed threshold, so as to control the vehicle's low-speed driving or stationary speed by relying solely on the brake pedal.
无需频繁切换制动踏板和加速踏板,提升了驾驶员在拥堵场景下的驾驶体验,确保了驾驶安全性。
Smart Images
Figure CN119636726A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of vehicle control technology, and in particular to a vehicle speed control method, device, vehicle controller and vehicle. Background Art
[0002] Currently, when a vehicle is traveling on a crowded road, the driver needs to step on the brake pedal to brake and step on the accelerator pedal to accelerate. This means that the driver needs to frequently switch between the brake pedal and the accelerator pedal, resulting in a poor driver experience. Summary of the invention
[0003] The embodiments of the present application provide a vehicle speed control method, device, vehicle controller and vehicle, which can control the vehicle to travel at a low speed or standstill only by relying on the brake pedal, without the driver having to frequently switch between the brake pedal and the accelerator pedal, thereby improving the driver's driving experience in congested scenarios.
[0004] In a first aspect, an embodiment of the present application provides a method for controlling vehicle speed, the method comprising: Obtain brake pedal switch signal and brake pedal opening; In response to the brake pedal switch signal indicating that the brake pedal is not enabled, the vehicle is controlled to travel based on a target vehicle speed according to the brake pedal opening, wherein the target vehicle speed is negatively correlated with the brake pedal opening, and the target vehicle speed is not greater than a set vehicle speed threshold.
[0005] In the embodiment of the present application, the vehicle controller can obtain the brake pedal switch signal. If the brake pedal switch signal indicates that the brake pedal is not enabled, it means that the brake pedal opening formed by the brake pedal being stepped on does not reach the brake pedal opening threshold, and the vehicle controller knows that the vehicle is not in a braking state at this time. On this basis, the vehicle controller can also obtain the brake pedal opening, which may be any value between 0 and the brake pedal opening threshold, and then use the brake pedal opening to control the vehicle to travel at a target speed lower than the set speed threshold, and the larger the brake pedal opening, the smaller the target speed, so that the vehicle can be controlled to be stationary, that is, the brake pedal can be used to stop; on the contrary, the smaller the brake pedal opening, the larger the target speed, so that the vehicle can be controlled to travel at a low speed, so that the driver can rely only on the brake pedal to control the vehicle in a road congestion scenario, without frequently switching between the brake pedal and the accelerator pedal, thereby improving the driver's driving experience.
[0006] Optionally, the set vehicle speed threshold is the maximum vehicle speed corresponding to the creep function.
[0007] In the embodiment of the present application, since the maximum vehicle speed corresponding to the creeping function is usually small, the maximum vehicle speed corresponding to the creeping function is used as the upper limit of the target vehicle speed in a congested scenario, which can better ensure driving safety in a congested scenario.
[0008] Optionally, controlling the vehicle to travel based on a target vehicle speed according to the brake pedal opening includes: determining the target vehicle speed of the creep function according to the brake pedal opening; The creep function is activated to control the vehicle to travel based on the target vehicle speed.
[0009] In an embodiment of the present application, a correspondence can be established between different brake pedal openings and the vehicle speed from 0 to the maximum under the creep function, and then the actual vehicle speed under the creep function can be determined based on the actual brake pedal opening. Then, by activating the creep function, it is possible to control the vehicle speed by relying solely on the brake pedal.
[0010] Optionally, controlling the vehicle to travel based on the target vehicle speed includes: Acquiring a first actual vehicle speed of the vehicle; determining a first basic requested torque according to the first actual vehicle speed and the brake pedal opening, wherein the first basic requested torque is positively correlated with the first actual vehicle speed and negatively correlated with the brake pedal opening; determining a first target requested torque according to the first basic requested torque, the first actual vehicle speed, and the target vehicle speed; sending the first target requested torque to a motor controller; Acquiring a second actual vehicle speed of the vehicle; determining a second basic requested torque according to the second actual vehicle speed and the brake pedal opening, wherein the second basic requested torque is positively correlated with the second actual vehicle speed and negatively correlated with the brake pedal opening; determining a second target requested torque according to the second basic requested torque, the second actual vehicle speed, and the target vehicle speed; The second target request torque is sent to a motor controller until the vehicle travels based on the target vehicle speed.
[0011] In the embodiment of the present application, the greater the actual vehicle speed, the greater the required driving torque can be considered; the greater the vehicle brake pedal opening, the smaller the target vehicle speed to be achieved can be considered, and further, the required driving torque can be considered to be smaller. Therefore, the basic requested torque can be determined in combination with the actual vehicle speed and the brake pedal opening, for example, the first basic requested torque. If the actual vehicle speed is less than the target vehicle speed, the first basic requested torque can be considered to be less than the target requested torque required to reach the target vehicle speed; if the actual vehicle speed is greater than the target vehicle speed, the first basic requested torque can be considered to be greater than the target requested torque required to reach the target vehicle speed. On this basis, the first target requested torque is determined according to the first basic requested torque, the actual vehicle speed and the target vehicle speed, so that the first actual speed of the vehicle gradually approaches the target speed; and then the above process is repeated again until the actual vehicle speed reaches the target speed. In this method, a certain size of basic request torque is used as the basis, and the target request torque is determined in combination with the actual vehicle speed and the target vehicle speed. The above process is repeated continuously, and the target request torque is gradually increased or decreased, which not only reduces the inertia caused by the rapid increase or decrease of the target request torque, but also ensures that the time required to go from the actual vehicle speed to the target vehicle speed is short.
[0012] Optionally, determining a first basic requested torque according to the first actual vehicle speed and the brake pedal opening includes: determining a corresponding third basic requested torque according to the first actual vehicle speed, wherein the third basic requested torque is positively correlated with the first actual vehicle speed; determining a torque coefficient according to the brake pedal opening, wherein the torque coefficient is negatively correlated with the brake pedal opening; The first base torque is determined according to the third base request torque and the torque coefficient.
[0013] In the embodiment of the present application, a correspondence between the actual vehicle speed and the basic requested torque can be established in advance, and then the third basic requested torque corresponding to the first actual vehicle speed can be determined based on the above correspondence. Similarly, a correspondence between the brake pedal opening and the torque coefficient can be established in advance, and then the torque coefficient corresponding to the brake pedal opening can be determined based on the above correspondence. On this basis, the first basic torque can be conveniently determined based on the third basic requested torque and the torque coefficient.
[0014] Optionally, determining a first target requested torque according to the first basic requested torque, the first actual vehicle speed, and the target vehicle speed includes: calculating a vehicle speed difference between the target vehicle speed and the first actual vehicle speed; Inputting the vehicle speed difference into a PID controller to obtain a requested torque increment; The first target requested torque is determined according to the first base torque and the requested torque increase.
[0015] In the embodiment of the present application, the speed difference between the target vehicle speed and the first actual differential speed is used as the input of the PID controller, and then the PID controller is used to output the requested torque increment. Then, combined with the first basic torque that has been obtained in advance, the current first target requested torque can be determined. Since the PID controller is only responsible for outputting the requested torque increment, rather than the first target requested torque, the PID can output the result faster, thereby improving the response speed to a certain extent.
[0016] Optionally, obtain the brake pedal opening, including: Receive brake master cylinder pressure signal from electronic stability control system; Determine the brake pedal opening according to the brake master cylinder pressure signal; or The brake pedal opening is received from an electronic brake system.
[0017] In an embodiment of the present application, since the electronic stability control system monitors the brake master cylinder pressure, the vehicle controller can receive the brake master cylinder pressure from the electronic stability control system to reversely infer the brake pedal opening; or, since the brake pedal opening can be monitored in the electronic braking system, the vehicle controller can obtain the brake pedal opening from the electronic braking system more conveniently.
[0018] In a second aspect, an embodiment of the present application provides a vehicle speed control device, the device comprising: An acquisition unit, used for acquiring a brake pedal switch signal and a brake pedal opening; A control unit is used to control the vehicle to travel based on a target vehicle speed in response to the brake pedal switch signal indicating that the brake pedal is not enabled according to the brake pedal opening, wherein the target vehicle speed is negatively correlated with the brake pedal opening, and the target vehicle speed is not greater than a set vehicle speed threshold.
[0019] Optionally, the set vehicle speed threshold is the maximum vehicle speed corresponding to the creep function.
[0020] Optionally, the control unit includes: a vehicle speed determination unit, configured to determine the target vehicle speed of the creep function according to the brake pedal opening; A driving control unit is used to activate the creep function and control the vehicle to travel based on the target vehicle speed.
[0021] Optionally, the driving control unit includes: A vehicle speed acquisition subunit, used to acquire a first actual vehicle speed of the vehicle; a basic torque determination subunit, configured to determine a first basic requested torque according to the first actual vehicle speed and the brake pedal opening, wherein the first basic requested torque is positively correlated with the first actual vehicle speed and negatively correlated with the brake pedal opening; a target torque determination subunit, configured to determine a first target requested torque according to the first basic requested torque, the first actual vehicle speed and the target vehicle speed; A request torque sending subunit, used for sending the first target request torque to the motor controller; The vehicle speed acquisition subunit is further used to acquire a second actual vehicle speed of the vehicle; The basic torque determination subunit is further used to determine a second basic request torque according to the second actual vehicle speed and the brake pedal opening, wherein the second basic request torque is positively correlated with the second actual vehicle speed and negatively correlated with the brake pedal opening; The target torque determination subunit is configured to determine a second target requested torque according to the second basic torque, the second actual vehicle speed and the target vehicle speed; The requested torque sending subunit is further configured to send the second target requested torque to the motor controller until the vehicle travels based on the target vehicle speed.
[0022] Optionally, the basic torque determination subunit is specifically used for: determining a corresponding third basic requested torque according to the first actual vehicle speed, wherein the third basic requested torque is positively correlated with the first actual vehicle speed; determining a torque coefficient according to the brake pedal opening, wherein the torque coefficient is negatively correlated with the brake pedal opening; The first base torque is determined according to the third base request torque and the torque coefficient.
[0023] Optionally, the target torque determination subunit is specifically used for: calculating a vehicle speed difference between the target vehicle speed and the first actual vehicle speed; Inputting the vehicle speed difference into a PID controller to obtain a requested torque increment; The first target requested torque is determined according to the first base torque and the requested torque increase.
[0024] Optionally, the acquiring unit is specifically used for: Receive brake master cylinder pressure signal from electronic stability control system; Determine the brake pedal opening according to the brake master cylinder pressure signal; or The brake pedal opening is received from an electronic brake system.
[0025] In a third aspect, an embodiment of the present application provides a vehicle controller, which includes a memory for storing computer program instructions and a processor for executing program instructions, wherein when the computer program instructions are executed by the processor, the vehicle controller is triggered to execute the steps of the method described in any embodiment of the first aspect.
[0026] In a fourth aspect, an embodiment of the present application provides a vehicle, comprising the vehicle controller in the embodiment of the third aspect.
[0027] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store computer instructions, and when the computer is running, the computer causes the computer to execute the steps of the method described in any embodiment of the first aspect.
[0028] It should be understood that the second to fifth aspects of the embodiments of the present application are consistent with the technical solutions of the first aspect of the embodiments of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0030] Figure 1 A schematic flow chart of a vehicle speed control method provided in an embodiment of the present application; Figure 2 A schematic flow chart of a vehicle speed control method based on creep function provided in an embodiment of the present application; Figure 3 A schematic diagram of a flow chart of a method for controlling a vehicle to travel based on a target vehicle speed provided in an embodiment of the present application; Figure 4 A schematic diagram of a flow chart of a method for determining a first basic requested torque provided in an embodiment of the present application; Figure 5 A schematic diagram of a flow chart of a method for determining a first basic requested torque provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of a vehicle speed control device provided in an embodiment of the present application; Figure 7 A schematic diagram of the structure of a vehicle controller provided in an embodiment of the present application; Figure 8 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION
[0031] In order to better understand the technical solution of this specification, the embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0032] It should be clear that the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.
[0033] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit this specification. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.
[0034] Currently, when a vehicle is traveling on a crowded road, the driver needs to step on the brake pedal to brake and step on the accelerator pedal to accelerate. This means that the driver needs to frequently switch between the brake pedal and the accelerator pedal, resulting in a poor driver experience.
[0035] In view of this, an embodiment of the present application provides a method for controlling vehicle speed. In this method, it is first determined whether the brake pedal is enabled. If it is not enabled, it indicates that the brake pedal opening has not reached the brake pedal opening threshold. At this time, the vehicle is not in a braking state. Therefore, the brake pedal opening can be used to control the vehicle to travel at a target speed. The target speed here can be considered to be a low speed or a stationary speed. In this way, the driver can rely solely on the brake pedal to control the vehicle's travel in a road congestion scenario, without the need to frequently switch between the brake pedal and the accelerator pedal, thereby improving the driver's driving experience.
[0036] The technical solution protected by the embodiments of the present application is described in detail below with reference to the accompanying drawings.
[0037] See also Figure 1 , is a flow chart of a vehicle speed control method provided in an embodiment of the present application, the method is applied to a vehicle control unit (VCU), and the flow of the method is described as follows: Step 10: Obtain the brake pedal switch signal and the brake pedal opening.
[0038] In the embodiment of the present application, on the one hand, the VCU can obtain the brake pedal switch signal, for example, the brake pedal switch signal can have two states of 0 and 1. When the brake pedal switch signal is 0, it indicates that the brake pedal opening is less than the brake pedal opening threshold, and the brake pedal is not enabled; when the brake pedal switch signal is 1, it indicates that the brake pedal opening is greater than or equal to the brake pedal opening threshold, and the brake pedal is enabled. On the other hand, the VCU can obtain the brake pedal opening. For example, for a vehicle equipped with an electronic stability control system (ESC), the ESC can monitor the brake master cylinder pressure signal in the vehicle, and then the ESC can send the brake master cylinder pressure signal to the VCU. The VCU can determine the brake pedal opening corresponding to the current brake master cylinder pressure signal based on the pre-established correspondence between the brake master cylinder pressure and the brake pedal opening. Alternatively, for a vehicle equipped with an electronic brake system (EBS), the EBS can directly monitor the brake pedal opening, and then the EBS can send the monitored brake pedal opening to the VCU.
[0039] Step 20: In response to the brake pedal switch signal indicating that the brake pedal is not enabled, controlling the vehicle to travel based on a target vehicle speed according to the brake pedal opening.
[0040] In the embodiment of the present application, if the brake pedal switch signal received by the VCU is 0, the VCU can determine that the brake pedal is not enabled, which means that the vehicle is not currently in a braking state. Since the current brake pedal opening may be any value between 0 and the brake pedal opening threshold, the brake pedal opening can be used to control the vehicle to travel at a target speed lower than the set speed threshold. For example, the target speed is negatively correlated with the brake pedal opening. When the brake pedal opening increases from 0 to gradually approach the brake pedal opening threshold, the target speed gradually decreases from the set speed threshold until it reaches 2km / h, 1km / h or 0 km / h. It should be understood that during the gradual increase of the brake pedal opening, the target speed can be linearly decreased, stepped decreased, or nonlinearly decreased; conversely, when the brake pedal opening gradually decreases from the brake pedal opening threshold until it reaches 0, the target speed can be increased from 0km / h, 1km / h or 2km / h until it reaches the set speed threshold. It should be understood that, during the process of gradually decreasing the brake pedal opening, the target vehicle speed may be increased linearly, stepwise, or nonlinearly. The above vehicle speed control method enables the driver to control the vehicle only by the brake pedal in a road congestion scenario, without the need to frequently switch between the brake pedal and the accelerator pedal, thereby improving the driver's driving experience.
[0041] It is worth noting that since the maximum vehicle speed corresponding to the creep function is usually small, for example, usually not exceeding 10km / h, using the maximum vehicle speed corresponding to the creep function as the upper limit of the target vehicle speed in congested scenarios can better ensure driving safety in congested scenarios.
[0042] The following is a detailed description of how the driver uses the brake pedal to control the vehicle's travel.
[0043] See also Figure 2 , is a flow chart of a vehicle speed control method based on creep function provided in an embodiment of the present application. Step 20 can be implemented by executing sub-steps 201 and 202: Step 201: Determine the target vehicle speed of the creep function according to the brake pedal opening.
[0044] Step 202: Activate the creep function to control the vehicle to travel based on the target speed.
[0045] In an embodiment of the present application, the VCU pre-stores the correspondence between different brake pedal openings and different vehicle speeds between 0 and the maximum vehicle speed under the creep function. Then, based on the above correspondence, the target vehicle speed under the creep function corresponding to the current brake pedal opening is determined. Then, by activating the creep function, it is possible to control the vehicle to travel based on the target speed by relying solely on the brake pedal.
[0046] In some embodiments, considering that the VCU needs to make a torque request to the motor control unit (MCU) so that the actual speed of the vehicle can gradually reach the target speed, if the torque requested by the VCU changes greatly in a short period of time, the vehicle will jump forward or backward; if the torque requested by the VCU changes little, the vehicle will take a long time to reach the target speed, resulting in a poor driving experience for the driver.
[0047] In view of this, in the embodiment of the present application, the torque requested by the VCU to the MCU is divided into two links. The first link is to determine the basic requested torque based on the current driving state of the vehicle and the driving behavior of the driver. The second link is to determine the current target torque to be requested based on the basic requested torque, combined with the actual vehicle speed and the target vehicle speed. Then the above process is repeated until the actual vehicle speed approaches the target vehicle speed. This method can ensure that adjacent target requested torques will not differ greatly, and the time to reach the target requested torque corresponding to the target vehicle speed will not be too long, thereby ensuring the driver's driving experience.
[0048] See also Figure 3, is a flow chart of a method for controlling a vehicle to travel based on a target speed provided in an embodiment of the present application. Step 202 can be implemented by executing sub-steps 2021 to 2028: Step 2021: Obtain the first actual vehicle speed.
[0049] Step 2022: Determine a first basic requested torque according to the first actual vehicle speed and the brake pedal opening, wherein the first basic requested torque is positively correlated with the first actual vehicle speed and negatively correlated with the brake pedal opening.
[0050] In the embodiment of the present application, the greater the actual vehicle speed, the greater the required driving torque can be considered; the greater the vehicle brake pedal opening, the smaller the target vehicle speed to be achieved can be considered, and further, the required driving torque can be considered to be smaller. Therefore, the basic requested torque can be determined in combination with the actual vehicle speed and the brake pedal opening, for example, the first basic requested torque. If the actual vehicle speed is less than the target vehicle speed, the first basic requested torque can be considered to be less than the target requested torque required to reach the target vehicle speed; if the actual vehicle speed is greater than the target vehicle speed, the first basic requested torque can be considered to be greater than the target requested torque required to reach the target vehicle speed.
[0051] How to determine the first basic requested torque is described in detail below.
[0052] See also Figure 4 , which is a flow chart of a method for determining a first basic requested torque provided in an embodiment of the present application. Step 2022 can be implemented by executing sub-steps 301 to 303: Step 301 : Determine a corresponding third basic requested torque according to the first actual vehicle speed, where the third basic requested torque is positively correlated with the first actual vehicle speed.
[0053] Step 302: Determine a torque coefficient according to the brake pedal opening, where the torque coefficient is negatively correlated with the brake pedal opening.
[0054] Step 303: Determine a first basic torque according to the third basic request torque and the torque coefficient.
[0055] In the embodiment of the present application, the VCU pre-stores a correspondence between the actual vehicle speed and the basic requested torque. In this correspondence, the basic requested torque can be considered to be greater than or equal to the torque required to overcome the vehicle resistance (rolling resistance, sliding resistance and air resistance) at the corresponding actual vehicle speed. The actual vehicle speed is positively correlated with the basic requested torque. Then, according to the above correspondence, the third basic requested torque corresponding to the first actual vehicle speed is determined. Similarly, the VCU pre-stores a correspondence between the brake pedal opening and the torque coefficient. In this correspondence, the brake pedal opening and the torque coefficient are negatively correlated. Then, according to the above correspondence, the torque coefficient corresponding to the brake pedal opening is determined. On this basis, the first basic torque is conveniently determined according to the third basic requested torque and the torque coefficient.
[0056] Step 2023: Determine a first target requested torque according to the first basic requested torque, the first actual vehicle speed and the target vehicle speed.
[0057] In the embodiment of the present application, when the first actual vehicle speed is less than the target vehicle speed, the determined first target requested torque is greater than the first basic requested torque; conversely, when the first actual vehicle speed is greater than or equal to the target vehicle speed, the determined first target requested torque is less than the first target requested torque.
[0058] How to determine the first target requested torque is described in detail below.
[0059] See also Figure 5 , which is a flow chart of a method for determining a first target requested torque provided in an embodiment of the present application. Step 2023 can be implemented by executing sub-steps 401 to 403: Step 401: Calculate the vehicle speed difference between the target vehicle speed and the first actual vehicle speed.
[0060] Step 402: Input the vehicle speed difference to the PID controller to obtain the requested torque increment.
[0061] Step 403: Determine a first target requested torque according to the first basic torque and the requested torque increment.
[0062] In the embodiment of the present application, the speed difference between the target vehicle speed and the first actual differential speed is used as the input of the PID controller, and then the PID controller is used to output the requested torque increment. It should be understood that if the speed difference is a positive value, the requested torque increment output by the PID controller is also a positive value; conversely, if the speed difference is a negative value, the requested torque increment output by the PID controller is also a negative value.
[0063] On the basis of obtaining the requested torque increment, the current first target requested torque can be determined in combination with the first basic requested torque that has been obtained in advance. Since the PID controller is only responsible for outputting the requested torque increment instead of the first target requested torque, the PID controller can output the result faster, thereby improving the response speed to a certain extent.
[0064] Step 2024: Send a first target requested torque to the motor controller.
[0065] In the embodiment of the present application, the VCU requests a first target torque from the MCU, and the MCU will output based on the first target request torque, thereby reducing the speed difference between the actual speed of the vehicle and the target speed.
[0066] Step 2025: Obtain a second actual vehicle speed.
[0067] Step 2026: Determine a second basic requested torque according to the second actual vehicle speed and the brake pedal opening, wherein the second basic requested torque is positively correlated with the second actual vehicle speed and negatively correlated with the brake pedal opening.
[0068] Step 2027: Determine a second target requested torque according to the second basic requested torque, the second actual vehicle speed and the target vehicle speed.
[0069] Step 2028: Send a second target requested torque to the motor controller until the vehicle travels based on the target vehicle speed.
[0070] In the embodiment of the present application, the VCU sends the requested torque to the MCU multiple times to gradually increase or decrease the requested torque, thereby avoiding the inertia caused by the rapid increase or decrease of the target requested torque.
[0071] The change process of the target requested torque in the present application scheme is described below in conjunction with Table 1.
[0072] Table 1 As shown in Table 1, if the current actual vehicle speed is 2km / h and the target vehicle speed is 10km / h, the target vehicle speed (10km / h) is greater than the actual vehicle speed (2km / h), and the target request torque sent by the VCU for the first time is 35N·m. If the MCU outputs the driving torque based on 35N·m so that the actual vehicle speed reaches 4km / h, and the target vehicle speed (10km / h) is still greater than the actual vehicle speed (4km / h), then the target request torque sent by the VCU for the second time is 60N·m. If the MCU outputs the driving torque based on 60N·m so that the actual vehicle speed reaches 6km / h, and the target vehicle speed (10km / h) is still greater than the actual vehicle speed (6km / h), then the target request torque sent by the VCU for the third time is 93N·m. If the MCU outputs the driving torque based on 93N·m so that the actual speed of the vehicle reaches 8km / h, and the target speed (10km / h) is still greater than the actual speed (8km / h), then the target request torque sent by the VCU for the third time is 134N·m, and the MCU outputs the driving torque based on 134N·m so that the actual speed of the vehicle reaches 10km / h. It can be seen that in order to increase the actual speed from 2km / h to the target speed of 10km / h, compared with the target request torque directly increasing from 0 to 134N·m, the target request torque in this application is gradually increased from 35N·m to 134N·m, which is equivalent to reducing the growth rate of the target request torque, making the growth of the target request torque smoother, avoiding the problem of vehicle movement, and improving the driver's driving experience. At the same time, since the basic request torque is set, the torque increment is relatively small and can converge in a relatively short time, so that the time from the actual speed from 2km / h to the target speed of 10km / h will not be too long.
[0073] Similarly, if the current actual vehicle speed is 10km / h and the target vehicle speed is 2km / h, compared to the target requested torque directly reduced to the requested torque corresponding to 2km / h, in this application, the target requested torque will gradually decrease to the requested torque corresponding to 2km / h, which is equivalent to reducing the reduction speed of the target requested torque, making the reduction process of the target requested torque smoother, avoiding the problem of vehicle movement, and improving the driving experience of the driver. At the same time, since the basic requested torque is set, the torque increment is relatively small and can converge in a relatively short time, so that the time from the actual vehicle speed of 10km / h to the target vehicle speed of 2km / h will not be too long.
[0074] See also Figure 6 Based on the same inventive concept, an embodiment of the present application provides a vehicle speed control device, the device comprising: An acquisition unit 501 is used to acquire a brake pedal switch signal and a brake pedal opening; The control unit 502 is used to control the vehicle to travel based on a target speed according to the brake pedal opening in response to a brake pedal switch signal indicating that the brake pedal is not enabled, wherein the target speed is negatively correlated with the brake pedal opening and the target speed is not greater than a set speed threshold.
[0075] Optionally, the vehicle speed threshold is set to the maximum vehicle speed corresponding to the creep function.
[0076] Optionally, the control unit 502 includes: A vehicle speed determination unit, used to determine a target vehicle speed of a creeping function according to a brake pedal opening; The driving control unit is used to activate the creep function and control the vehicle to travel based on the target speed.
[0077] Optionally, the driving control unit includes: A vehicle speed acquisition subunit, used to acquire a first actual vehicle speed; a basic torque determination subunit, configured to determine a first basic requested torque according to the first actual vehicle speed and the brake pedal opening, wherein the first basic requested torque is positively correlated with the first actual vehicle speed and negatively correlated with the brake pedal opening; a target torque determination subunit, configured to determine a first target requested torque according to a first basic requested torque, a first actual vehicle speed and a target vehicle speed; A request torque sending subunit, used for sending a first target request torque to the motor controller; The vehicle speed acquisition subunit is further used to acquire a second actual vehicle speed; The basic torque determination subunit is further used to determine a second basic request torque according to the second actual vehicle speed and the brake pedal opening, wherein the second basic request torque is positively correlated with the second actual vehicle speed and negatively correlated with the brake pedal opening; a target torque determination subunit, configured to determine a second target requested torque according to a second basic torque, a second actual vehicle speed and a target vehicle speed; The request torque sending subunit is further used to send a second target request torque to the motor controller until the vehicle travels based on the target vehicle speed.
[0078] Optionally, the basic torque determination subunit is specifically used for: determining a corresponding third basic requested torque according to the first actual vehicle speed, wherein the third basic requested torque is positively correlated with the first actual vehicle speed; The torque coefficient is determined according to the brake pedal opening, and the torque coefficient is negatively correlated with the brake pedal opening; The first base torque is determined based on the third base request torque and the torque coefficient.
[0079] Optionally, the target torque determination subunit is specifically used for: calculating a vehicle speed difference between the target vehicle speed and the first actual vehicle speed; The vehicle speed difference is input into the PID controller to obtain the requested torque increment; A first target requested torque is determined according to the first base torque and the requested torque increase.
[0080] Optionally, the acquiring unit 501 is specifically configured to: Receive brake master cylinder pressure signal from electronic stability control system; Determine the brake pedal opening according to the brake master cylinder pressure signal; or, Receives brake pedal opening from the electronic brake system.
[0081] See also Figure 7 Based on the same inventive concept, the embodiment of the present application further provides a vehicle controller, the vehicle controller includes at least one processor 601, the processor 601 is used to execute the computer program stored in the memory, and implement the embodiment of the present application as provided in Figure 1-5 Flow chart of the vehicle speed control method shown in FIG.
[0082] Optionally, the processor 601 may specifically be a central processing unit, a specific ASIC, or one or more integrated circuits for controlling program execution.
[0083] Optionally, the vehicle controller may further include a memory 602 connected to at least one processor 601, and the memory 602 may include ROM, RAM, and disk storage. The memory 602 is used to store data required by the processor 601 when it is running, that is, it stores instructions that can be executed by at least one processor 601. At least one processor 601 executes the instructions stored in the memory 602 to execute the following steps: Figure 1-5 The method shown. Wherein, the number of memories 602 is one or more. Wherein, the number of memories 602 is one or more.
[0084] See also Figure 8 Based on the same inventive concept, the present application embodiment provides a vehicle, which includes Figure 7 The vehicle controller shown in the figure can be a pure electric vehicle, a plug-in hybrid vehicle, or an extended-range vehicle, and this application does not impose any special restrictions on this.
[0085] The present application also provides a computer storage medium, wherein the computer storage medium stores computer instructions, and when the computer instructions are executed on a computer, the computer executes Figure 1-5 method.
[0086] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this specification should be included in the scope of protection of this specification.
Claims
1. A vehicle speed control method, characterized in that: The method comprises: Obtain brake pedal switch signal and brake pedal opening; In response to the brake pedal switch signal indicating that the brake pedal is not enabled, the vehicle is controlled to travel based on a target vehicle speed according to the brake pedal opening, wherein the target vehicle speed is negatively correlated with the brake pedal opening, and the target vehicle speed is not greater than a set vehicle speed threshold.
2. The method according to claim 1, characterized in that The set vehicle speed threshold is the maximum vehicle speed corresponding to the creep function.
3. The method according to claim 2, characterized in that Controlling the vehicle to travel based on a target vehicle speed according to the brake pedal opening degree includes: determining the target vehicle speed of the creep function according to the brake pedal opening; The creep function is activated to control the vehicle to travel based on the target vehicle speed.
4. The method according to claim 3, characterized in that Controlling the vehicle to travel based on the target vehicle speed includes: Acquiring a first actual vehicle speed of the vehicle; determining a first basic requested torque according to the first actual vehicle speed and the brake pedal opening, wherein the first basic requested torque is positively correlated with the first actual vehicle speed and negatively correlated with the brake pedal opening; determining a first target requested torque according to the first basic requested torque, the first actual vehicle speed, and the target vehicle speed; sending the first target requested torque to a motor controller; Acquiring a second actual vehicle speed of the vehicle; determining a second basic requested torque according to the second actual vehicle speed and the brake pedal opening, wherein the second basic requested torque is positively correlated with the second actual vehicle speed and negatively correlated with the brake pedal opening; determining a second target requested torque according to the second basic torque, the second actual vehicle speed and the target vehicle speed; The second target request torque is sent to a motor controller until the vehicle travels based on the target vehicle speed.
5. The method according to claim 4, characterized in that Determining a first basic requested torque according to the first actual vehicle speed and the brake pedal opening includes: determining a corresponding third basic requested torque according to the first actual vehicle speed, wherein the third basic requested torque is positively correlated with the first actual vehicle speed; determining a torque coefficient according to the brake pedal opening, wherein the torque coefficient is negatively correlated with the brake pedal opening; The first base torque is determined according to the third base request torque and the torque coefficient.
6. The method according to claim 4, characterized in that Determining a first target requested torque according to the first basic requested torque, the first actual vehicle speed, and the target vehicle speed includes: calculating a vehicle speed difference between the target vehicle speed and the first actual vehicle speed; Inputting the vehicle speed difference into a PID controller to obtain a requested torque increment; The first target requested torque is determined according to the first base torque and the requested torque increase.
7. The method according to any one of claims 1 to 6, characterized in that: Get the brake pedal opening, including: Receive brake master cylinder pressure signal from electronic stability control system; Determine the brake pedal opening according to the brake master cylinder pressure signal; or The brake pedal opening is received from an electronic brake system.
8. A vehicle speed control device, characterized in that: The device comprises: An acquisition unit, used for acquiring a brake pedal switch signal and a brake pedal opening; A control unit is used to control the vehicle to travel based on a target vehicle speed according to the brake pedal opening in response to the brake pedal switch signal indicating that the brake pedal is not enabled, wherein the target vehicle speed is not greater than a set vehicle speed threshold.
9. A vehicle controller, characterized in that: The vehicle controller includes a memory for storing computer program instructions and a processor for executing program instructions, wherein when the computer program instructions are executed by the processor, the vehicle controller is triggered to execute the steps of the method as described in any one of claims 1-7.
10. A vehicle, characterized in that: The vehicle includes a vehicle controller as described in claim 9.