Longitudinal vehicle speed drive control method and device

Abstract

This application discloses a longitudinal vehicle speed drive control method and apparatus. It includes: acquiring a target vehicle speed, a preset acceleration, and a current first speed of the vehicle; based on the target vehicle speed, preset acceleration, and first speed, obtaining the acceleration time for the vehicle to accelerate from the first speed to the target speed; based on the acceleration time, calculating a second speed of the vehicle at each time step within the acceleration time, and a first acceleration of the vehicle at every two adjacent time steps; based on the first acceleration and a preset first correspondence between vehicle acceleration and torque, obtaining a first torque corresponding to the first acceleration; for each time step, based on the second speed, the first speed of the vehicle at the time step, and the first torque, determining a target torque of the vehicle at the time step, wherein the target torque is used to drive the vehicle. This aims to maintain acceleration stability during the vehicle's acceleration process and reduce speed overshoot, speed tracking lag, and oscillation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicles, and particularly relates to a longitudinal vehicle speed driving control method and device. BACKGROUND

[0002] The driving control of the longitudinal vehicle speed of an electric vehicle is a key link of automatic driving motion control, and the control effect of the longitudinal vehicle speed directly affects the pose of the electric vehicle and is one of decisive factors of driving efficiency and safety.

[0003] At present, the driving control of the longitudinal vehicle speed of an electric vehicle is to control the motor to drive the wheels to rotate based on the torque calculated according to the deviation between the target vehicle speed and the current vehicle speed measured in real time by using the PI controller feedback, and to perform certain limiting on the output torque to ensure safety.

[0004] The above driving control method of the longitudinal vehicle speed may cause step changes in the input of the PI controller due to the switching of the target vehicle speed, but the output torque and the acceleration generated by the response acting on the vehicle cannot cause step changes in the vehicle speed, so the control effect of the controller will have defects when the target vehicle speed is switched, such as vehicle speed tracking lag, large overshoot and vehicle speed oscillation near the target speed, which is not conducive to the safe driving of the vehicle. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a longitudinal vehicle speed driving control method and device to maintain the acceleration stability in the acceleration process of the vehicle and reduce the speed overshoot, speed tracking lag and oscillation.

[0006] The technical solution of the present application is as follows:

[0007] In a first aspect, a longitudinal vehicle speed driving control method is provided, which comprises:

[0008] obtaining a target vehicle speed, a preset acceleration and a first speed of a vehicle;

[0009] obtaining an acceleration time of the vehicle from the first speed to the target speed based on the target vehicle speed, the preset acceleration and the first speed;

[0010] calculating a second speed of the vehicle at each time step within the acceleration time and a first acceleration of the vehicle at each adjacent two time steps based on the acceleration time;

[0011] obtaining a first torque corresponding to the first acceleration based on the first acceleration and a first correspondence relationship between the acceleration of the vehicle and the torque preset in advance;

[0012] For each time step, a target torque of the vehicle at the time step is determined based on the second speed and a first speed of the vehicle at the time step, wherein the target torque is used to drive the vehicle to travel.

[0013] In a second aspect, a longitudinal vehicle speed driving control device is provided, and the device comprises:

[0014] An acquisition module is configured to acquire a target vehicle speed, a preset acceleration and a first speed of the vehicle;

[0015] A first determination module is configured to obtain an acceleration time of the vehicle from the first speed to the target vehicle speed based on the target vehicle speed, the preset acceleration and the first speed;

[0016] A first calculation module is configured to calculate a second speed of the vehicle at each time step within the acceleration time and a first acceleration of the vehicle at each adjacent two time steps based on the acceleration time;

[0017] A second determination module is configured to obtain a first torque corresponding to the first acceleration based on the first acceleration and a preset first correspondence between the acceleration of the vehicle and the torque;

[0018] A third determination module is configured to determine a target torque of the vehicle at each time step based on the second speed and a first speed of the vehicle at the time step, wherein the target torque is used to drive the vehicle to travel.

[0019] In a third aspect, an electronic device is provided, which comprises a processor, a memory, and a program or instruction stored in the memory and executable on the processor, and the program or instruction is executed by the processor to implement the steps of the longitudinal vehicle speed driving control method according to any one of the embodiments of the present application.

[0020] In a fourth aspect, a readable storage medium is provided, and the readable storage medium stores a program or instruction, and the program or instruction is executed by a processor to implement the steps of the longitudinal vehicle speed driving control method according to any one of the embodiments of the present application.

[0021] In a fifth aspect, a computer program product is provided, and the instructions in the computer program product are executed by a processor of an electronic device to enable the electronic device to perform the steps of the longitudinal vehicle speed driving control method according to any one of the embodiments of the present application.

[0022] The technical solutions provided by the embodiments of the present application at least bring the following beneficial effects:

[0023] In the embodiment of the present application, the acceleration time of the vehicle from the first speed to the target speed is obtained based on the target speed of the vehicle, the preset acceleration and the first speed of the vehicle, then the second speed of the vehicle at each time step in the acceleration time is calculated, for each time step, the target torque of the vehicle at the time step is determined based on the second speed and the first speed of the vehicle at the time step, so as to drive the vehicle to travel based on the target torque, thus by calculating the second speed of the vehicle at each time step in the acceleration time of the vehicle from the first speed to the target speed, and then determining the target torque of the vehicle at each time step according to the second speed, the step of the target speed is eliminated, the speed is smoothed, the acceleration in the acceleration process is maintained stable, the problems of speed overshoot, speed tracking lag and oscillation are reduced, smooth and accurate longitudinal speed control is realized, in addition, the first acceleration of the vehicle at each adjacent two time steps in the acceleration time is calculated based on the acceleration time, then the first torque corresponding to the first acceleration is obtained based on the first acceleration and the first preset corresponding relationship between the acceleration and the torque of the vehicle, the target torque of the vehicle at the time step is determined based on the second speed, the first speed of the vehicle at the time step and the first torque, thus the determined target torque is more accurate, and the problems of speed overshoot, speed tracking lag and oscillation are further reduced by the acceleration feedforward module.

[0024] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings incorporated into the specification and forming a part thereof illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application, and do not limit the present application.

[0026] Figure 1 is a structural schematic diagram of a longitudinal speed driving control system according to an embodiment of the present application;

[0027] Figure 2 is a flowchart of a longitudinal speed driving control method according to an embodiment of the first aspect of the present application;

[0028] Figure 3 is a working flowchart of a longitudinal speed driving control system according to an embodiment of the first aspect of the present application;

[0029] Figure 4 is a curve diagram of the change of vehicle speed in the longitudinal speed control process according to an embodiment of the first aspect of the present application;

[0030] Figure 5 is a curve diagram of the change of acceleration in the longitudinal speed control process according to an embodiment of the first aspect of the present application;

[0031] Figure 6 is a structural schematic diagram of a longitudinal vehicle speed drive control device provided by a second aspect embodiment of the present application;

[0032] Figure 7 is a structural schematic diagram of an electronic device provided by a third aspect embodiment of the present application. DETAILED DESCRIPTION

[0033] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings. It should be understood that the specific embodiments described herein are intended to explain the present application only, not to limit the present application. The present application can be implemented without some of these specific details by those skilled in the art. The following description of the embodiments is merely to provide a better understanding of the present application by showing examples of the present application.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The implementation described in the following exemplary embodiments does not represent all implementations consistent with the present application. Rather, they are merely examples consistent with some aspects of the present application as detailed in the appended claims.

[0035] As described in the background section, there are problems in the prior art that the vehicle speed tracking is lagging, a large overshoot is generated, and the vehicle speed oscillates near the target speed, which is not conducive to the safe driving of the vehicle. To solve the above problems, the embodiments of the present application provide a longitudinal vehicle speed driving control method and device. By obtaining the target vehicle speed, the preset acceleration, and the current first speed of the vehicle, the acceleration time of the vehicle from the first speed to the target speed is obtained. Then, the second speed of the vehicle at each time step within the acceleration time is calculated. For each time step, the target torque of the vehicle at the time step is determined based on the second speed and the first speed of the vehicle at the time step, so as to drive the vehicle to travel based on the target torque. In this way, by calculating the second speed of the vehicle at each time step within the acceleration time from the first speed to the target speed, and then determining the target torque of the vehicle at each time step according to the second speed and the first speed of the vehicle at the time step, the step of the target speed is eliminated, the vehicle speed is smoothed, the acceleration during the acceleration process is stabilized, the problems of speed overshoot, speed tracking lag, and oscillation are reduced, and smooth and accurate longitudinal vehicle speed control is achieved. In addition, by calculating the first acceleration of the vehicle at each adjacent two time steps within the acceleration time based on the acceleration time, and then obtaining the first torque corresponding to the first acceleration based on the first acceleration and the preset first correspondence between the acceleration of the vehicle and the torque, the target torque of the vehicle at the time step is determined based on the second speed, the first speed of the vehicle at the time step, and the first torque. The target torque determined in this way is more accurate, and the problems of speed overshoot, speed tracking lag, and oscillation are further reduced by the acceleration feedforward module.

[0036] The longitudinal vehicle speed driving control method provided by the embodiments of the present application will be described in detail below in conjunction with the drawings, specific embodiments, and application scenarios.

[0037] Before introducing the technical solutions of the embodiments of the present application, first introduce the terms related to the embodiments of the present application:

[0038] Vehicle speed tracking lag. When a target vehicle speed is given, the actual running speed of the vehicle will not jump to the target vehicle speed immediately, so there is a vehicle speed tracking lag.

[0039] Overshoot. The amount of speed exceeding the target speed. For example, the target speed of a vehicle is 4 km / h, and the current speed is 0 km / h. According to a certain acceleration, the speed is increased from the current 0 km / h to 4 km / h. Due to inertia and other reasons, the speed will first increase to 4 km / h during the speed-up process, and then continue to accelerate to a certain speed, such as 5 km / h, and then slowly decrease to 4 km / h. Therefore, during the speed-up process, the speed exceeds the target speed, and the amount of speed exceeding the target speed is the overshoot, which is 5-4=1 km / h.

[0040] Continue the above example, if the vehicle speed is first accelerated to 4km / h, then continues to accelerate to 5km / h, and then slowly reduces to 4km / h, the vehicle speed will oscillate around 4km / h and will not stabilize at 4km / h.

[0041] Before introducing the longitudinal vehicle speed driving control method provided by the embodiments of the present application, first introduce the longitudinal vehicle speed driving control system for implementing the longitudinal vehicle speed driving control method of the embodiments of the present application, as shown in the figure, the longitudinal vehicle speed driving control system 100 can include a vehicle speed first-order trajectory planning module 110, an acceleration feedforward module 120, a proportional integral (PI) controller 130, an actuator 140 and a controlled object 150. Figure 1

[0042] The vehicle speed first-order trajectory planning module 110 is used for vehicle speed tracking, converts the step input into a slope input that fits the physical reality, and reduces the tracking lag, tuning and oscillation caused by the step input. The working process of the vehicle speed first-order trajectory planning module 110 is described in detail in subsequent embodiments.

[0043] The acceleration feedforward module 120 is used to convert the slope planned by the vehicle speed first-order trajectory planning module 110 into acceleration as the input of the acceleration feedforward module 120, to realize acceleration control in the tracking process. The introduction of the acceleration feedforward module 120 reduces the lag and tuning of the PI controller.

[0044] The PI controller 130 works in the same way as the existing PI controller, that is, the target speed and the measured vehicle speed are calculated for deviation, and the torque of the vehicle is obtained based on the deviation.

[0045] The actuator 140 can be a motor or other driving device for driving the vehicle to run.

[0046] The controlled object 150 can be a vehicle.

[0047] In some embodiments of the present application, the vehicle speed first-order trajectory planning module 110, the acceleration feedforward module 120 and the PI controller 130 can jointly constitute a controller, which gives an input value of the motor torque according to the input target vehicle speed and the measured vehicle speed, and the motor executes the torque input instruction to drive the vehicle to generate acceleration to track the target vehicle speed.

[0048] The following describes in detail how each module in the longitudinal vehicle speed driving control system implements the longitudinal vehicle speed driving control method provided by the embodiments of the present application.

[0049] Figure 2 ​is a flowchart of a longitudinal vehicle speed driving control method provided by an embodiment of the present application. The execution subject of the longitudinal vehicle speed driving control method can be the longitudinal vehicle speed driving control system described above Figure 1 , and more specifically can be the controller composed of the vehicle speed first-order trajectory planning module 110, the acceleration feedforward module 120, and the PI controller 130. As shown in Figure 2 , the longitudinal vehicle speed driving control method provided by an embodiment of the present application can include steps 210-250.

[0050] Step 210, obtaining a target vehicle speed, a preset acceleration, and a first speed of the vehicle.

[0051] The target vehicle speed can be a final vehicle speed that the vehicle wants to reach. For example, it can be 4 km / h.

[0052] The preset acceleration can be a pre-set acceleration, for example, it can be 2 km / h 2 .

[0053] The first speed can be the current speed of the vehicle.

[0054] In some embodiments of the present application, the first speed can be obtained in real time or from a database. For example, it can be obtained in real time based on sensors of the vehicle, or it can be obtained from a memory, which is not limited here.

[0055] Step 220, obtaining an acceleration time for the vehicle to accelerate from the first speed to the target speed based on the target vehicle speed, the preset acceleration, and the first speed.

[0056] The acceleration time can be the time for the vehicle to accelerate from the first speed to the target speed.

[0057] Step 230, calculating a second speed of the vehicle at each time step within the acceleration time and a first acceleration of the vehicle at each adjacent two time steps based on the acceleration time.

[0058] The time step can be a pre-set unit time, for example, the speed of the vehicle can be calculated every 2 seconds, and the time step is 2 seconds.

[0059] The second speed can be the speed of the vehicle at each time step within the acceleration time.

[0060] In an example, if the target speed of the vehicle is 4 km / h, the current first speed is 0 km / h, and the preset acceleration is 2 km / h 2 , the acceleration time is 2 h, and if the time step is half an hour, the second speed of the vehicle is calculated every half an hour.

[0061] The first acceleration can be an acceleration of the vehicle at every two adjacent time steps within the acceleration time.

[0062] In some embodiments of the present application, the output of the vehicle speed first-order trajectory planning module 110, in addition to the second speed, further includes a first acceleration of the vehicle at every two adjacent time steps.

[0063] Step 240, based on the first acceleration and a first preset correspondence between the acceleration and the torque of the vehicle, a first torque corresponding to the first acceleration is obtained.

[0064] The first torque can be a torque corresponding to the first acceleration.

[0065] After the vehicle speed first-order trajectory planning module 110 outputs the first acceleration, the first acceleration can be input to the acceleration feedforward module 120. According to the first acceleration, the acceleration feedforward module 120 can obtain a first torque corresponding to the first acceleration, that is, the input of the acceleration feedforward module 120 is the first acceleration, and the output is the torque.

[0066] Step 250, for each time step, based on the second speed and the first speed of the vehicle at the time step, and the first torque, a target torque of the vehicle at the time step is determined.

[0067] The target torque can be a torque determined based on the second speed and the first speed of the vehicle at the time step, and the target torque is used to drive the vehicle to travel at the current time.

[0068] In some embodiments of the present application, the execution subject of the above steps 210-230 is the vehicle speed first-order trajectory planning module 110, and the input of the vehicle speed first-order trajectory planning module 110 is the target speed, and the output is the second speed.

[0069] In some embodiments of the present application, in order to further accurately determine the target torque, the determination of the target torque of the vehicle at the time step based on the second speed and the first speed of the vehicle at the time step, and the first torque can specifically include:

[0070] Determine a second torque of the vehicle at the time step based on the second speed and the first speed of the vehicle at the time step;

[0071] Determine the target torque of the vehicle at the time step based on the first torque and the second torque.

[0072] The second torque can be a torque of the vehicle at the time step determined according to the second speed and the first speed of the vehicle at the time step.

[0073] In some embodiments of the present application, with reference to Figure 3, the motor executes the target torque to push the vehicle body to generate acceleration, track the target speed, and can feed back the measured current vehicle speed to the controller to form a closed loop. That is, a target torque is determined at each time step, the motor executes the target torque at this moment to push the vehicle body to generate acceleration, track the target speed, and measure the current vehicle speed in real time, and can feed back the measured current vehicle speed to the controller as the first speed, and the second speed output by the vehicle speed first trajectory planning module 110 to calculate the second torque. This cycle is repeated until the speed of the vehicle reaches the target speed.

[0074] It should be noted that the parameters of the PI controller can be determined by experiments, and the corresponding relationship between the speed deviation and the torque is provided.

[0075] In the embodiments of the present application, the second torque of the vehicle at the time step is determined based on the second speed and the first speed of the vehicle at the time step, the target torque of the vehicle at the time step is determined based on the first torque and the second torque, and the target torque is determined by the first torque and the second torque, thereby improving the accuracy of the target torque.

[0076] In some embodiments of the present application, in order to further accurately determine the target torque, the target torque of the vehicle at the time step is determined based on the first torque and the second torque, and specifically can include:

[0077] superimposing the first torque and the second torque to obtain a third torque;

[0078] determining the third torque as the target torque of the vehicle at the time step.

[0079] The third torque can be the torque obtained by superimposing the first torque and the second torque.

[0080] In the embodiments of the present application, the superimposed torque of the first torque and the second torque is determined as the target torque of the vehicle at the time step, thereby improving the accuracy of the target torque.

[0081] In some embodiments of the present application, the second torque of the vehicle at the time step is determined based on the second speed and the first speed of the vehicle at the time step, and specifically can include:

[0082] calculating a target speed deviation between the second speed and the first speed of the vehicle at the time step;

[0083] determining the second torque corresponding to the target speed deviation at the time step based on the target speed deviation and a second corresponding relationship between the preset speed deviation and the torque.

[0084] The target speed deviation can be a speed deviation between the second speed and the first speed of the vehicle at the time step.

[0085] In some embodiments of the present application, after the vehicle speed first-order trajectory planning module 110 outputs the second speed at each time step, the measured current first speed of the vehicle is obtained, and then the target speed deviation between the second speed and the first speed is calculated, and the target speed deviation is input into the PI controller, and the PI controller can calculate the second torque according to the target speed deviation. That is, the input of the PI controller is the target speed deviation between the second speed at each time step output by the vehicle speed first-order trajectory planning module 110 and the measured first speed, and the output is the second torque.

[0086] In embodiments of the present application, by calculating the target speed deviation between the second speed and the first speed of the vehicle at the time step, based on the target speed deviation and the second correspondence relationship between the pre-set speed deviation and the torque, the second torque corresponding to the target speed deviation at the time step can be accurately determined.

[0087] The following will be described in detail how the acceleration feedforward module 120 outputs the first torque based on the input first acceleration:

[0088] In some embodiments of the present application, before the first torque corresponding to the first acceleration is obtained, the method further comprises:

[0089] Obtaining a relationship between the angular velocity of the motor rotation, the moment of inertia, the electromagnetic torque and the damping torque;

[0090] According to the relationship, a first correspondence relationship between the acceleration and the torque is obtained.

[0091] The relationship between the angular velocity of the motor rotation, the moment of inertia, the electromagnetic torque and the damping torque can be as shown in the following formula (1):

[0092]

[0093] Wherein, w is the angular velocity of the motor rotation; J is the moment of inertia; T is the electromagnetic torque; T r is the damping torque.

[0094] In an ideal state, the moment of inertia and the damping torque in formula (1) are constant values, that is, they do not change. Therefore, a plurality of groups of electromagnetic torque can be provided to determine the corresponding motor rotation angular acceleration experiment to calibrate the coefficients of the linear expression of the aforementioned motor rotation angular acceleration and electromagnetic torque.

[0095] In some embodiments of the present application, the first correspondence relationship between the acceleration and the torque according to the relationship can specifically include:

[0096] obtain a plurality of sets of historical experimental data, wherein each set of historical experimental data comprises a historical electromagnetic torque and a historical angular velocity;

[0097] substitute the historical electromagnetic torque and the historical angular velocity in each set of historical experimental data into the relationship to obtain a first correspondence between the acceleration of the vehicle and the torque.

[0098] The historical electromagnetic torque can be an electromagnetic torque obtained before the current time.

[0099] The historical angular velocity can be an angular velocity of the motor obtained before the current time.

[0100] In some embodiments of the present application, a plurality of sets of historical experimental data obtained can be substituted into formula (1) to obtain the first correspondence between the acceleration of the vehicle and the torque.

[0101] In some embodiments of the present application, the step of substituting the historical electromagnetic torque and the historical angular velocity in each set of historical experimental data into the relationship to obtain the first correspondence between the acceleration of the vehicle and the torque can specifically include:

[0102] substitute the historical electromagnetic torque and the historical angular velocity in each set of historical experimental data into the relationship to obtain a first coefficient of the electromagnetic torque and a second coefficient of the angular velocity in the relationship;

[0103] obtain a third correspondence between the angular velocity and the electromagnetic torque based on the first coefficient and the second coefficient;

[0104] substitute the acceleration of the vehicle with the angular velocity to obtain the first correspondence between the acceleration of the vehicle and the torque.

[0105] The first coefficient and the second coefficient can be respectively a coefficient of the angular velocity and a coefficient of the electromagnetic torque in formula (1) obtained after a plurality of sets of historical experimental data are substituted into formula (1).

[0106] The third correspondence can be a correspondence between the angular velocity and the electromagnetic torque determined after the historical electromagnetic torque and the historical angular velocity are substituted into the relationship to obtain a first coefficient of the electromagnetic torque and a second coefficient of the angular velocity in the relationship.

[0107] In some embodiments of the present application, a plurality of sets of historical experimental data can be substituted into formula (1), so that the first coefficient of the angular velocity and the second coefficient of the electromagnetic torque in formula (1) can be obtained, and thus the third correspondence between the angular velocity and the electromagnetic torque can be determined.

[0108] Then, according to the first correspondence between the acceleration and the torque of the vehicle obtained in the previous step, the first acceleration output by the vehicle speed first-order trajectory planning module 110 is taken as an input, and the torque is taken as an output to establish the acceleration feedforward module 120.

[0109] In the embodiments of the present application, the first correspondence is obtained through a plurality of sets of historical experimental data, and the acceleration feedforward module is established, so that the first torque can be quickly and accurately obtained based on the acceleration feedforward module.

[0110] In some embodiments of the present application, when the acceleration of the vehicle is replaced by the angular velocity, the driving state of the vehicle needs to meet certain conditions. Specifically, the first correspondence between the acceleration and the torque of the vehicle is obtained by replacing the acceleration of the vehicle by the angular velocity, and specifically can include:

[0111] In the case where the driving state of the vehicle meets the preset driving state, the acceleration of the vehicle is replaced by the angular velocity to obtain the first correspondence between the acceleration and the torque of the vehicle.

[0112] The preset driving state can be a driving state in which the acceleration of the vehicle can be replaced by the angular velocity, which can be, for example, a non-conventional driving condition such as wheel slip or lock. That is, under the condition that wheel slip or lock is not considered, the motor angular velocity and angular acceleration can be approximately equal to the wheel angular velocity and angular acceleration, and the wheel speed and acceleration can be converted into the vehicle speed and acceleration, so that the motor angular acceleration in the third correspondence obtained by the calibration can be replaced by the vehicle acceleration through transformation, thereby establishing a linear expression of the vehicle acceleration and the electromagnetic torque.

[0113] In the embodiments of the present application, in the case where the driving state of the vehicle meets the preset driving state, the acceleration of the vehicle is replaced by the angular velocity to obtain the first correspondence between the acceleration and the torque of the vehicle, so that the first correspondence between the acceleration and the torque of the vehicle can be accurately determined. In some embodiments of the present application, in order to better understand the technical solutions of the embodiments of the present application, another implementable manner of the longitudinal vehicle speed driving control method is also provided. The longitudinal vehicle speed driving control method provided by the embodiments of the present application can include the following steps:

[0114] Firstly, the vehicle speed first-order trajectory planning module converts the input step target speed into a corresponding ramp speed input according to a given preset acceleration, and simultaneously outputs a first acceleration.

[0115] Secondly, the PI controller outputs a feedback second torque according to the deviation between the second speed input and the measured first speed.

[0116] Thirdly, the first acceleration is input into the acceleration feedforward module, and a corresponding feedforward torque, i.e., a first torque, is output.

[0117] Fourthly, the feedback torque (i.e., the second torque) and the feedforward torque (i.e., the first torque) are superimposed as a target torque input of the motor, so as to drive the vehicle to change the motion state, track the vehicle speed input, and feedback the measured vehicle speed.

[0118] In one example, the target speed is set as 10 m / s, the preset acceleration is 0.8 m / s2, the vehicle speed change curve in the control process is as shown in Figure 4 , and the acceleration change curve is as shown in Figure 5 , which indicates that the longitudinal vehicle speed drive control method proposed in the embodiment can realize smooth and accurate vehicle speed control.

[0119] In the embodiment, the first-order trajectory planning is performed on the input target speed, so as to avoid the hysteresis, overshoot and oscillation caused by the step change of the input target speed. The acceleration feedforward module is constructed based on the experiment calibration, the feedforward torque is calculated based on the preset acceleration, and the feedforward torque is superimposed with the feedback torque output by the PI control, so as to further reduce the hysteresis and overshoot caused by the feedback and integration. In this way, the feedforward and feedback are combined to ensure that the controller is robust enough while reducing the hysteresis and overshoot caused by the feedback and integration, so as to realize smooth and accurate vehicle speed control.

[0120] It should be noted that the longitudinal vehicle speed drive control method provided in the embodiment can be a longitudinal vehicle speed drive control device, or a control module in the longitudinal vehicle speed drive control device for executing the longitudinal vehicle speed drive control method.

[0121] Based on the same inventive concept as the longitudinal vehicle speed drive control method described above, the application further provides a longitudinal vehicle speed drive control device. The longitudinal vehicle speed drive control device provided in the embodiment will be described in detail below. Figure 6

[0122] Figure 6 is a structural schematic diagram of a longitudinal vehicle speed drive control device according to an example embodiment.

[0123] As shown in Figure 6 , the longitudinal vehicle speed drive control device 600 can include:

[0124] The acquisition module 610 is configured to acquire a target vehicle speed, a preset acceleration and a first speed of a vehicle.

[0125] The first determination module 620 is configured to obtain an acceleration time of the vehicle from the first speed to the target speed based on the target vehicle speed, the preset acceleration and the first speed.

[0126] ​The first calculating module 630 is configured to calculate, based on the acceleration time, a second speed of the vehicle at each time step within the acceleration time and a first acceleration of the vehicle at each adjacent two time steps;

[0127] The second determining module 640 is configured to obtain a first torque corresponding to the first acceleration based on the first acceleration and a preset first correspondence between the acceleration and the torque of the vehicle.

[0128] The third determining module 650 is configured to determine, for each time step, a target torque of the vehicle at the time step based on the second speed and a first speed of the vehicle at the time step, wherein the target torque is used to drive the vehicle to travel.

[0129] In the embodiments of the present application, the acceleration time of the vehicle from the first speed to the target speed is obtained based on the target speed of the vehicle, the preset acceleration and the first speed of the vehicle, then the second speed of the vehicle at each time step within the acceleration time is calculated, for each time step, the target torque of the vehicle at the time step is determined based on the second speed and the first speed of the vehicle at the time step, and the vehicle is driven to travel based on the target torque, thus by calculating the second speed of the vehicle at each time step within the acceleration time of the vehicle from the first speed to the target speed, and then determining the target torque of the vehicle at each time step according to the second speed, the step of the target speed is eliminated, the speed is smoothed, the acceleration in the acceleration process is stabilized, the problems of speed overshoot, speed tracking lag and oscillation are reduced, smooth and accurate longitudinal speed control is realized, in addition, the first acceleration of the vehicle at each adjacent two time steps within the acceleration time is calculated based on the acceleration time, then the first torque corresponding to the first acceleration is obtained based on the first acceleration and the preset first correspondence between the acceleration and the torque of the vehicle, the target torque of the vehicle at the time step is determined based on the second speed, the first speed of the vehicle at the time step and the first torque, thus the determined target torque is more accurate, and the problems of speed overshoot, speed tracking lag and oscillation are further reduced by the acceleration feedforward module.

[0130] In some embodiments of the present application, in order to further accurately determine the target torque, the third determining module 650 can specifically include:

[0131] The first determining unit is configured to determine, based on the second speed and the first speed of the vehicle at the time step, a second torque of the vehicle at the time step;

[0132] The second determining unit is configured to determine, based on the first torque and the second torque, the target torque of the vehicle at the time step.

[0133] In some embodiments of the present application, in order to further accurately determine the target torque, the second determining unit can be specifically configured to:

[0134] superimpose the first torque and the second torque to obtain a third torque;

[0135] determine the third torque as the target torque of the vehicle at the time step.

[0136] In some embodiments of the present application, the first determining unit can be specifically configured to:

[0137] calculate a target speed deviation between the second speed and a first speed of the vehicle at the time step;

[0138] determine a second torque corresponding to the target speed deviation at the time step based on the target speed deviation and a second correspondence relationship between a preset speed deviation and a torque.

[0139] In some embodiments of the present application, the obtaining module 610 can be further configured to obtain a relationship between an angular velocity of motor rotation, a moment of inertia, an electromagnetic torque and a damping torque; wherein the moment of inertia and the damping torque in the relationship are constant values;

[0140] The longitudinal vehicle speed driving control device described above can further include:

[0141] A fourth determining module configured to obtain a first correspondence relationship between acceleration and torque according to the relationship.

[0142] In some embodiments of the present application, the obtaining module 610 can be further configured to obtain a plurality of sets of historical experimental data; wherein each set of historical experimental data includes a historical electromagnetic torque and a historical angular velocity;

[0143] The fourth determining module can be specifically configured to substitute the historical electromagnetic torque and the historical angular velocity in each set of historical experimental data into the relationship to obtain a first correspondence relationship between acceleration and torque of the vehicle.

[0144] In some embodiments of the present application, the fourth determining module can be specifically configured to:

[0145] substitute the historical electromagnetic torque and the historical angular velocity in each set of historical experimental data into the relationship to obtain a first coefficient of the electromagnetic torque and a second coefficient of the angular velocity in the relationship;

[0146] obtain a third correspondence relationship between the angular velocity and the electromagnetic torque based on the first coefficient and the second coefficient;

[0147] The acceleration of the vehicle is replaced by the angular velocity to obtain a first correspondence between the acceleration of the vehicle and the torque.

[0148] In some embodiments of the present application, the fourth determining module can be specifically configured to: in a case where the driving state of the vehicle meets a preset driving state, replace the acceleration of the vehicle by the angular velocity to obtain a first correspondence between the acceleration of the vehicle and the torque.

[0149] In some embodiments of the present application, a relationship among the angular velocity of the motor rotation, the moment of inertia, the electromagnetic torque and the damping torque is as follows:

[0150]

[0151] wherein w is the angular velocity of the motor rotation, J is the moment of inertia, T is the electromagnetic torque, and T is the damping torque. r

[0152] The longitudinal vehicle speed driving control device provided by the embodiments of the present application can be used to execute the longitudinal vehicle speed driving control method provided by each method embodiment, and the implementation principles and technical effects are similar, and thus will not be described here again for brevity.

[0153] Based on the same inventive concept, the embodiments of the present application further provide an electronic device.

[0154] Figure 7 is a structural schematic diagram of an electronic device provided by the embodiments of the present application. As shown in Figure 7 The electronic device can include a processor 701 and a memory 702 storing computer programs or instructions.

[0155] Specifically, the processor 701 can include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or can be configured as one or more integrated circuits implementing the embodiments of the present application.

[0156] ​The memory 702 can include mass storage for data or instructions. As an example and not by way of limitation, the memory 702 can include a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disc (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a solid-state drive (SSD), a USB drive, or a combination of two or more of these. Where appropriate, the memory 702 can include removable or non-removable (or fixed) media. Where appropriate, the memory 702 can be internal or external to the integrated gateway disaster recovery device. In particular embodiments, the memory 702 is non-volatile, solid-state memory. The memory can include read-only memory (ROM), random-access memory (RAM), magnetic disk storage mediums, optical storage mediums, flash memory devices, electrical, optical, or other physically tangible / moφhological memory storage devices. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software that, when executed (by one or more processors), is operable to cause the operations described above as being provided by the longitudinal vehicle speed drive control method.

[0157] The processor 701 implements any one of the longitudinal vehicle speed drive control methods in the above embodiments by reading and executing computer program instructions stored in the memory 702.

[0158] In one example, the electronic device can further include a communication interface 703 and a bus 710. As shown, the processor 701, the memory 702, and the communication interface 703 are connected by the bus 710 and complete communication with each other. Figure 7

[0159] The communication interface 703 is mainly used to realize the communication between the modules, devices, units and / or devices in the embodiments of the present application.

[0160] ​Bus 710 includes hardware, software, or both, to couple electronic devices to each other in a network. While Figure 7 illustrates a bus, other interconnects that are used to interconnect various hardware components can be utilized (e.g., 12C, PCI, SCSI, Bluetooth®, etc.). Although this disclosure describes and illustrates a particular bus, this disclosure contemplates any suitable bus or interconnect.

[0161] The electronic device can perform the longitudinal vehicle speed drive control method in the embodiments of the present application, thereby implementing the longitudinal vehicle speed drive control method described in any of the above embodiments.

[0162] In addition, in combination with the longitudinal vehicle speed drive control method in the above embodiments, the embodiments of the present application can provide a readable storage medium to implement. The readable storage medium has program instructions stored thereon; the program instructions are executed by a processor to implement any of the longitudinal vehicle speed drive control methods in the above embodiments.

[0163] In addition, in combination with the longitudinal vehicle speed drive control method in the above embodiments, the embodiments of the present application can provide a computer program product to implement. The instructions in the computer program product are executed by the processor of the electronic device, so that the electronic device can perform any of the longitudinal vehicle speed drive control methods in the embodiments of the present application.

[0164] It should be understood that the present application is not limited to the particular configurations and processes described and illustrated herein. Detailed descriptions of known methods are omitted for the sake of brevity. In the above embodiments, several specific steps are described and illustrated as examples. However, the method processes of the present application are not limited to the specific steps described and illustrated, and those skilled in the art can make various changes, modifications and additions, or change the order of the steps, after understanding the spirit of the present application.

[0165] The functions noted in the description of the structural block diagrams above can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, functional cards, and the like. When implemented in software, the elements of the present application are program or code segments that are used to perform the required tasks. The program or code segments can be stored in a machine-readable medium or transmitted through a data signal carried in a carrier wave over a transmission medium or communication link. A "machine-readable medium" includes any medium that can store or transport information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, and the like. The code segments can be downloaded via computer networks such as the Internet, intranets, and the like.

[0166] It is also important to note that the examples described herein can be implemented in a variety of systems, including and / or incorporating software, firmware, hardware, and / or circuitry. Also, the present application can be implemented as a system-on-chip (SOC) where each block of the described architecture is implemented in a single chip. Further, it is important to note that, as used herein, the term "exemplary" is intended to be exemplary only and is not intended to indicate that a described embodiment is preferred over other embodiments. Also, the term "comprising" is intended to be inclusive of the described elements and / or steps, but not exclusive of other elements and / or steps. Further, the term "coupled" is intended to be inclusive of a direct connection between two elements or a connection through one or more intermediate elements.

[0167] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. Alternatively, computer program implemented steps can be implemented by one or more of the components of the system with the processor controlling the system's operation. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0168] The above merely describes specific implementation of the present application, and those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, module and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described herein again. It should be understood that the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A longitudinal vehicle speed drive control method, characterized in that, The method includes: Obtain the vehicle's target speed, preset acceleration, and the vehicle's current first speed; Based on the target vehicle speed, the preset acceleration, and the first speed, the acceleration time for the vehicle to accelerate from the first speed to the target vehicle speed is obtained; Based on the acceleration time, calculate the second speed of the vehicle at each time step within the acceleration time, and the first acceleration of the vehicle at each adjacent two time steps; Based on the first acceleration and a pre-set first correspondence between the vehicle's acceleration and torque, a first torque corresponding to the first acceleration is obtained; For each time step, based on the second speed, the first speed of the vehicle at the time step, and the first torque, a target torque of the vehicle at the time step is determined, wherein the target torque is used to drive the vehicle. Before obtaining the first torque corresponding to the first acceleration based on the first acceleration and a pre-set first correspondence between vehicle acceleration and torque, the method further includes: Obtain the relationship between the angular velocity, moment of inertia, electromagnetic torque, and damping torque of the motor; wherein the moment of inertia and the damping torque in the relationship are constant values; Acquire multiple sets of historical experimental data; each set of historical experimental data includes historical electromagnetic torque and historical angular velocity; Substituting the historical electromagnetic torque and historical angular velocity from each set of historical experimental data into the relational formula, we obtain the first coefficient of the electromagnetic torque and the second coefficient of the angular velocity in the relational formula. Based on the first coefficient and the second coefficient, a third correspondence between the angular velocity and the electromagnetic torque is obtained; By replacing the vehicle's acceleration with the angular velocity, the first correspondence between the vehicle's acceleration and torque is obtained.

2. The method according to claim 1, characterized in that, Determining the target torque of the vehicle at the time step based on the second speed, the vehicle's first speed at the time step, and the first torque includes: Based on the second speed and the first speed of the vehicle at the time step, the second torque of the vehicle at the time step is determined; Based on the first torque and the second torque, the target torque of the vehicle at the time step is determined.

3. The method according to claim 2, characterized in that, Determining the target torque of the vehicle at the time step based on the first torque and the second torque includes: The first torque and the second torque are superimposed to obtain the third torque; The third torque is determined as the target torque of the vehicle at the time step.

4. The method according to claim 2, characterized in that, Determining the second torque of the vehicle at the time step based on the second speed and the first speed of the vehicle at the time step includes: Calculate the target speed deviation between the second speed and the first speed of the vehicle at the time step; Based on the target speed deviation and the pre-set second correspondence between speed deviation and torque, the second torque corresponding to the target speed deviation at the time step is determined.

5. The method according to claim 1, characterized in that, The step of replacing the vehicle's acceleration with the angular velocity to obtain the first correspondence between the vehicle's acceleration and torque includes: When the vehicle's driving state meets the preset driving state, the vehicle's acceleration is replaced with the angular velocity to obtain the first correspondence between the vehicle's acceleration and torque.

6. The method according to claim 1, characterized in that, The relationship between the angular velocity, moment of inertia, electromagnetic torque, and damping torque of the motor is shown in the following formula: in, The angular velocity of the motor rotation; The moment of inertia is the rotational inertia; The electromagnetic torque; The damping torque is denoted as .

7. A longitudinal vehicle speed drive control device, characterized in that, The device includes: The acquisition module is used to acquire the vehicle's target speed, preset acceleration, and the vehicle's current first speed; The first determining module is used to determine the acceleration time of the vehicle from the first speed to the target speed based on the target vehicle speed, the preset acceleration, and the first speed. The first calculation module is used to calculate, based on the acceleration time, the second speed of the vehicle at each time step within the acceleration time, and the first acceleration of the vehicle at each adjacent two time steps; The second determining module is used to obtain a first torque corresponding to the first acceleration based on the first acceleration and a pre-set first correspondence between the vehicle's acceleration and torque. The third determining module is used to determine the target torque of the vehicle at each time step based on the second speed and the first speed of the vehicle at the time step, wherein the target torque is used to drive and control the vehicle to drive. The acquisition module is further configured to: before obtaining the first torque corresponding to the first acceleration based on the first acceleration and a pre-set first correspondence between the vehicle's acceleration and torque, acquire the relationship between the motor's angular velocity, moment of inertia, electromagnetic torque, and damping torque; wherein the moment of inertia and the damping torque in the relationship are constant values; acquire multiple sets of historical experimental data; wherein each set of historical experimental data includes historical electromagnetic torque and historical angular velocity; The fourth determining module is used to substitute the historical electromagnetic torque and the historical angular velocity from each set of historical experimental data into the relational formula to obtain the first coefficient of the electromagnetic torque and the second coefficient of the angular velocity in the relational formula; based on the first coefficient and the second coefficient, a third correspondence between the angular velocity and the electromagnetic torque is obtained; and the vehicle acceleration is replaced with the angular velocity to obtain the first correspondence between the vehicle acceleration and the torque.

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