A bus slow brake simulation system and method

Abstract

The application discloses a bus slow braking simulation system and method, which comprises a parameter input module, a simulation calculation module and a data recording and visualization module. The scene parameters and simulation parameters are input by technical personnel through the parameter input module. The slow braking strategy is obtained through slow braking simulation based on the scene parameters and simulation parameters by the simulation calculation module. The data recording and visualization module is used for data recording and visual display of the slow braking simulation results. The bus slow braking simulation system provided by the application can be used by bus auxiliary driving researchers, and is used for simulating the slow braking strategy of the collision relief braking scene. According to the initial distance, the expected safe braking time and other scene parameters, different slow braking strategies can be simulated based on different simulation parameters. The different slow braking strategies provided by simulation can be used for the training data of the bus auxiliary driving artificial intelligence model through intuitive display for comparison by technical personnel.

Description

Technical Field

[0001] This application provides a bus drivability braking simulation system and method, which relates to the field of bus assisted driving technology. Background Technology

[0002] Collision mitigation braking system is a safety technology system used to assist driving, predict collisions, and actively prevent them. It uses microwave radar and / or a monocular camera to sense and identify vehicles ahead, oncoming vehicles, and pedestrians. When a collision hazard with a vehicle or pedestrian is possible, the system alerts the driver to take evasive action through warning sounds and instrument panel displays. As the vehicle gets closer to the vehicle or pedestrian ahead, the system applies slight braking to provide a tactile reminder to the driver to take control of the vehicle. When the vehicle gets even closer, the system applies strong braking to assist the driver in avoiding a collision and reducing injury.

[0003] Applying driver assistance systems to buses, a special type of vehicle, requires addressing specific scenario-related issues. For example, collision mitigation braking systems need to achieve both active braking and gentle braking, because when a bus brakes, both external and internal safety must be considered. Since most passengers on a bus are not wearing seatbelts or are standing, bus braking needs to achieve a gentle braking effect.

[0004] How to conduct gentle braking simulation for bus braking scenarios has become a pressing technical problem that needs to be solved in this field. Summary of the Invention

[0005] The technical problem this application aims to solve is how to perform slow braking simulation for bus braking scenarios.

[0006] To address the aforementioned technical problems, this application provides a bus easing braking simulation system, comprising a parameter input module, a simulation calculation module, and a data recording and visualization module. The parameter input module allows technicians to input scenario parameters and simulation parameters. The simulation calculation module performs easing braking simulation based on the scenario parameters and simulation parameters to obtain an easing braking strategy. The data recording and visualization module is used to record and visualize the easing braking simulation results.

[0007] Preferably, the scene parameters include:

[0008] Initial distance L, the initial distance between the vehicle and the obstacle;

[0009] Initial velocity V0, the initial velocity of the vehicle;

[0010] Expected braking time TE, expected safe braking time;

[0011] The reference acceleration *as* is the reference value for braking deceleration.

[0012] Preferably, the simulation parameters include:

[0013] PID parameters, including proportional, integral, and derivative coefficients;

[0014] Simulation time TS, the total simulation time.

[0015] Preferably, the simulation calculation module simulates the vehicle braking process, advancing the simulation time simulation cycle with a fixed time step dt, specifically including the following steps:

[0016] S1 calculates the desired speed Ve. The maximum permissible safe speed is calculated based on the remaining distance Dt and the safe distance S, which is the desired speed. The calculation formula is: Ve=(Dt-S) / TE;

[0017] S2 PID control intervenes. When the vehicle speed Vt exceeds the desired speed Ve, PID control is activated to adjust the braking coefficient. The PID calculates the braking coefficient by using the error et between the vehicle speed Vt and the desired speed Ve as the input of the PID control. The output Fc is limited to the range [0,1].

[0018] S3 updates the physics model:

[0019] The remaining distance decreases, Dt = Dt - Vt*dt;

[0020] As the vehicle speed decreases, Vt = Vt - at * dt;

[0021] The desired braking time is reduced, TE = TE - dt;

[0022] S4 Termination Condition:

[0023] Termination condition 1: The loop ends when the vehicle speed Vt is lower than the set threshold.

[0024] Termination condition 2: The loop ends when the remaining distance Dt is less than the safe distance S;

[0025] The loop ends if either termination condition one or termination condition two is satisfied.

[0026] Preferably, the data recording and visualization module is used to store the data changes of all variables and display them through visualization.

[0027] Furthermore, the data recording and visualization module includes a log submodule, which is used to record vehicle speed, braking coefficient, speed error, and remaining distance data at each time step.

[0028] Furthermore, the data recording and visualization module includes a chart visualization display submodule, which includes a braking coefficient-time chart display; a vehicle speed-time chart display; a remaining distance-time chart display; and a PID parameter-time chart display.

[0029] This application also provides a method for simulating the slow braking of a bus, which uses the aforementioned bus slow braking simulation system to simulate the slow braking of a bus.

[0030] This application also provides an electronic device, including: a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program to implement the aforementioned bus easing braking simulation method.

[0031] This application also provides a computer-readable storage medium for storing a computer program that, when executed, implements the aforementioned bus easing braking simulation method.

[0032] The bus easing braking simulation system provided in this application can be used by bus assisted driving R&D personnel to simulate easing braking strategies in collision mitigation braking scenarios. Based on scenario parameters such as initial distance and expected safe braking time, different easing braking strategies can be simulated based on different simulation parameters. The simulation provides a visual demonstration for technical personnel to compare. The different easing braking strategies provided by the simulation can also be used as training data for bus assisted driving artificial intelligence models. Attached Figure Description

[0033] Figure 1 This is a diagram illustrating the architecture of a bus braking simulation system provided in an embodiment of this application.

[0034] Figure 2 This is a schematic diagram simulating the vehicle braking process for the simulation calculation module. Detailed Implementation

[0035] To make this application more apparent and understandable, various exemplary embodiments will be described below. These examples are non-limiting and should be understood as illustrating aspects of the broader application of the apparatus, system, and method. These embodiments can be varied and substituted with equivalents without departing from the spirit and scope of this application. Furthermore, various variations can be made to adapt to specific circumstances, materials, material compositions, processing types, processing actions, or steps to suit the purpose, content, or scope of this application. All such variations will be within the protection scope of this application.

[0036] Any materials, dimensions, or quantities described in the overview or detailed description are merely examples and are not intended to limit the subject matter of this application. Furthermore, the various implementations of the embodiments described herein are complementary rather than purely alternating, unless otherwise stated. In other words, implementations from one embodiment can be freely combined with implementations from other embodiments, as will readily be apparent to those skilled in the art, unless these implementations are stated to be used only as substitutions.

[0037] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] Example

[0040] The bus easing braking simulation system provided in this application embodiment is used by bus assisted driving R&D personnel to simulate easing braking strategies in collision mitigation braking scenarios. Based on scenario parameters such as initial distance and expected safe braking time, different easing braking strategies can be simulated based on different simulation parameters, which can be intuitively compared by R&D personnel. The different easing braking strategies provided by the simulation can also be used as training data for bus assisted driving artificial intelligence models.

[0041] In one embodiment, the bus easing braking simulation system provided in this application is described in [reference needed]. Figure 1 It includes a parameter input module, a simulation calculation module, and a data recording and visualization module; the parameter input module is used by technicians to input scene parameters and simulation parameters; the simulation calculation module performs easing braking simulation based on the scene parameters and simulation parameters to obtain the easing braking strategy; the data recording and visualization module is used to record and visualize the easing braking simulation results.

[0042] The simulation module simulates the vehicle braking process, converting braking time into a safe speed target. It uses PID closed-loop control to adjust the braking coefficient in real time, ensuring the vehicle stops within a set time and maintains a safe distance. The physical model depicts the vehicle deceleration process, where the braking coefficient affects deceleration, which in turn affects speed and distance changes. The simulation module adjusts the braking force based on the error between the vehicle speed and the desired speed, stabilizing the system to the desired state as quickly as possible. The data recording and visualization module integrates multi-dimensional visualization, simultaneously plotting the braking coefficient, speed, distance, and PID component curves, intuitively displaying and analyzing the control process. Visualization addresses issues encountered when adjusting PID parameters, such as oscillations, slow convergence, or unexpected braking distances. It also verifies the correctness of the control logic, the rationality of error calculation, the correct accumulation of the integral term, and whether the rate of change of the derivative term has been handled.

[0043] In a further implementation,

[0044] The scene parameters include:

[0045] Initial distance L, the initial distance between the vehicle and the obstacle;

[0046] Initial velocity V0, the initial velocity of the vehicle;

[0047] Expected braking time TE, expected safe braking time;

[0048] The reference acceleration *as* is the reference value for braking deceleration.

[0049] The simulation parameters include:

[0050] PID parameters, including proportional, integral, and derivative coefficients;

[0051] Simulation time TS, the total simulation time.

[0052] In a further implementation, the simulation module simulates the vehicle braking process, advancing the simulation time cycle with a fixed time step dt, see [link to relevant documentation]. Figure 2 Specifically, it includes the following steps:

[0053] S1 calculates the desired speed Ve. The maximum permissible safe speed is calculated based on the remaining distance Dt and the safe distance S (1.5 meters), which is the desired speed. The calculation formula is: Ve = (Dt - S) / TE.

[0054] When S2 PID control intervenes, if the vehicle speed Vt (initially V0) exceeds the desired speed Ve, PID control is activated to adjust the braking coefficient. The PID calculates the braking coefficient by using the error et between the vehicle speed Vt and the desired speed Ve as the input of the PID control. The output Fc is limited to the range [0,1].

[0055] For example, in the embodiments of this application, the calculation formula for PID control is Fc=Kp*et+Ki*∑et*dt+Kd*det / dt, where Kp, Ki and Kd are the proportional, integral and derivative coefficients, respectively, which together constitute the PID parameters. These parameters are set by technicians before simulation, and different simulation results can be obtained by using different PID parameters.

[0056] It is understandable that the actual braking deceleration at = Fc * as, the reference acceleration as is related to the specific vehicle braking system, and can be understood as the maximum braking deceleration that the vehicle braking system can produce. The braking coefficient Fc is used to measure the actual working state of the braking system, such as the braking force, and at = Fc * as is the actual braking deceleration produced by the braking system.

[0057] S3 updates the physics model:

[0058] The remaining distance decreases, Dt = Dt - Vt*dt;

[0059] As the vehicle speed decreases, Vt = Vt - at * dt;

[0060] The desired braking time is reduced, TE = TE - dt;

[0061] Therefore, the larger the braking coefficient, the greater the deceleration, and the faster the vehicle stops.

[0062] S4 Termination Condition:

[0063] Termination condition 1: The loop ends when the vehicle speed Vt is lower than the set threshold (set to a small value), which is considered that the vehicle has stopped, to avoid unrealistic situations such as negative speed;

[0064] Termination condition two: The loop ends when the remaining distance Dt is less than the safe distance S, which is considered a failure of vehicle braking;

[0065] The loop ends if either termination condition one or termination condition two is satisfied.

[0066] The simulation module provided in this application simulates the vehicle braking process through a cyclic simulation with a fixed time step dt. During the simulation, PID feedback control is used to keep the vehicle speed close to the desired speed, avoiding forceful braking and smoothing the braking curve. The overall idea is to mimic the braking process of a person. After detecting an obstacle, the brake pedal is first applied lightly, and as the distance decreases and the speed decreases, the brake is gradually applied deeper. When the distance and speed decrease to a safe level, the brake is slowly released to reduce the braking force. At the end of the braking process, the vehicle speed gradually decreases, achieving a gentle braking effect.

[0067] Understandably, the desired speed is affected by the set desired braking time. When using the bus descent braking simulation system, technicians can adjust the descent braking simulation by setting different desired braking times, thereby observing the descent braking simulation results under different desired braking times.

[0068] In a further implementation, the data recording and visualization module is used to store the data changes of all variables and to display them visually, specifically including:

[0069] The log submodule is used to record detailed data such as vehicle speed, braking coefficient, speed error, remaining distance, and PID parameters for each time step.

[0070] The chart visualization submodule includes a braking coefficient-time chart display, reflecting the dynamic adjustment of braking force; a vehicle speed-time chart display, showing the process of vehicle speed decreasing; a remaining distance-time chart display, showing the change in distance between the vehicle and obstacles; and a PID parameter-time chart display, representing the contributions of P, I, and D components respectively.

[0071] The bus easing braking simulation system provided in this application allows technicians to simulate easing braking strategies for collision mitigation scenarios by setting simulation parameters and initial scenario parameters. Technicians can adjust various parameters such as initial distance, initial speed, expected safe braking time, baseline acceleration, and PID parameters to obtain different easing braking strategies according to simulation requirements. The bus easing braking simulation system provided in this application offers intuitive graphical displays for developers to visually compare data. Detailed data stored in the log submodule can also be used as training data for the bus assisted driving artificial intelligence model.

[0072] This application also provides a method for simulating the slow braking of a bus, which uses the aforementioned bus slow braking simulation system to simulate the slow braking of a bus.

[0073] It is understood that the implementation of the bus easing braking simulation system provided in this application relies on a computer program to allocate or instruct corresponding hardware such as storage devices, processors, and displays. After reading and understanding all or part of the processes executed by the bus easing braking simulation system provided in this application, those skilled in the art can easily implement it through a computer program. There are no technical obstacles for those skilled in the art, and no creative effort is required.

[0074] This application also provides a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. The processor of an electronic device reads the computer instructions from the computer-readable storage medium, and when the processor executes the computer instructions, it implements the bus easing braking simulation system and bus easing braking simulation method provided in this application.

[0075] This application also provides an electronic device, specifically including: a processor and a memory, wherein the memory is used to store a computer program, the computer program is loaded and executed by the processor to implement a bus easing braking simulation system and a bus easing braking simulation method.

[0076] The above description is merely a preferred embodiment of this application and does not constitute any limitation on this application in any form or substance. It should be noted that those skilled in the art can make several improvements and additions without departing from this application, and these improvements and additions should also be considered within the scope of protection of this application. Any modifications, alterations, and equivalent variations made by those skilled in the art based on the disclosed technical content without departing from the content and scope of this application are equivalent embodiments of this application. Furthermore, any equivalent changes, alterations, and variations made to the above embodiments based on the essential technology of this application still fall within the scope of the technical solution of this application.

Claims

1. A bus drowsy braking simulation system, characterized in that, It includes a parameter input module, a simulation calculation module, and a data recording and visualization module; the parameter input module allows technicians to input scene parameters and simulation parameters; the simulation calculation module performs a descent braking simulation based on the scene parameters and simulation parameters to obtain a descent braking strategy; the data recording and visualization module is used to record and visualize the descent braking simulation results. The scene parameters include: The initial distance L is the initial distance between the vehicle and the obstacle; The initial velocity V0 is the initial velocity of the vehicle. Expected braking time TE, i.e., the expected safe braking time; The reference acceleration as is the reference value for braking deceleration. The simulation parameters include: PID parameters, including proportional, integral, and derivative coefficients; Simulation time TS, i.e., the total simulation time; The simulation module simulates the vehicle braking process, advancing the simulation time cycle with a fixed time step dt, specifically including the following steps: S1 calculates the desired speed Ve. The maximum permissible safe speed is calculated based on the remaining distance Dt and the safe distance S, which is the desired speed. The calculation formula is: Ve = (Dt-S) / TE; S2 PID control intervenes. When the vehicle speed Vt exceeds the desired speed Ve, PID control is activated to adjust the braking coefficient. The PID calculates the braking coefficient by using the error et between the vehicle speed Vt and the desired speed Ve as the input of the PID control. The output Fc is limited to the range [0,1]. S3 Update Physics Model: The remaining distance decreases, Dt = Dt - Vt*dt; As the vehicle speed decreases, Vt = Vt - at * dt; The desired braking time is reduced, TE = TE - dt; S4 Termination Condition: Termination condition 1: The loop ends when the vehicle speed Vt is lower than the set threshold. Termination condition 2: The loop ends when the remaining distance Dt is less than the safe distance S; The loop ends if either termination condition one or termination condition two is satisfied.

2. The bus easing braking simulation system according to claim 1, characterized in that, The data recording and visualization module is used to store the data changes of all variables and display them through visualization.

3. The bus easing braking simulation system according to claim 2, characterized in that, The data recording and visualization module includes a log submodule, which is used to record vehicle speed, braking coefficient, speed error, and remaining distance data at each time step.

4. The bus easing braking simulation system according to claim 2, characterized in that, The data recording and visualization module includes a chart visualization sub-module, which includes a braking coefficient-time chart display; a vehicle speed-time chart display; a remaining distance-time chart display; and a PID parameter-time chart display.

5. A method for simulating the gentle braking of a bus, characterized in that, The bus slow braking simulation system according to any one of claims 1-4 is used to simulate the slow braking of a bus.

6. An electronic device, characterized in that, include: Memory and processor; The memory is used to store computer programs; The processor is used to execute the computer program to implement the bus slow braking simulation method according to claim 5.

7. A computer-readable storage medium, characterized in that, Used to store a computer program, which, when executed, implements the bus easing braking simulation method of claim 5.

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