CN-121999673-A - New forms of energy electric car experiment teaching device

CN121999673ACN 121999673 ACN121999673 ACN 121999673ACN-121999673-A

Abstract

The invention discloses an intelligent new energy electric car experiment teaching device, and belongs to the technical field of new energy automobile teaching equipment. Aiming at the problems of high cost, invisible internal structure, high-voltage potential safety hazard, theoretical and practical disjointing and the like of the traditional intelligent automobile teaching equipment, a solution which fuses a modularized transparent chassis and a digital twin technology is provided. The device comprises a physical teaching platform and a digital prototype measurement and control system based on ROS/Gazebo. The physical platform adopts a metal chassis with a transparentization design, integrates a disconnected front axle and an integral rear axle, and the rear axle is provided with a motor driving and speed measuring device. The steering system realizes smooth switching between manual and automatic modes through a torque sensor and an electromagnetic combined sleeve mechanism. The digital prototype constructs a high-precision simulation model through URDF files, and virtual-real linkage is realized by using real-time sensor data driving. The invention obviously improves the safety, intuitiveness and interactivity of teaching.

Inventors

LEI GANG
Liu Yechen
GAO ANG
Zhang Lingxun
WANG ZHONGLIN
BO JIAJUN
ZHANG RONG
CHU ZHIGANG

Assignees

重庆大学

Dates

Publication Date: 20260508
Application Date: 20260129

Claims (7)

1. The new energy electric car experiment teaching device is characterized by comprising a physical experiment teaching device, namely a physical prototype, a digital prototype test control system, namely a digital prototype, wherein the physical prototype comprises a car body chassis, a front wheel suspension, a rear wheel suspension, a driving device and a steering system, and the steering system is a power steering device with an automatic and manual switching function; The digital prototype is operated on a computer terminal and comprises a digital twin model, a data acquisition module and a virtual-real interaction control module, wherein the digital twin model is a kinematic and dynamic simulation model established based on a three-dimensional model of a physical experiment teaching device; The digital prototype is a digital twin model driven by a Matlab/Simulink control strategy and sensor data of the physical prototype obtained in real time through a data acquisition module, can move according to the Matlab/Simulink control strategy, and can perform feedback adjustment according to real movement conditions acquired by the physical prototype.
2. The new energy electric car experiment teaching device according to claim 1, wherein the steering system comprises a steering wheel (32), a steering column (34), a torque sensor (33), a first straight gear (22), a second straight gear (23), a third straight gear (24), a steering rod (25), a steering engine (18), a fourth straight gear (19), a combination sleeve (20) with a movable iron core, an electromagnetic coil spring (21), a steering pull rod (7), a return spring (8), a steering gear (14), a steering straight rack (15) and a straight rack limit position stop (16), the steering wheel (32) and the steering column (34) are fixedly connected through the torque sensor (33), the torque sensor (33) can measure the torque transmitted to the steering column (34) by the steering wheel (32), the steering column (34) is fixedly connected with the first straight gear (22), the first straight gear (22) is disconnected with the second straight gear (23) along the axial direction without direct contact, the second straight gear (23) is fixedly connected with the steering rod (25), the third straight gear (24) is a stepped gear (24) with the radius of the upper straight gear (25) and the radius of the third straight gear is larger than the radius of the first straight gear (24), the third straight gear (24) can rotate circumferentially relative to the steering rod (25); the fourth straight gear (19) is fixed on an output shaft of the steering engine (18), the fourth straight gear (19) is meshed with a pinion of the third straight gear (24), the first straight gear (22), the second straight gear (23) and the large gear of the third straight gear (24) are consistent in parameters, the tooth form of the combining sleeve (20) with the movable iron core can be meshed with the large gears of the first straight gear (22), the second straight gear (23) and the third straight gear (24), when the electromagnetic coil is powered off, the large gears of the second straight gear (23) and the third straight gear (24) are locked in the circumferential direction through the combining sleeve (20) with the movable iron core, when the electromagnetic coil is powered on, the large gears of the first straight gear (22) and the second straight gear (23) are locked in the circumferential direction through the combining sleeve (20) with the movable iron core, the combining sleeve has the function of moving up and down to switch the meshing state, the steering gear (14) is connected with the large gears (14) under the steering rod (25), when the electromagnetic coil is powered off, the large gears (14) and the steering gear (15) and the steering rack (15) is driven to move in the left and right through the steering rack (15) to rotate.
3. The new energy electric car experiment teaching device according to claim 2 is characterized in that when the electromagnetic coil is powered off, the combined sleeve (20) with the movable iron core is in a lower position under the action of gravity or a reset spring, so that the combined sleeve (20) with the movable iron core is simultaneously meshed with the large gears of the second straight gear (23) and the third straight gear (24), and at the moment, the power of the steering engine is transmitted to the steering rod (25) through the fourth straight gear (19), the small gear of the third straight gear (24), the large gear of the third straight gear (24), the combined sleeve (20) with the movable iron core and the second straight gear (23), so that automatic auxiliary driving steering is realized; When the torque sensor (33) detects that the torque of the steering wheel is larger than a preset threshold value of 5 N.m, the singlechip controls the electromagnetic coil to be electrified, and the combined sleeve (20) with the movable iron core is attracted to move upwards, so that the combined sleeve is meshed with the first straight gear (22) and the second straight gear (23) and is separated from the large gear of the third straight gear (24), and at the moment, the torque of the steering wheel is directly transmitted to the steering rod (25) through the torque sensor (33), the steering column (34), the first straight gear (22), the combined sleeve (20) with the movable iron core and the second straight gear (23), so that manual steering is realized.
4. The new energy electric car experiment teaching device according to claim 3, wherein the system is in an auxiliary driving mode by default, namely, a coil is powered off, when a student rotates a steering wheel, a comparator judges whether torque is larger than 5 N.m after the change of a voltage signal output by a torque sensor is sampled by an ADC, if so, a high level is output to a relay, so that an electromagnet is attracted, a combining sleeve moves upwards, and the system enters a mechanical take-over mode.
5. The new energy electric car experiment teaching device according to claim 1, wherein the construction and operation method of the digital prototype measurement and control system comprises the following steps: (1) Step S1, a three-dimensional model of a physical device is established by utilizing three-dimensional modeling software, and parts are split into independent connecting rods Link according to motion logic; (2) S2, converting the three-dimensional model into URDF format description files, defining the mass attribute and the moment of inertia of the connecting rod, and configuring the type, the limit position and the damping coefficient of the Joint; (3) Step S3, loading the URDF file in Gazebo simulation environment of the ROS operating system to generate a digital twin model consistent with the geometric and kinematic characteristics of the physical device; (4) Establishing a multidimensional communication link between a control model and a digital prototype, between the control model and a physical prototype and between the physical prototype and the digital prototype; (5) The control strategy model is connected with the physical prototype by adopting STLINK V2.1.1 downloader, and a virtual serial port is newly added to realize direct connection with the STM32F407 controller of the lower computer.
6. The new energy electric car experiment teaching device according to claim 5, wherein the specific implementation method of the communication link is as follows: (1) The method comprises the steps of constructing a system overall control strategy by adopting numerical calculation software, configuring the numerical calculation software as an ROS client node through a local area network communication protocol, and connecting the ROS client node to a Master node Master of an ROS system to realize the sending and receiving of control instructions, wherein the specific implementation process is as follows: 1) Setting up a system overall control strategy by Matlab/Simulink; 2) Roscore, starting a node manager instruction in the ROS system, and inquiring the IP of the virtual machine in the ROS new terminal through an ifconfig instruction; 3) Specifying the location of the ROS Master node Master in the Matlab command window, instruction setenv ('ROS_MASTER_URI', 'http:// 192.168.0.117:11311/'); 4) Initializing a ROS client node of Matlab, and executing instructions rosinit; (2) The control model is communicated with the physical prototype, namely, a STLINK v 2.1.1 downloader is adopted for connection, and a virtual serial port is newly added to realize direct connection with a lower computer STM32F407 controller; The physical prototype is communicated with the digital prototype, wherein bottom sensor data of the physical prototype is collected through STM32F407, sent in a WIFI form through an ESP32 development board, and received in a WIFI form through the ESP32 development board at the digital prototype end; the real state of the physical prototype is transmitted to the digital prototype through the speed position sensor, the difference between the digital prototype and the physical prototype is subjected to feedback correction, and the digital prototype can display control model parameters, physical prototype parameters and actual parameters of the current virtual prototype in real time.
7. The new energy electric car experimental teaching device according to claim 1, characterized in that the rear wheel suspension adopts an integral structure, the driving device (1) is arranged at the middle position of the rear axle, and the driving device comprises a motor (27), a speed reducer formed by a fifth gear (26) and a sixth gear (28), and a differential formed by a seventh gear (29) and an eighth gear (30): The rear axle cylinder type shock absorber (2), the rear axle shell (3), the frame (5) and the support rod (4) form a triangular connecting rod mechanism to limit longitudinal displacement; The rear axle cylinder type shock absorber (2) is adhered with a strain gauge on the surface of the shock absorber and is used for measuring suspension dynamic load caused by road surface excitation, a motor (27) drives a fifth gear (26) to rotate, the fifth gear (26) is meshed with a sixth gear (28) to form a speed reducer, a fifth connecting rod (31) is fixedly connected to the inner side of the sixth gear (28), an eighth gear (30) is installed near the center of the fifth connecting rod (31), the eighth gear (30) can rotate relative to the fifth connecting rod (31), a seventh gear (29) of two side half shafts is meshed with the eighth gear (30), the eighth gear (30) is a sun gear of the differential, the sun gear can rotate around the axis of the fifth connecting rod (31) or revolve along with the rotation of the sixth gear (28), and the revolution angular speed of the eighth gear (30) is equal to the rotation angular speed of the sixth gear (28).

Description

New forms of energy electric car experiment teaching device Technical Field The invention belongs to the technical field of new energy automobile teaching equipment, and particularly relates to a new energy electric car experiment teaching device. Background In the field of new energy automobile teaching, existing experimental equipment is often reformed based on a traditional fuel automobile or directly used for producing new energy automobile types in a large scale as a teaching tool. Such devices have the following limitations in general: 1. the cost is high, and the initial investment and the maintenance cost of the new energy automobile are high. In addition, since the vehicle is updated quickly, the equipment may be out of date quickly and the continuous upgrade cost is not affordable. 2. The internal structure is invisible, namely, in order to ensure the strength and the attractive appearance, a mass production vehicle is generally designed in a closed mode, students are difficult to visually observe the working state and the connection mode of internal components, and a large gap exists between theoretical knowledge and actual operation. 3. High-voltage potential safety hazard that potential safety hazard exists in a high-voltage battery and a motor system of a new energy automobile, particularly in a teaching environment, students lack necessary professional training, and safety accidents are easily caused by direct contact with high-voltage components. 4. The theory and practice are disjointed, that is, the existing teaching equipment is often focused on static display or single linear teaching, lacks deep fusion with a modern vehicle control strategy, and is difficult for students to master key technologies and control strategies of new energy automobiles in practice. 5. The traditional teaching equipment can only demonstrate specific teaching contents, such as vehicle construction or simple dynamics, can not support simulation and experiment under complex working conditions, and limits the breadth and depth of the experiment. 6. The traditional digital twin experiment teaching equipment can only drive the movement of the digital prototype according to the measurement data of the physical prototype, the teaching equipment can not only control the physical prototype by using the control strategy model, but also drive the physical prototype by using the control strategy model, and the difference between the theoretical value of the digital prototype and the actual value of the physical prototype can be actually displayed in the digital prototype through the feedback of the measurement data of the physical prototype to the digital prototype. The problems seriously affect the teaching quality of the related courses of the new energy automobile and the learning experience of students. Therefore, development of a novel experimental teaching device is needed, which has the characteristics of high cost effectiveness, strong structural visibility, perfect safety protection measures, high verification capability of virtual-real combined control strategies and high experimental flexibility, so as to overcome the limitations of the traditional teaching equipment and promote the modernization process of new energy automobile education. Through retrieval, application publication number CN213275888, a new energy automobile three-electric system comprehensive experiment system comprises a rack, a driving assembly, a loading assembly, wheels and a measurement and control system, wherein the driving assembly comprises a test motor, a first gear box and a driving box, a torsion sensor is arranged between the test motor and the first gear box, the driving box is connected with the driving box, the driving box is connected with two wheels, the loading assembly comprises a loading motor and two friction rollers, the loading motor is connected with the two friction rollers and then can drive the two friction rollers to rotate, the two friction rollers are respectively arranged under the two wheels correspondingly and are attached to the corresponding wheels, and the test motor, the torsion sensor and the loading motor are all connected with the measurement and control system. The platform can complete performance test experiments of the power motor under various working conditions of the new energy automobile, has a simple overall structure and low cost, and is suitable for teaching of universities, teaching institutions and the like. The comparative patent focuses mainly on the simplified design of the physical test platform, but fails to solve the core problems of the teaching equipment in the aspects of visualization, safety, interactivity and cost. The invention realizes the improvement of the safety, intuitiveness, interactivity and economy of teaching equipment by innovatively fusing the modularized transparent chassis and the digital twin technology, and breaks through the limitation of the traditional technolog