摘 要

本文根据巴哈赛车实际需求，利用电子产品开发系统Altium Designer和软件开发系统Keil等软件，经过电路设计、PCB设计以及软件设计，设计开发了一套用于巴哈赛车的驾驶数据采集系统，对巴哈赛车或其他专用场景的数据采集系统设计有一定的指导意义。

本系统创新性地采用了模块化、多传输手段等设计方案，且定义了车载通讯网络和无线通讯网络中标准的指令、数据结构，具有良好的开放性与可拓展性。

关键词：巴哈赛车；数据采集系统；模块化；多传输手段

Abstract

According to Baja racing car’s actual demand, with the use of electronic product development system Altium Designer and software development system Keil, through the circuit design, PCB design and software design, this paper design and develop a set of driving data acquisition system for Baja racing, which has certain guiding significance to Baja racing or other specialized data acquisition system design.

This system innovatively adopts the design scheme of modularization and multi-transmission means, and defines the standard instruction and data structure in the on-vehicle communication network and wireless communication network, which has good openness and extensibility.

Key words: Baja racing; data acquisition system; modularization; multi-transmission means

Contents

Chapter 1 Introduction 1

1.1 Purpose and significance 1

1.2 Research status at home and abroad 2

Chapter 2 System overview 4

Chapter 3 System hardware design 5

3.1 Hardware design of acquisition module 5

3.1.1 Overview 5

3.1.2 Design of analog signal acquisition circuit 5

3.1.3 Design of pulse signal acquisition circuit 8

3.1.4 Power circuit design 9

3.1.5 Design of master control unit and CAN transceiver 14

3.1.6 Connector design 16

3.1.7 PCB design 17

3.2 Storage module hardware design 18

3.2.1 Overview 18

3.2.2 Storage capacity calculation 19

3.2.3 Memory circuit design 19

3.2.4 Power circuit design 20

3.2.5 Master control unit and CAN transceiver 21

3.2.6 Connector design 21

3.2.7 PCB design 22

3.3 Hardware design of data transmission module 23

3.3.1 Overview 23

3.3.2 Power circuit design 24

3.3.3 Data transmission radio unit 24

3.3.4 4G network communication unit 25

3.3.5 Master control unit and CAN transceiver 26

3.3.6 Connector design 27

3.3.7 PCB design 28

Chapter 4 System software design 30

4.1 Instructions and data structures 30

4.1.1 On-vehicle communication network Instructions and data structures 30

4.1.2 Wireless communication network Instructions and data structures 30

4.2 Acquisition module master control unit program design 30

4.2.1 Overview 30

4.2.2 Initializer 31

4.2.3 Interrupts and interrupt service routines 35

4.3 Storage module master control unit program design 37

4.3.1 Overview 37

4.3.2 Initializer 38

4.3.3 File creation and data writing 38

4.4 Data transmission module master control unit program design 39

4.4.1 Overview 39

4.4.2 Initializer 40

4.4.3 Instruction and data forwarding 41

4.5 Cloud server 41

4.6 Remote devices program design 41

Chapter 5 Conclusion 43

Reference 44

Acknowledgement 46

Chapter 1 Introduction

• 1. Purpose and significance

This design aims to design a set of data acquisition system based on Baja racing car, which can realize driving data collection, transmission, storage and display.

Baja SAE China (BSC for short) is a cross-country vehicle design, manufacturing and testing competition organized by China society of automotive engineering and attended by undergraduate and vocational college students majoring in automobile and related majors. All participating team events in accordance with the rules and the car manufacturing standards, within the prescribed period of time, using the same type engine, designing and manufacturing a cross-country vehicle with single seat and MR layout, complete the static and dynamic projects competition. Static project includes technical examination, the car design, the manufacturing cost and the business marketing. And dynamic project includes the traction test, handling test, one-way of climbing test and 4 hours off-road endurance ^[1].

The BSC has been held since 2015, and the late start time has limited the research progress of each team on the racing electronic system. At present, the chassis adjustment of each team BSC car mostly depends on the driver's subjective feeling, but lacks objectivity and accuracy. In the car set-up and driver training, it needs all the data of the car for the vehicle calibration and race car driver training as data support. Therefore, developing a stable and reliable data collection system for Baja racing, collecting and analyzing the dynamic data of the system components, realizing the information feedback to the design optimization of the car, achieving the goal of optimization of vehicle parameters and vehicle test, in order to meet the demanding of events and improve performance, is very important to enhance the Baja racing performance and improve the level of the driver's operation ^[2].

Furthermore, the endurance event of the BSC racing dynamic program, which involve a variety of complex road conditions and harsh track conditions, puts forward higher requirements on the durability of each component system of the car. And endurance events allow the car to be repaired in case of damage. Only by evaluating the running status of each system of the racing car accurately and in real time and obtaining more accurate data related to the system parameters can the driver be reminded of the running status of a certain system, or help to accurately locate the fault location and save maintenance time when the vehicle fails.

Therefore, it is imperative to collect the driving data of Baja, which must be one of the researches focuses of Baja teams in the next few years.

• 1. Research status at home and abroad

At present, a large number of automobile and racing car parts manufacturers abroad have launched data acquisition system products. Among them, relatively civilian products such as Harry's Lap Timer, AIM solo, can be used to collect, store and display the driving data, track data and Lap speed data of racing cars with CAN, OBD, RS232, wi-fi and other means. They have low price, simple and convenient system, but have no direct sensor signal acquisition device, relies on the OBD interface, mobile phone or other intelligent devices, with limited functions and terminal, and remote data sharing cannot be realized.

Some companies have also introduced more specialized data collection systems, such as VBox data collection system of Racelogic, EDL, ADL series data logger and C series instrument with data collection function of MOTEC with T2 telemetry server and special data collection system of Formula, GP and other events provided by Marelli. These data acquisition device can provide analog and digital signal gathering, mass storage, multi-protocol signal input, multiple frequency wireless transmission, which has complete product ecological, can provide from the sensor acquisition, vehicle control, instrument display until the wireless transmission, software analysis software and hardware of the one-stop service. But the high prices and high requirements for hardware facilities make them rarely used by the team of low-level competition which has financial strain.

At present, at home and abroad, low-level racing cars such as FSC and CKC, mostly use self-made data acquisition system.Such as South China University of Technology, Hubei University of Automobile Technology, Qingdao University of Technology, Hubei University of Arts and Science, North University of China and South China Agriculture University, in the design of data acquisition system based on FSC racing, adopt STM32 as collection, master control chip, using CAN bus to transmit data, through the SD card storage, or by 433 MHZ, 2.4 GHz wireless module sends the data to the serial port receiver, using LabVIEW and Visual Basic to write the receiver program^[2-9].