Research On Measurement And Control System For Automotive Chassis Dynamometer Based On CAN-Bus

With the rapid development of technology,the structure of automotive is consummated gradually,and the requirement of automotive performance increases gradually too.Chassis dynamometer,testing equipment without disassembly,adopts technical of modern electrical measurement and computer to simulate all the driving resistance.So that the road test items can be tested indoor, and it will reduce the impact of outdoor environment.It can not only improve the testing environment but also increase the test precision.This dissertation gives the design of measurement and control system of chassis dynamometer which is based on CAN-bus.According to its function,the system is divided into the data collection node,the control node and the communication node.The communication between slave-computer and host-computer is realized by CAN-USB converter.The design based on CAN-Bus can make the duty definitely and beneficial to the extending and network of the hole system.Firstly,simply introduce the principle and structure of the automobile chassis dynamometer.On the basis of contrasting the resistance of the car driving on road and on the chassis dynamometer,it puts forward the electric simulation model.The advantage is that the flywheels are omitted,so it amplifies the structure of chassis dynamometer and realizes the continuous simulation of inertia.As to the design of hardware,the design methods and circuit diagrams are presented to detect the torque and rotation rate.The realization and design of excitation control system is also presented in detail,which is an important part of control system.For the control strategy of the system,double-closed-loop integral separation PID control is applied to increase the test precision.As to the design of software,the design idea and main flow charts are put forward.The portability and flexibility is increased by the modular programming of this software.Finally,it gives the electromagnetic compatibility design which further ensures the reliable operation of the system.