Study on the automated control of a motor vehicle in a test cycle on the chassis dynamometer

Abstract

The automatic operation of the pedals of a motor vehicle represents a first stage of the transition from driving without assistance to rolling in completely autonomous mode. This paper presents the construction of an autonomous control system that actuates the acceleration and braking pedals for a passenger car equipped with an automatic transmission. The system allows the completely autonomous rolling of the vehicle on the chassis dynamometer. This type of control has many advantages such as ensuring a good repeatability of the tests performed or improving the safety in the workplace by reducing human involvement. For this type of automation, a PID controller is used, with the input data being the speed required by the WLTC test cycle. The output data is represented by the position of the actuating elements and the feedback of the system is provided by the actual speed of the motor vehicle. In order to determine the actual speed of the motor vehicle, an incremental optical encoder is mounted to the wheel of the vehicle. The position of the acceleration and braking pedals is determined by the position transducers of the actuating elements. The development of the hardware continues with the design of the assembly that supports the two actuators as well as the parts that allow the connection between the pedals and the execution elements. The actual mechanical stress of the hardware is determined using a finite elements analysis, which requires a 3D model of the automated system components. The stability analysis is performed by checking the tilt of the device and the relative slip between the device and the vehicle floor. For control software design, the Arduino programming environment was chosen, being able to perform the automated control between the input and the output data of the drive system with good accuracy and calculation speed.