Design And Research Of The Key Components On The Autonomous Navigation Vehicle

In the early days, the central government raised that the fundamental way of the agriculture is mechanization of.A few years later, and now China’s agricultural mechanization has reached a very high level, China’s agricultural development is also to another period of major reform. The party’s 18 has proposed the development direction of China’s agriculture is scale operation,namely family farms, large grain, agricultural cooperatives and other forms of cultivation. Intelligent and refined quantitative requirements of agricultural machinery has been proposed by this development direction.Traditional aspects of the operation of agricultural machinery requires highly dependent on manual operations,Job quality and operational efficiency all rely on the experience of the driver to achieve.In this case,there is the low work efficiency, job quality is not guaranteed, a large driver’s labor intensity and other issues.Therefore, the development of autonomous navigation of agricultural machinery has a very important significance.This paper dedicated to the research of agricultural machinery automatic walking,used the signal monitoring technology, the SCM control technology, the mechanical drive technology and other technologies.In this present study,we put an electric car platform as the autonomous navigation walking platform,designed an automatic control system based on CAN bus.The system can accept commands sent by the onboard computer and control the running speed of the vehicle and the steering angle in accordance with directive.Eventually, the vehicle’s automatic walking function realized.This paper focuses on the research and the design producing of a vehicular automatic control system,The MCU is the core of the control system,and this system consists of three subsystems:the steering control system, speed control system and CAN bus communication system.(1)Steering control systems. This subsystem detects the current steering wheel angle by the steering angle sensor, the D/A converter converts the command voltage signal,when receiving steering commands coming onboard computer,The PID controller compares the two signals and calculates the voltage signal’s value that the steering motor drive required to achieve the steering control.(2)The vehicle speed control system.This subsystem detects the current vehicle speed by the encoder,the counter transmits the signal to the microcontroller in digital form.When the MCU received steering commands coming from onboard computer,the PID algorithm of Internal program compares the two signals and calculates the voltage signal value that the vehicle traveling motor driver needed, to achieve the vehicle speed control.(3)CAN bus communication system.This subsystem is mainly used for communication between the onboard computer and the other two control systems, which provides the expanding interface for the later system.In this paper,I made a lot of testing, tuned some system parameters, but also to verify the reliability and stability of the system,after the design, production, installation of the automatic control system were completed.