Wheeled mobile platform is a common structure of mobile robots and electric vehicles. If the wheels driven by individual motors can be accurately controlled, the mechanical construction will be simplified and the composed movement would be precise. The high accuracy tachometric control is based on precise measurement of each driving wheel’s speed. And the mobile platform introduced in this paper has simple structure with light weight and fast dynamic response. Therefore, the digital control cycle should not be long. When the wheels are traveling at a low speed and the sampling period is short, the measurement error would be great, using the traditional methods. We adopted multi-microprocessor and external circuit as the hardware, and chose equal precision method to measure the rotational speed. The results show that this system has achieved high accuracy measurement with errors within ±1‰, which would secure the latter precise control.

Rapid and high-accuracy guidance line identification and tracking are the keys to ensure AGV’s real-time control performance. Analyzing outdoor environment under different lighting conditions, we proposed a feature extraction method which could guarantee the efficiency and stability of line recognition for different surroundings; analyzing how angular deviation and distance deviation affect AGV posture, we designed a subdivision-control tracking strategy. The results show that the algorithm has achieved effective identification and tracking with an error less than ±5cm.