Design of Electromagnetic Navigation System for Inspection Robot
Aiming at the steering control accuracy problem of electromagnetic navigation inspection robot, a steering control strategy based on the sensor weighted data fusion is proposed. In order to accurately calculate the steering angle of inspection robot, the eight sensors symmetrical distributed on the mechanical mechanism are used for signal detection, the deviating position between the navigation line and inspection robot is obtained after weighted data fusion, the weighted coefficient calculation process and location of steering angle relationship curve are given. This scheme is very suitable for application on the microcontroller because of the low computational complexity and easy control in program. Introduction With unmanned substation of step by step, the scene of the PV power plant inspection robot will become a trend. Because of the inspection robot trajectory is relatively fixed, so the electromagnetic navigation is a kind of low cost, high reliability of navigation [1,2]. In electromagnetic navigation early research, mainly composed of the position and direction detection [3], with the growing popularity of the application, the technology gradually turned to free-space field positioning and navigation applications [4,5]. The electromagnetic navigation technology has good development prospect because of its practicability. In order to ensure the electromagnetic navigation robot along a predetermined orbit and reliable operation, the magnetic field signal detection and steering control solenoid are an electromagnetic rail navigation robotics research focus. Electromagnetic sensor IIR filter can effectively improve the linearity of the sensor data [6], steering servo control based on fuzzy control algorithm can improve the dynamic performance of the smart car [7], some experts had completed the electromagnetic robot navigation steering control by way of a robot positioning solution [8]. In order to get the inspection robot’s deviation from the navigation line distance, and assure the accuracy of the steering control of the inspection robot. On the basis of the existing electromagnetic navigation theory, the scheme using eight inductance sensors for signal detection, which were set up in the mechanical structure symmetrically, and calculated the inspection robot steering angle accurately by the weighted data fusion algorithm. Finally, the effect test was implemented in the inspection robot device and the test data was presented. Detection Principle and Sensor Layout Principle of Magnetic Field Detection Based on the classical electromagnetic theory of Maxwell, magnetic fields are created when the alternating electric current flows. So we can lay the wires adding in a 20 KHz frequency alternating current signal in the wheeled robot pathway, and the magnetic field can used as the wheeled robot navigation signals. The signal of magnetic field can be detected by the inductor, and the wire magnetic induction strength calculation diagram is shown in Figure 1. The magnetic induction intensity of point P which is capital r from the wire can be deduced as follow based on the Biot-Savart law. 195