Position detection method is applied in industrial production. Some of these methods can ensure positioning accuracy but poor ability to resist pollution, some lower cost but positioning is not accurate. In this paper, we study the Gray bus location system can be used in linear or circular displacement detection. Gray bus location system has a precise location. Its ability to resist pollution is strong, waterproof. Gray bus location system detecting the unloading cars real time location, then, let the signal of real-time location transmitted to MCU.MCU converts the signal into switch signal to control the discharging car running. Through Gray bus position detection device and control system to work together, can realize the unloading car walk smoothly, the stop position accurately.

Due to the influence of interference signals, such as the electromagnetic interference, noise interference, temperature drift, and so on. The traditionally used metal detectors have the shortcomings of the inaccuracy and poor anti-interference ability. This paper is based on analyzing the principles and characteristics of traditionally used metal detectors, presents a new full digital beneficiation metal detector, which using MSP430 MCU as the core, the FFT algorithm is employed successfully to analyze the induction signals that collected when the metal through the induction coil, gets the amplitude-frequency and phase frequency characteristics, determines whether metal impurities through the coil by the characteristics of cross-correlation function. In the end, achieves good harmonization between sensibility and reliability.