Positioning Method Of Mobile Robot Based On Ultrasonic And Track Calculation

Ultrasonic positioning technology is one of the indoor positioning technologies for mobile robots.Compared with the positioning technology based on machine vision and infrared signal,ultrasonic positioning technology has the advantages of lower cost,high positioning accuracy and no harm to human body.There are still some problems in the ultrasonic positioning research,such as the blind area of the ultrasonic device,the noise in the environment and the ultrasonic system and the lag of the envelope signal generated by the ultrasonic.In view of the above problems,the following work has been carried out:Aiming at the blind area problem of ultrasonic device,an ultrasonic geometric positioning algorithm is adopted.Compared with the traditional ultrasonic positioning algorithm,this algorithm can expand the receiving range of the ultrasonic receiver by changing the rotation angle of the steering gear,so as to reduce the blind area of the ultrasonic receiver.In order to solve the noise problem in ultrasonic system,digital lock in amplification technology is used to detect the envelope signal of ultrasonic.The detected signal is superimposed with the reference signal,and then filtered by low-pass filter to achieve the effect of noise filtering.The simulation results show that this method can effectively solve the noise problem of ultrasonic system.In order to solve the problem of ultrasonic envelope signal lag,a detection method based on least square method is adopted,and a combined positioning method is proposed.The ultrasonic positioning system and dead reckoning positioning system are combined through extended Kalman filter algorithm.The advantages of dead reckoning,such as small cumulative error and good stability,make up for the defects of ultrasonic positioning system.The simulation experiment of mobile robot circle positioning is carried out for this algorithm,and the positioning results of ultrasonic positioning algorithm,dead reckoning positioning algorithm and combined algorithm based on extended Kalman filter are compared and analyzed,which proves the effectiveness of this combined positioning algorithm.