Design and experiment of the simulated electronic corn ear based on UWB/ IMU technology

In order to explore kinematic and dynamic parameters of corn ear in the process of threshing, and reveal threshing principle and grain impact damage mechanism, a simulation electronic corn ear was designed based on ultra wide band (UWB) and inertial measurement unit (IMU) technology. The spatial positioning algorithm and impact force analysis algorithm of electronic corn ear were studied, and a simulated threshing test bench was built. Then free fall impact force detection test and comprehensive performance test of the electronic corn ear were carried out. The experimental results showed that the average detection error of free fall impact force was about 0.69 N, with an accuracy more than 95 %, and the average detection error of impact force in the process of simulation threshing was about -0.27 N, with an accuracy more than 97 %. The spatial positioning accuracy of electronic corn ear was related to the number, layout and positioning algorithm of UWB positioning base station. Unscented kalman filter (UKF) tight combination positioning algorithm had the highest positioning accuracy (about 100 % probability of positioning error within +/- 0.15 m) under the condition of non -line of sight (NLOS) (5 base stations, 3.2 m height difference). Extended kalman filter (EKF) tight combination positioning algorithm had the second highest positioning accuracy (about 100 % probability of positioning error within +/- 0.2 m), followed by kalman filter (KF) loose combination, UWB single positioning and IMU single positioning algorithm. The results are helpful for obtaining kinematic and dynamic parameters in the process of ear threshing and separation, understanding the mechanism of efficient and low -damage threshing, and provide a basis for the segmented optimization design of subsequent devices.