Design and experiment of a simulated electronic corn ear based on multi-sensor information fusion

To explore the mechanism of grain breakage during the threshing of high-moisture corn ears, this paper designed a simulated electronic corn ear (SECE), which could be threshed. It was embedded with a ultra-wideband (UWB) module, a inertial measurement unit (IMU) module, and a flexible film pressure sensor. The UWB/IMU coupled positioning algorithm, UWB ranging outlier removal algorithm and impact force detection algorithm were proposed to detect the kinematic and dynamic parameters of SECE during threshing. To verify the working performance of SECE, we conducted tests on dynamic impact force detection, static force detection, spatial positioning, and corn threshing. The dynamic impact force detection test results indicated an average detection error of 0.91 N, a maximum error of 2.25 N, and an average detection accuracy of 98.15 %. The static force detection test results showed an average detection error of 2.47 N, a maximum average detection error of 7.25 N, and an average R² of 0.9874. The spatial positioning test results indicated that the UWB ranging outlier removal algorithm could effectively reduce the impact of non-line-of-sight (NLOS) on the positioning accuracy of SECE, and the UWB-IMU coupled positioning algorithm could further improve the positioning accuracy. The unscented kalman filter (UKF) tightly coupled algorithm had the highest positioning accuracy, followed by the extended kalman filter (EKF) tightly coupled algorithm, and the kalman filter (KF) loosely coupled algorithm. Using the UKF algorithm, the root mean square error (RMSE) of the X ,Y, and Z axes position of SECE could all be within 0.12 m, with a probability of exceeding 85 % for errors less than 0.15 m. The corn threshing test results showed that the SECE could effectively detect the motion trajectory, dynamic impact force and static force within the threshing device. This research provided a new technical means for analyzing the kinematic and dynamic parameters of corn ears under threshing conditions and offered a new method for studying the principles of grain breakage.