Design Of Large Grain Noodle Autonomous Patrol Robot Control System

Grain is a strategic reserve material,and ensuring the safety of grain storage is a strategic task that my country needs to stick to for a long time.In China,the grain storage time is usually longer.In order to prevent insect pests and grain deterioration,in addition to poisoning and the fumigation of food,some grain depots will also use low oxygen and high carbon dioxide environment for grain storage,and these environmental factors will harm the personal safety of the staff in the grain silo.Besides,due to the particle fluidity of the grain,it is easy to sink into when the staff walk on the grain surface of the grain silo,so it is necessary to lay a walkway plate in the middle of the grain silo for the staff to enter the silo for viewing and sampling.A comprehensive view of the granary is not easy because of the single storehouse capacity is large.In order to ensure the safety of the staff and make up for the shortcomings of the traditional manual viewing mode,a robot that patrols the grain surface is designed.In order to ensure that the robot walks smoothly and autonomously on the grain surface,the design of the control system has become the design point of the grain patrol robot.According to the characteristics of the granules of the grain pile,the caterpillar robot is selected for the robot inspection system.In order to ensure that the caterpillar robot walks smoothly and freely on the surface of the grain pile,the weight,structure and load target of the crawler chassis and frame are considered to determine the dynamic design goals of the caterpillar robot.The weight of the track chassis and frame is 50 kg,the size is 1200?1000?600 mm,the maximum load includes a total of 100 kg of battery,the maximum climbing angle is 30° and the maximum travel speed at full load is 1.0m/s.According to the dynamic goal,determine the rated torque and rated power of the brushless DC motor.In the end,determine the parameters of the motor and power battery.According to the power of the brushless DC motor,the corresponding motor drive controller is designed.Through the relevant design of the motor drive control circuit such as inverter circuit,drive circuit,hall commutation detection circuit,current sampling circuit,etc.,the forward rotation,reverse rotation,acceleration and deceleration of the brushless DC motor are realized;PID speed regulation is designed to achieve accurate control of the motor speed of the crawler robot;by establishing a turning model,determining the relationship between the speed of the inner and outer drive wheels and the turning angle during turning,designing an electronic differential algorithm to achieve the left and right turning motion control of the caterpillar robot Finally,the overall design of the motor drive controller is completed,and the caterpillar robot walks smoothly on the grain surface of the granary.In order to ensure that the grain surface inspection caterpillar robot can autonomously walk on the surface of the grain pile,a high-precision ultra-wideband indoor positioning system is built based on the DW1000 module.The simulation and analysis of the classical positioning algorithm based on time difference of arrival(TDOA)shows that the positioning accuracy of Chan's algorithm is high in the line-of-sight environment.However,factors such as the movement of people in a complex environment and the obstruction of obstacles can hinder the transmission of ultra-wideband signals,causing non-line-of-sight(NLOS)errors,which lead to the decrease in the positioning accuracy of Chan's algorithm.Based on the unscented Kalman filter algorithm(UKF),the information contained in the observations can be fully excavated.For the UWB indoor positioning system,an improved UKF algorithm is proposed,which is combined with the Chan's algorithm to improve and the positioning accuracy.The hybrid positioning algorithm combining the improved UKF algorithm and Chan's algorithm first completes the initial positioning by Chan's algorithm,removes the TDOA ranging value with larger error,and then performs the second accurate positioning through the improved UKF.The experimental results show that,compared with Chan's algorithm,this algorithm improves the positioning accuracy of most points in the grain surface of the granary by about 30%,which effectively reduces the interference of NLOS error.In addition,the improved UKF in the hybrid algorithm simplifies the calculation of the state prediction vector and its covariance matrix,and reduces the complexity of the algorithm while achieving high positioning accuracy.Based on the completion of the above key technologies,a caterpillar inspection robot control system is designed with STM32F429 as the core,the control system consists of a motor drive controller,an ultra-wideband positioning module,a lidar obstacle avoidance module,and a wireless communication serial port module.The patrol robot control system receives the target position command from the host computer through the wireless communication serial port module,determines its position through the ultra-wideband positioning system and calculates the distance value between the two,and forwards to the direction of the distance value from the target position to its position continues to decrease,the control system drives the caterpillar robot to move,and the collision avoidance is avoided by the laser radar during the movement.After repeated tests on site,the staff can control the caterpillar robot to reach the set destination through instructions,and realize the autonomous inspection of the caterpillar robot on the grain surface of the granary.