| In recent years,with the continuous development of robot technology,people's intelligent requirements for mobile service robots have been continuously improved.In order to ensure that the robot does not cause damage to the fuselage when walking in an unknown environment,the robot obstacle avoidance system should be designed reasonably.Traditional robots use contact-type collision sensors,which are triggered when they touch obstacles,so it is easy to cause damage to household environment and noise interference.Therefore,the use of non-contact detection technology is imperative.Traditional non-contact detection technologies include lidar ranging technology,infrared ranging technology,ultrasonic ranging technology,etc.Among them,the range of infrared ranging technology is small and easy to be interfered by the color of the object and the ambient light,so infrared ranging technology has poor adaptability.Lidar ranging technology is expensive and costly.But ultrasonic ranging technology has good directionality and wide application range.Therefore,this paper uses ultrasonic ranging technology with high ranging accuracy and strong environmental adaptability to realize the obstacle detection function of robot.Firstly,this thesis analyzes the necessity of the construction of cleaning robot system,and points out the core functions of the system.Secondly,it expounds the principle of ultrasonic sensor ranging and the causes of ranging errors.And according to the influence of environment on sound waves,the design of ranging system based on odometer is proposed to correct the sound velocity error caused by environmental temperature and humidity.Thirdly,the hardware framework of the obstacle detection system based on ultrasonic sensor is designed.The ultrasonic ranging module of two engines and three receivers is used to increase the ranging range of the robot,and the interference between the modules is solved by increasing the shockproof load to improve the recognition performance of the sensor.Therefore,the design of hardware structure can meet the ranging requirements of cleaning robot.Then the robot software algorithm is designed based on STM32F103RCT6 and the robot's motion position model is established to realize the robot's heading control,and in the case of extracting the typical working scene of cleaning robot in the home environment,the robot's motion path is designed.The fuzzy database is designed to plan the cleaning robot's action path in the home environment to avoid obstacles.In addition,the method of crosstalk prediction is used to eliminate the acoustic diffuse caused by the environment and solve the diffuse effect caused by the complex environment.Finally,the feasibility of obstacle detection and ranging system based on ultrasonic sensor is verified by experiments. |
