Design And Implementation Of Intelligent Wheelchair Monitoring System Based On WeChat Applet

As aging becomes more and more serious in our country,and the increasing of aging population,the users of wheelchairs are increasing.Intelligent wheelchairs provide guarantee for the quality of life and daily travel of the elderly and have high application value and wider market value.Based on the development status and background investigation of smart wheelchair at home and abroad,this paper designs a smart wheelchair that can realize positioning monitoring and control.The monitoring system in this paper uses GPS module to realize positioning.After positioning,the longitude and latitude data will be reported to the MQTT server,and the latitude and longitude of the module can be viewed on the small program anytime and anywhere.The GPS module uses the A9 G development board,which has both GPS and GPRS functions,and can realize global positioning.The intelligent wheelchair control system is divided into motion control module,obstacle detection module,Bluetooth module and voice control module,among which the human-computer interaction is conducted by voice and wechat mini program.The control system uses STM32F103C8T6 as the microcontroller,and realizes the wheelchair control system with the relevant peripheral circuit and sensor.The obstacle avoidance part of the intelligent wheelchair adopts 1 way ultrasonic wave and 2 ways infrared ray to detect the obstacle information on the front,left and right side of the wheelchair respectively.Aiming at the human-computer interaction module of intelligent wheelchair,this paper designs two control modes: wechat small program control and voice control,which enrich the operation mode.The speech recognition technology uses ASR algorithm,but in the process of speech recognition,some noise may be introduced at the beginning of recording,thus affecting the final recognition effect.Therefore,LMS adaptive filtering algorithm is introduced in the pre-processing stage of speech recognition to filter the noise.However,the traditional LMS step-size algorithm has the contradiction between convergence speed and steady-state error.In order to solve the contradiction between convergence speed and steady-state error of the LMS algorithm with variable step size,a new LMS algorithm with variable step size minimum mean square adaptive filtering is proposed.Finally,the experimental simulation results show that the algorithm has a good noise reduction effect.