Research On Control Technology Of Household Robot Based On Android Phone

The household robot integrates with vision, temperature, humidity and smokesensors, which makes all-round monitoring for family environment. Utilizing Androidphone of good portability and3G mobile network of wide coverage to remotelycontrol household robot, users can know of the family status anywhere and anytime,which plays an important role to enhance service level of household robot and promoterobot into family life.A remote control system for household robot is developed, which is divided intoserver, client and lower computer. The server program runs on tablet PC with windowsOS, the client program runs on smartphone with Android OS. Function requirementsof the system are analyzed. Function modules are classified as remote videosurveillance, remote motion control and remote transmission of sensor data. Thecommunication channel based on3G network is established between server and client.The involved threads of server and client and running process of system are introducedin detail.A uniform LibVLC interface provided by VLC video framework is used to realizeremote video surveillance between server and client. The server program is developedwith MFC, and dynamic link library of VLC is invoked to realize camera imageacquisition, video encoding and RTP packaging. RTSP protocol is used to interact withclient and control the transmission of RTP message, and streaming transmission ofvideo is implemented. H.263, MPEG-4and H.264algorithms for video coding areprovided to adapt to different network qualities and mobile phone hardwareperformances. A strategy of adjusting image quality based on packet loss rate feedbackprovided by RR message of RTCP protocol is designed. In client program, JNItechnology is used to invoke so library of VLC compiled under Linux OS in Java, andrealize the reception and sorting of RTP message, decoding and playing of videostream. The RR message is sent from client to server to provide statistical informationof RTP message in the period at the same time.The CSocket class is used to realize socket communication between server andclient, and the MSComm control is used to realize serial communication betweenserver and lower computer. The lower computer program runs on ATmega128L MCU,and robot motion control, sensor data acquisition and serial communication functionsare realized.The remote video surveillance, remote motion control and sensor informationdisplay functions are validated under WIFI and3G networks respectively. The network transmission bandwidth and image clarity of real-time video under differentparameters are compared. The real-time performances at different encoding algorithms,resolutions and frame frequencies under WIFI and3G networks respectively are testedusing two Android phones. The results show that transmitting real-time video stream atH.263algorithm, resolution of QCIF and frame frequency of5pfs via3G network, thetransmission delay is about5s, the video frames are fluent and relatively clear. UnderWIFI and3G networks, the transmission delay of motion control instructions andsensor information is within1s, and the real-time performance is very fine.