Studies On Radio Wave Propagation Mechanisms Through Plantation Forest And Control System Of Pruning Machine

Pruning is one of the most important and necessary step of cultivating plantationforest. The traditional pruning machine has low working efficiency, high casualty, limitedprunning height and is difficult to meet the need of fostering the large area of commercialplantation in China. So the key method is to develop an automatic pruning technology,which should be safe, high quality and efficient.Based on studying of the theory of remote control and wireless electromagneticpropagation mechanisms, this paper synthetically applied electric field intensity measuringtechnology, electric circuit design and optimal technology, wireless remote control andcode-decode technology and the theory of ergonomics. The purpose of this study is todevelop the automatic pruning machine with independent intellectual property right. Themain contents and conclusions drawn in the dissertation:1. This thesis works out the study object and remote control mode of the controlsystem of automatic pruning machine.2. Based on analysing of the theory of electromagnetic propagation mechanisms, forthe first time, the electric field intensity predict mode of ultra-high frequency(UHF)wireless frequency band in plantation forest was accomplished. The average accuracy isabout 0.90 in the experiment in oriental arborvitae plantation in Beijing West Mountainarea. So the predict mode could provide theoretical basis for designing telemetry, wirelessremote control, wireless data circuit in plantation forest efficiently. After analysing theexperimental data, the relative patameters and the effective control distance of wirelessremote control transmitting and receiving system of automatic pruning machine weredrawn in the paper.3. The wireless remote control system of automatic pruning machine by using CPLDtechnology, numerical code-decode technology and many other factors were developedcreatively. The race hazard was efficiently eliminated through optimizing the internallogical circuit of CPLD to ensure the accurate logical control of the whole control system.As the core of the control system, CPLD implements the most logic functions and thecircuit design is simplified and the equipment size is downsized by 40%. Additionally thesystem reliability and design flexibility are improved greatly.â‘  ASK modulation and interruptible transmitting in remote control system couldgreatly decrease power dissipation. By calculating, the rechargeable battery with 800mAhcapacity could work about one year for transmitting system without self-discharge.â‘¡ Many optimal method were used in the system design, such as code-decode,address matching of remote control system, electrified regulation between CPLD andtransmitting circuit, working logical between control system and gasoline engine, etc. toimprove the transmitting data stablity, reliability and function safety of the machine.â‘¢ The self-developed special interface circuit, feedback control circuit and drivingand isolation circuit for direct electromotors improve the electromotors' control acurracyand make the remote control system could avoid the electromagnetic interference causedby electromotors effectively.4. Finally, the wireless remote control display of the automatic pruning machineBSR-Z23-001A was reasonably designed. The ergonomics principle serves as a basis forintegration testing. The debugging result show that the system has good performance, thecontrol display structure is clearly and the operations are easy, the reliable control distanceis 90m which correspond very well with the electric field intensity predict mode and couldmean the control require of the pruning machine absolutely.This research gets the wireless remote control system of BSR-Z23-001A automaticpruning machine by combining the electromagnetic propagation mechanisms, electric fieldintensity measuring, electric circuit simulation and optimal. The control system has theadvantages of easy and reliable operation, high efficiency, anti-interference, economizingon energy. It provides a new idea for pushing forward the automatic scheduling for forestrymachine.