Research On Embedded Control System For Electric Massage Chairs Based On PETRI-Net

As economy development and people livings elevation in our country, electric massage chairs, being main health-care apparatus in family, are more and more favorable. Electric massage chairs are typical electromechanical products which are being developed to intelligent products and household health-care centers. In order to improve technical level and enhance market competitiveness of homemade massage chairs, this dissertation does researches on the embedded control system for massage chairs by applying the embedded operation system, PETRI-Net and other new technologies. According to the aspects of hardware, software and massage manipulations, the following main research contents are done.1. The combination of MCU (Micro Control Unit) and DSP (Digital Signal Processor) is used as the control unit in hardware, and the modules completed include: keyboard and display, power and reset, monitoring, data collecting, logic control, converter of bus voltage, MCU and its expansions, DSP and its expansions, dual port RAM (Random Access Memory) and motor driver. Also, the inter-locked circuit is designed to ensure the safety of motor driver module.2.μC/OS- II is uesed as the core of control system in software, and is implanted in MCU and DSP.3. PETRI-Net is applied to model the motor control module, and reachability of this model is analyzed to make sure no deadlocks and conflicts among its functions.4. Algorithm RMS (Rate Monotonic Scheduling) is applied inμC/OS- II 's task scheduling mechanism, to make the tasks work concurrently by converting the aperiodic tasks into periodic tasks, and ensure the good responsiveness of tasks. The limited-span of task function is added toμC/OS- II to improve the stableness of system.5. Massage manipulations learning ability is designed to satisfy the consumer.The research in this paper is done in the massage chairs design process in arelevant company, and its result is successfully applied to a massage chair product. The practice shows that the embedded control system could shorten product design time, reduce product developing cost, elevate enterprise technology level and enhance market competitiveness of homemade massage chairs.