Control system design for multi-functional bath chair

Bathing is one of the most difficult nursing projects for taking care of elderly people. Multi-functional bath chair is an effective method to keep the old people away from danger and hazard of bathing. Control system is a guarantee for the various functions of multi-functional bath chair. This paper designs a control system based on microprocessor STM32 for the multi-functional bath chair. The hardware of the control system includes six modules: artificial input module, position detection module, main control module, servo-driven module, executable module and user notification module. Corresponding with the hardware, the software contains main program module, lifting module and posture adjustment module. The control system realizes the functions, including lifting, posture adjusting and the armrest linkage by controlling linear actuator, motor A (back), motor B (linkage) motor C (linkage) cooperated with mechanical structure. An experiment, conducted to verify the realization of functions of the control system for multi-functional bath chair, shows the high safety and reliability of the designed control system.