Structure Design and Control System Realization of a Novel Traction Device

Traction therapy is a common method for bone disease treatment and recovery. Aiming at the shortage of bulky size and low precision of the existing traction bed, a new kind of small, safe and stable traction device and its control system are designed in this paper. The device adopts separated driving mechanism, which drives rope-winding wheel to rotate to create traction force, which detected by tension sensor based on swing arm mechanism and a spring, through gear set composed of planetary gear train and a small gear. ATmega128 is chosen as the main processor to realize closed-loop control to promote the precision of traction force. Human-machine interaction (HMI) is based on an 8-inch serial ports touch screen, supplying friendly and simple control. Theoretical analysis and experimental verification show that the precision of traction force has been greatly improved on the traction device, only ±1% error in 0~60kg and ±2% error in 60~90kg.