Purpose of research. The article is devoted to the development of an algorithm for controlling the movement of a controlled mobile platform of a passive mechanotherapy ankle joint apparatus. One of the most common injuries sustained by humans is damage to the ankle joint in sports, domestic, industrial exercises, and as a result of car accidents. Falls from heights with a landing on the feet, including parachute jumps, also often result in ankle injuries. In order to increase the effectiveness of rehabilitation, mechanotherapy is usually used. The relevance of the topic is related to the high efficiency of robotic rehabilitation devices, which, thanks to back-linking and electrically controlled actuators, can perform lower limb movements in an optimal way.Methods. The structural diagram of the device control system has been developed. The proposed algorithm uses the strategy of paralleling control actions with the use of corrective and reference controls to calculate control voltages. Presence of force-moment feeling system enables to estimate change of reaction value in time and timely fix the moment of spastic effects appearance, muscle contracture and automatically make changes in foot movement laws in order to exclude patient's traumatisation and pain syndrome elimination.Results. A methodology for constructing the desired dependence of foot rotation angles on time in the sagittal and frontal planes is proposed. We have developed an operating algorithm for the laws of motion and decision-making block, an algorithm for generating control voltages from the reference model, an operating algorithm for the voltage correction block, and an operating algorithm for the reference model correction block. As a result of virtual tests on the mathematical model of the device, we obtained the basic patterns of motion of the actuator in the form of dependences of the rotation angle of the platform from the time.Conclusion. The results of testing the device show that controlling the movement of the actuator for active-passive mechanotherapy of the ankle joint using the algorithms described in the article is reasonable.
