Koncepcja systemu sterowania urządzenia do wspomagania chodu

Mechatronika, jako koncepcja budowy urządzeń jest obecna niemal we wszystkich działach techniki. Rozwój mikroprocesorowych układów przetwarzania danych, a także postęp w dziedzinie budowy układów wykonawczych i pomiarowych stwarzają możliwości realizowania przez urządzenia funkcji, które jeszcze do niedawna pozostawały jedynie w sferze marzeń. Postęp nie ominął również medycyny, a ściślej wyposażenia technicznego pracującego na rzecz osób chorych. Roboty ortotyczne, których szybki rozwój następuje w wielu ośrodkach naukowych na całym świecie, zastępują u ludzi utracone funkcje ruchowe. Autorzy pracują nad urządzeniem do pionizacji i wymuszania chodu osób z bezwładem nóg. W artykule przedstawiono koncepcję systemu sterowania opracowywanego urządzenia.

Mechatronics seems to be nowadays the leading idea of design of machines and devices. Integration of mechanic devices with the powerful microelectronic technology forced synergy effects resulting in new applications also in medical domain. Here, wearable robots are most spectacular examples. They are person-oriented robots that may be defined as those worn by human operators, whether to support the function of a limb or to replace it completely. The authors focussed their attention on the development of an orthotic robot suited for people with paresis of lower limbs (Fig. 1). The role of the robot is to improve standard of life of handicapped people. However, for safety reasons, its usage needs additional assistance of third party persons. It leads to a conclusion, that control system of the device should be designed in such a way that movements of limbs are allowed only and only in cases when all safety conditions are fulfilled. Upon this statement, the device under design can be classified as a self optimising system. The general structure of such a system is shown in Fig. 2. This system consists of: knowledge base, multi- control subsystem, communication ports and inference machines. The block diagram of automatic control system is depicted in Fig. 3. The main purpose of knowledge base is to store and update reference data for decisions upon the device performance. This data contains records of values of selected signals, collecting information about the state of the device and a robot user, in order to detect non-safety behaviour. Tilt of the user's body and acceleration of its certain parts, as well as reaction forces between feet and crushes against ground can be considered as signals useful for decision making. A structure of the control system meeting the above considerations is presented in Fig. 4. A brief survey of data transmission protocols was carried out. A survey was focused on systems used for industrial applications taking into considerations its approved high immune against electromagnetic field transients and easiness of building redundant structures of communication networks and controllers. Finally, CAN standard was proposed as a communication protocol for the device broadly used in automotive industry (Fig. 5). In the conclusions future works are presented together with the risk analysis.