Decentralized Control

An overall control system for safe and reliable operations.

Nowadays there is a continual demand for lift systems to be increasingly sophisticated which conventional, centrally controlled systems cannot cope with, owing to the fact that the demands on the control system are increasing whilst the cycle times get shorter and shorter. To overcome this problem the control, sensor and actuator systems have to be decentralized.

Implementing additional intelligence on the sensor and actuator levels and establishing a field bus system contributes to the realization of a decentralized, intelligent, control system enabling horizontal communication with inherent intelligence on the sensor and actuator levels, thus leading to flat controlling structures. For this purpose controlling functions are distributed among the intelligent sensors and actuators. High flexibility, modularity and additional intelligence in each sensor, and the possibility of shorter cycle and reaction times enabled by parallel controlling structures, enables many possibilities in the field of lift control systems. It is essential in this context to shift from the client/server principle to the producer/consumer model. In the lift industry we take the application profile CiA-417 as a basis. In this CANopen-profile the messages from all the sensors and actuators within a lift group are defined in so-called virtual devices. It is not the changes that are transmitted at the input (e. g. input No. 277 from low to high) but the message from the virtual device (up call door A on landing 3 for group controllers 2 and 3). The message is entirely generated in the smart sensor and is placed at the disposal of all bus participants of the lift group, and can make an “intelligent” actuator take an action. Complex tools are required to configure the virtual devices. For the lift industry, CANwizard^® is such a tool. CANwizard^® enables the field personnel to simply configure virtual devices, save the system configuration, update the software of the different components and diagnose the messages at bus level. Intelligent filters which prevent showing the complexity of the system when working with CANwizard^® are available.