CANopen Safety in bridge inspection vehicles
- Fig. 1: The bridge inspection equipment from Moog reduces wiring and at the same time processes safety monitoring of the sensor and actuator signals according to safety category 3.
Source: CAN Newsletter June 2006
By Dietmar Brüss (ifm electronic)
The bridge inspection equipment is to reduce wiring and at the same time to process safety monitoring of the sensor and actuator signals according to safety category 3 (to EN 954) required by TÜV (German inspection authority) and the German employers’ liability insurance association. Since this application could not be implemented in one individual safe controller module, only complex additional wiring to other external safety components could have solved this requirement without the use of CANopen Safety.
The bridge inspection equipment can be used on the road and/or on rail depending on the design. Due to the design of the vehicles, obstacles such as railings, noise barriers or crash barriers can be overcome. In its working position underneath or alongside the bridge the unit can be moved sensitively. Basket-type units can also be used as mobile elevating work platforms.
Irrespectively of its type - platform or basket - the safety of the workers and the operators has to be ensured at all times. The control modules process all sensor and actuator signals and the control signals from the remote control. Both safety controllers are exclusively used for the processing of all safety-relevant sensor and actuator signals. The electronic and electromechanical end switches connected prevent, for example, that the vehicle passes into an unstable position during set-up and work. Before there is a risk of tilting, the relevant hydraulic pumps are switched off. The platform or the basket can then only be moved into a safe, stable position.
