The control rack is designed to control and monitor durability and performance tests performed on a hydraulic test rig. The control rack is purpose-built to control a specific test rig.
The control tower has a distribution system providing mains power and 24V DC to the rack equipment. Separate power supplies are used for the hard-wired controls, instrumentation and the servo system.
The PC-based data acquisition and control system utilises a National Instruments PCI card with BNC breakout boxes for flexibility of signal connection.
Signal conditioning for load cells, strain gauge pressure transducers and an LVDT is provided by an instrumentation rack of Fylde manufacture containing a number of circuit board modules. Signal processing for thermocouples and flowmeters is provided by a DIN rail-mounted module for each signal channel.
Interfaces for relay inputs and outputs are provided by a National Instruments rack mount unit providing relay and opto-isolator connections to the system of 24V control relays, solenoid valves and sensors.
The unit on test is controlled by a rack-mounted module provided by the end user. Analogue signals link this UUT controller to the test rig PC.
The unit on test is subjected to a load that is applied by a hydraulically actuated ram. This hydraulic system is controlled a microprocessor-based servo unit of Tiab manufacture. The servo unit provides ready access to the control parameters (loop gain, integral control and differential term) by the test rig PC.
The test rig PC described here has software that was written and commissioned by the end user. Mecelec Design can offer bespoke software for test and production applications written by a knowledgeable and experienced team working with the National Instruments LabVIEW platform.