Hydraulic trainers
The two Hydraulic Trainers offer the ability to construct hydraulic circuits using the mounted elements, quick-connect hoses, and installed pump. The maximum flow and pressure produced are 2.7 GPM and 500 psi, respectively. Available hydraulic circuit elements include:
- 5 GPM analog flow meter
- 1000 psi analog pressure gauge (2)
- One-way flow valve (2)
- Variable flow control (needle) valve
- Pressure compensated variable flow control value
- One-way variable flow control valve (2)
- Manually operated, closed-center, 4-way directional control valve
- Solenoid operated, open-center, 4-way directional control valve
- Double-acting, single-rod piston actuator, 6 inch stroke
- Double-acting, single-rod piston actuator, 12 inch stroke
- Piston accumulator with gas precharge pressure gauge
- Sequence valve
- Pressure control valve
- Deceleration valve
- Fixed-displacement hydraulic pump/motor
Electro-Hydraulic Trainers
Two electro-hydraulic trainers combine digital data acquisition and control with electro-hydraulic elements. These stands offer experiments in the adjustment of electronically controlled values, system identification and control methods. The stands incorporate a BD101 signal conditioning card that functions as a servo valve driver with the option for input bias and scaling and a closed-loop proportional-integral controller. The card is normally connected to a PC via National Instruments hardware. The stand includes the following electro-hydraulic elements:
- D1FX proportional 4-way directional control electronic valve
- D1FH high frequency, two-stage pilot operated, 4-way directional control electronic valve
- DY3H high frequency, two-stage, 4-way directional control electronic valve
- BD15 high resolution, flow control electronic valve
- Double-acting, single-rod piston actuator, 12 inch stroke, with LVDT position sensor
Computer work station
Each electro-hydraulic trainer stand is connected to a workstation with a PC. The connection to the stand is via a National Instruments SCB-68 breakout box attached to a National Instruments PCI-6251 data acquisition card that resides inside the PC. The PCI-6251 has the capability of reading 16 singled-ended or eight differential analog inputs with 16 bit resolution at up to 1 MHz; the ability to produce two analog outputs with 16 bit resolution at up to 2.68 MHz; two 32 bit counters/timers; and 24 digital inputs/outputs. The data from the Electro-Hydraulic trainer stand is available to both MATLAB and LabVIEW environments for data collection and/or control.
Labs that students perform with the hydraulic trainer include measuring flows and pressures associated with different hydraulic circuit elements and developing algebraic models of hydraulic elements. Labs that students perform with the electro-hydraulic trainer (right) include working with servo valve electronics, dynamic system identification and closed-loop control.