Control system provides the digital servo control, Wave generation for the axial loading, data acquisition, hydraulic control etc. for the continuous operation of the system.
(a) Signal Conditioning & Controlling Unit VERTEX Servo controller basically consists of signal conditioning unit and controlling unit. Signal conditioning unit consists of conditioning modules for various transducers (e.g. Load Cell, Displacement Transducers etc.) that receives the output signal from these sensors and amplifies and process that signal as per the requirement and transfer it to computer through dedicated cables where it is accepted by the data acquisition system. The out put from the signal conditioning unit for each transducers range from 0-5V.The controlling unit controls the movement of the RAM with respect to the signal input on feed back basis either from LOAD CELL or DISPLACEMENT sensor.
It consists of dedicated servo-controller card that gives the desired processed signal through the P.I.D controller to the servo valve to operate either of the control modes i.e. Load mode or Displacement mode. It also sends the signal to computer and accepts the command from the software to operate in desired manner. The system can generate sine, triangular or square wave form and also can accept external input wave form as generated in the field. The programming facility is given to operate the system in STATIC MODE at programmed rate of loading in both Load and Displacement controls. In DYNAMIC MODE the cycling can be done at a frequency from 0.01Hz-10Hz or even higher.
Specifications of Controller
- Auto PID operation with auto loop shaping servo operation
- Closed loop update rate is 10 kHz
- No. of control channels- 2 (Load/Displacement)
- Demand Wave generation – Sine, Triangular, Square, Random wave forms and Ramp signal
- High speed Data Acquisition card with 100 kHz sampling rate and 16-bit resolution acquires data from the signal conditioning and controlling unit
- System accuracy – Load accuracy : ±0.5% of indicated value of Load Displacement accuracy: ± 0.5% of indicated value
- Two types of Loading – Dynamic (for fatigue test) and Static (Ramp)
- Dynamic Frequency Range – 0.01Hz to 10Hz or even higher (Note: The stroke of actuator depends upon the frequency of operation. Performance curve will be provided along with the offer)
- Static Ramp rate: Load control mode – 1kN/sec – 10kN/sec Displacement control mode- 0.001mm/sec – 2mm/sec.
- Environmental Temperature – 0OC to + 60OC
- Relative Humidity – 10% to 85% noncondensing
- Supply Input – 220-240 VAC, 50 Hz
(b) Computer for Controlling and Data acquisition System is provided with dedicated computer of latest available configuration with built in data acquisition card and wave generator.
Data acquisition card
The PCI Bus advanced data acquisition card provides the following advanced features
- 32 bit PCI- bus
- 16-bit Analog Input resolution (Higher bit resolution up to 24bit)
- Auto Scanning Channel selection up to 16 channels.
Up to 100 KHz A/D Sampling Rates
- 16 Single ended Analog Input channels
- Bipolar Input signals
- Programmable gain of x1, x2, x4, x8, x16
- Input range: +/-10V, +/-5V, +/-2.5 V, +/- 1.25V, +/-0.625V
- One 12-bit Monolithic multiplying Analog Output channel
- 16 Digital Output and 16 Digital Input channels
- 4 extended Digital Input and Digital Output channels on the 37 – pin con nector
- 3 Independent programmable 16-bit down| counters.
- Three A/D Trigger modes: Software Trigger, Programmable Pacer Trigger and External Pulse Trigger
- Pre-trigger control
- Internal DC-to-DC converter for stable Analog power source.
Control Software
Controlling and On-line Data Acquisition to PC through user friendly software and Statistical Analysis of the results obtained.
Salient Features
- Windows based user friendly software
- Capable of testing Triaxial Test, Unconfined, Indirect Tensile, Creep Tests and normal Compression Tests on Rock specimen up to NX size in both Cyclic (Frequency Range-0.01Hz-10Hz) and Routine Static testing
- Four different types of axial loading can be given to the sample- Sine, Square, Triangle and Ramp signal
- Programmable Loading parameters – Frequency, Base, Amplitude etc.
- Programmable rate of loading in Static Tests
- Programmable cell pressure and automatic controlling of cell pressure
- Computer/Software programmable Safety Limits for each load & displacement
- Independent Taring of each channel
- Facility to hold the loading and restart loading during the test.
- Shows number of cycle on screen
- Store the number of cycles in Dynamic test
- Real time display of Load v/s Displacement, Load v/s Time & Displacement v/s Time graphs
- On-line display of load, displacement and Confining pressure
- Auto adjustment of graph scales
Analysis Software
- Plotting of following graphs a Load v/s Time
b) Displacement v/s Time
c) Load v/s Displacement
d) Stress v/s Strain
- Calculation of various results (Young’s modulus, Maximum strain, Compressive Strength etc.)
- Facility to plot the data for a selected run
- Comparative analysis using multi graphs
- Statistical analysis of the test results
- Batch Summary Report
- Detailed Summary Report
- Advance Statistical Analysis
- Facility to print Test Reports
- Facility to Export Data to MS Excel
