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Lab: Using an industrial PID controller (Fuji PYX5)

What the lab is about

In this lab you will get experience in using an industrial PID-controller, the Fuji PYX5 (price approximately NOK 3300). The controller will be used to control the rotational speed of a DC-motor.

Equipment

  • Industrial PID-controller: Fuji PYX5. Manual in PDF format. (The same manual in paper format will be handed out when the lab work starts.)
  • DC-motor

Practical information

Room: C212/213. Supervisor: Finn Haugen.

Preparation

As a preparation to the lab you should read the following parts of the manual before beginning the practical work:

  • Section. 5.4 (PYX5/9 Wiring Diagram). Comments:
    • In this controller the measurement signal is assumed a voltage input signal between terminals 16 and 18.
    • The control output signal is a current signal at terminals 13 and 14, cf. the upper figure at page 27. However, since the lab process to be controller in this lab assumes a voltage control signal, a resistor is mounted between terminals 13 and 14. The voltage drop over this resistor is then used at the actual control signal.
  • Page 30. Our controller is PYX5.
  • Ch. II (Front Panel Layout)
  • Ch. III (Operation Procedure), Sections 1, 2, and 3.
  • Ch. IV (Setting Input and Output Types).
  • Ch. V (Functions): Read about the following functions:
    • Auto-tuning
    • Control function, but only 1. Normal PID Control.
    • Alarm, but do use much time on studying the details about alarm parameters
    • Manual operation
    • Output monitoring
  • Ch. VI (Set-Up Parameter):
    • Input filter
    • Control type, but do not care about the fuzzy controller
    • Ouput limits
    • Setpoint value limits
    • Direct/reverse control action
    • Control processing time

Tasks

  1. Do the following tasks on your own (in student groups):
    1. Cf. Ch. IV (Setting Input and Output Types). Set the parameters LOCK = 3 and PVT = 4111. Also set PVF = 100, PVB = 0, and PVD = 0. Do not change the position of the Input selection switch nor of the Output selection switch. What are the meanings of the parameter settings?
    2. Set the parameters as indicated below, cf. Section 5 Parameter List in the appendix (not all parameters in Appendix 5 are available in the present controller). Find from the manual the meaning of each of the parameters. The parameters in the list below is in same order as they appear in the controller. You have actually already set the parameters given in parenthesis below in Subtask a above.
      • (LOCK = 3)
      • OUT1: No setting required.
      • MOD = Man (= Manual)
      • AT = OFF
      • P = 100
      • I = 0
      • D = 0
      • AR = 100
      • MAN = 0
      • AL1T = 0001
      • AL11 = 90
      • A11H = 1
      • AL2T = 0002
      • AL21 = 10
      • A21H = 1
      • Loop = 0 (dont care about the meaning of this parameter)
      • (PVT = 4111)
      • (PVF = 100)
      • (PVB = 0)
      • (PVD = 0)
      • TF = 4.0
      • SFT = 0
      • SVH = 100
      • SVL = 0
      • CTRL = PID
      • DT = 0.5 (the effective value of this parameter is 0.5 no matter the value set)
      • REV1 = REV
      • TC-1 = 2 (this parameter is however not active)
      • MV-H = 100
      • MV-L = 0
      • BURN = 1 (don't care about the meaning of this parameter)
    3. Connect the controller to the process as follows:
      1. Controller input terminal no. 16 to Tachometer minus (not plus)
      2. Controller input terminal no. 18 to Tachometer plus (not minus)
      3. Controller output terminal no. 13 to Servo amplifier input ("Styrespenning") plus
      4. Controller output terminal no. 14 to Servo amplifier input ("Styrespenning") minus
    4. With the controller (still) in manual mode (open loop control): Adjust the manual control signal so that the speed is approximately 50% (you can adjust the control signal with the controller in Operation Mode). Apply a small approx. constant load torque to the motor (use your finger). What is the steady-state control error (in %)?
    5. Set the controller in automatic mode (closed loop control). Set the setpoint equal to 50%.
      1. Execute auto-tuning. What are the resulting P-, I- and D-values? What is the value of the controller gain (Kp) that corresponds to the P-value from the auto-tuning?
      2. Does the stability of the control system seem to be ok? (Excite with a step in the setpoint.)
      3. Set the setpoint to 50%. Apply a small approximately constant load torque to the motor (break the motor slightly using e.g. your nail or your mobile phone or your wedding ring). What is the steady-state control error (in %)? Explain!
      4. Set the setpoint to 90%. Again apply a small approximately constant load torque to the motor. What is now the steady-state control error (in %)? Explain!
    6. How does the control system behave if the controller mode is changed from reverse action to direct action (denoted both "direct" and "normal" in the manual)? Is this behaviour acceptable?
  2. In this lab you used the Fuji PYX5 controller for controlling a physical process. Suppose you wanted to test the various features of the controller by letting it control (in a control loop) a simulator of the process. How could you in practice build such a testing system (suggest software and hardware)? By the way, what is a Hardware-in-the-loop (HIL) system? (Check the Web for a definition or explanation.)

Updated Nov. 8. 2005 by Finn Haugen, teacher. E-mail address: finn@techteach.no).