Closed Loop Positioning Control

CLPC LC (Closed Loop Positioning Control)

Provides Accurate, High Cycle, Clutch Brake Positioning Control

Continuously Correcting for Stop In Position Accuracy

The CLPC is used to control a Posidyne Clutch Brake on cycling applications where very accurate stopping position is critical. Often when using a clutch brake in this application a limit switch or PLC is used to set the stop position. Because the Posidyne Clutch Brake with Oil Shear Technology is very consistent running steady, this works fairly well. However, as with any clutch brake unit, changes in temperature, cold start to hot run and other variables cause the stopping to be shorter or longer, thereby overshooting or undershooting the desired position. The CLPC corrects for this.

How they work.

The original CLPC was designed to control high cycle applications where the scan time of PLC’s was too slow for accurate positioning. It consists of the CLPC control unit and a position encoder mounted on the clutch brake output shaft. The optical encoder counts pulses back to the CLPC control. The control is then programmed via push buttons on the face of the control to index (when given a start signal) the desired number of pulses for a complete index. Because a brake will not stop the drive instantly the brake must be engaged before the stop position allowing time for the drive to decelerate to stop. This is called the “trigger point”. When first starting the drive the index distance is programmed into the control and the trigger point is set automatically. As the drive is indexed, if the stop is out of position, the trigger point automatically adjusts until the stop is in location. This typically works on a 5 index algorithm to avoid hunting. When the correct number of pulses is reached (the trigger point) the control will signal the brake to engage and release the clutch. The stop position can be adjusted by using the manual adjust setting to adjust the stop position 1 pulse at a time to the desired position. This then becomes the stop or home position. When the brake signal is received and the brake is engaged it will decal to stop within so many pulses. In operation any variation in stopping due to temperature change or load change, or torque change will cause the stop to be out of position. The trigger point (count when the brake is signaled to engage) will then be adjusted to compensate for the error. This is done on a 5 count algorithm to avoid “hunting”. The result is the trigger point continually adjust itself to maintain an accurate stopping position.

 

CLPC

CLPC Features, Functions and Capabilities

The basic CLPC Control Model LC is designed to operate a standard Posidyne Clutch/Brake in an indexing application. The CLPC-LC is programmed for the desired index distance (encoder counts). The CLPC-LC will energize the clutch valve until the trigger point, de-energize the valve and stop in position. The trigger point is self compensating to actuate the brake at the proper time to consistently stop in position and will float as conditions change. The CLPC Control Model LC is a single direction single clutch drive control.

The CLPC Control Model LC has numerous features such as:

  • Universal Supply Input – 85-264 VAC, 47-63 Hz
  • Interface – All functions adjustable with a simple menu through a display panel.
  • Program Lockout – via external cold contact.
  • Eleven Internally Tested Functions – Error Codes with descriptions displayed to identify Faults.
  • Compact Design – Door Mount or Panel Mount.
  • Always Ready – No calibration required.
  • Stall Detection – Detects a jam (no rotation of the encoder) before reaching the desired stop position and disengages the clutch.
  • Watch Dog Timer – Adjustable (100 milliseconds to 1 minute) timer which will disengage the clutch if timed out before reaching the desired stop position. Used to protect against jams which may stop or slow down the drive.
  • Encoder Resolution Settings – X1, X2 and X4.
  • Manual Adjustment – Allows a positive or negative adjustment from the home sensor position. Used to align the machine position with the home sensor
  • Emergency/Fault Stop – Abort Input allows the control to react to an external request to stop the index or prevent any further indexes from occurring.
  • In Position Output – An output to indicate when the drive has reached position. A plus or minus count can be set as an allowable in position window.
  • Optional (MIP/PLS) – Multiple Indexing Parameter groups – Capable of storing up to 16 different groups (Index Distances). Programmable Limit Switch—Capable of 4 Programmable Outputs based on position

CLPC Specifications

Electrical

  • Input Power: 85-264 VAC, 47-63 Hz., Single phase, 100 watts max., Fused @ 4 amps.
  • Encoder Input: Six Signals: A, A’, B, B’, Z and Z’; 7.2 kHz max.; 0-.3 VDC (Low), 2-12 VDC (High)
  • Auxiliary Supply: 12 VDC, 1 amp, Current limited, Short circuit protected. Used for Encoder and Home Switch.
  • Solid State Inputs: Three: 120 VAC and 24 VDC standard, Fused @ 1/16 amps, – Start Cycle, Fault Reset and Abort Cycle.
  • Program Interlock: External cold contact switch required.
  • Solid State Outputs: Two: 115 VAC standard (7 to 60 VDC available), Fused @ 3 amps, N.O. – Fault and In Position,
  • Clutch/Brake Output: One: 24 VDC, 1 amp max., Fused @ 3 amps.
  • Displays: 16 characters by 2 lines, .22” character height, Backlit
  • LED Status Indicators: Five: Channel A, Channel B, Z Channel, Clutch On, Fault.
  • Diagnostics: Eleven: Internally tested functions. Error codes and description displayed to identify faults.

Mechanical

Enclosure: Aluminum/Stainless, Black anodized, NEMA 1, IP20 Enclosure. NEMA 4, IP66 when door mounted with gasketWeight: 3.5 Lbs.

Dimensions: 6” x 6” Face x 5-3/4” Deep

Environmental

Operating Temperature: 32° – 140° F (0 – 60° C)
Storage Temp Temperature: 0° – 186° F (-18° – 85° C)
Ambient Humidity 90% non-condensing max.
Vibration 2.5 g’s, 30 to 200 Hz.

Programmability

Interface: All functions adjustable through display panel push buttons. Some of these Functions include:
Index Count Up to 65,535 pulses.
Manual Adjust ± 1/4 of maximum count.
Encoder Input Control x1, x2 and x4 operation.
Watch Dog Timer Off, 100 ms to 1 min. in 16 increments.
Push Buttons Five: Program, Menu Back, Menu Forward (Fault Reset), Increment and Decrement.
Optional (MIP/PLS) Multiple Indexing Parameter Groups – Capable of storing up to 16 different groups. Programmable Limit Switch – Capable of 4 Programmable Outputs based on position.

Typical CLPC LC Applications

Assembly Line Part Conveyor

Assembly Line Part Conveyor
(CLPC-LC Control)

Ferris Wheel Turn Over

Ferris Wheel Turn Over
(CLPC-LC Control)

Press Feeder – CLPC-LC

Press Feeder – CLPC-LC
(FTL) Feed-To-Length

Part Cut-Off – CLPC-LC

Part Cut-Off – CLPC-LC
(CTL) Cut-To-Length Control

Case Packer

Case Packer
(CLPC-LC Control)

Fiberglass Chopper

Fiberglass Chopper
(CLPC-LC)

Optical Encoders

The Optical Encoder provides the pulse counting system for the CLPC Closed Loop Position Control using a disc with precision holes and photo interrupters placed in the correct position. By sending a pulse when the interrupter sees the edge of a hole, an accurate count is made. Using two interrupters improves the resolution and the direction of rotation is also known. A third interrupter is used to establish a home position. The home position is used as a starting point for the count, which eliminates the possibility of accumulated error.

The (2) basic types of Optical Encoders are:

    1. Posidyne Mounted Encoders – are directly mounted to the output housing and output shaft of the Posidyne Clutch/Brake Unit. They are available for all sizes of Single Clutch and Dual Clutch Posidyne Units. (See each specific section for dimensions and see this section for all specifications, additional information and ordering information.)

 

  1. Double C-Face Encoders – could also be mounted on the output end of the Posidyne Unit or Motor and then be C-Face mounted to a gear reducer or mounted on the back end of a Brake Motor between the motor and the brake. These C-Face Encoders come with a 4-1/2” AK register. They can accept a 5/8” Dia. and 7/8” Dia. Shaft. (See this section for additional information and ordering information.)
CLPC Encoders CLPC Encoders

Electrical Specifications (All Optical Encoders)

Input

  • Voltage 5 to 15 VDC.
  • Current 100 mA max. (with No Line Loading).
  • Ripple 2% peak to peak @ 5 VDC input.
  • Regulation ± 5% for 5 VDC power supply.

Output

  • Type Quadrature (A & B) with zero ref. (Z) plus 1 spare channel. All with differential line driven square wave outputs.
  • PPR Posidyne C-Face Encoder – 60 count for sizes 1.5 to 10 Posidyne 90 count for sizes 11, 14 and 20 Posidyne
  • Current Sinking, 250 mA open drain (Collector).
  • Sourcing, 250 mA open source (Emitter)
  • No pull ups or downs.
  • Circuit TC1 428 Dual High Speed Mosfet Driver.
  • Latchup Protection: Will withstand 500 mA reverse output current.
  • ESD Protection to ±2000 volts.
  • High Output Peak Voltage: 1.2A peak.
  • High Capacitance Load: 1000pF in 38nS. Output voltage swing to within 25mV to ground or the control voltage.
  • Low Output Impedance: 8 ohms.
  • Freq. Response 250K CPS.
  • Symmetry 180 electrical degrees ±18°.
  • Quad. Phasing 90 electrical degrees ± 36°.
  • Rise Time Less than 1 microsecond.
  • Accuracy Within ± 0.1° from one pulse to next pulse, or 60 arc min.
  • Electrical Connection 10 pin Phoenix 1827787

Environmental Specifications (All Optical Encoders)

  • Operating Temp. 0° to 70° C.
  • Storage Temp. -25° to 85° C.
  • Humidity 95% RH Non-Condensing.
  • Vibration 10 G’s @ 50 t0 500 CPS.
  • Shock 50 G’s @ 10 mS duration.

Mechanical Specifications (Posidyne Mounted)

  • Max. Operating Speed = 3600 rpm
  • Inertia = .00916 Lb. Ft.2
  • NEMA Rating = 12

Mechanical Specifications (Double C Face Mounted)

  • Max. Operating Speed = 3600 rpm
  • Inertia = .00916 Lb. Ft.2
  • NEMA Rating = 12
  • Register = 4-1/2”AK or 8-1/2” AK