PA-RR-260-8-C-24-C-315-00 redundant rotary servo actuator

The PA-RR-260-8-C-24-C-315-00 is a redundant rotary servo actuator from Pegasus Actuators, designed for safety-critical unmanned aircraft and other unmanned systems that use control surfaces or levers driven through a rotating output shaft. It combines two brushless motors, two servo controllers and three contactless angle sensors in a single housing.

The redundancy is handled inside the actuator. Multiple master control units reach a majority decision, and after a motor, power stage or signal-cable fault the second channel takes over without any action from the autopilot. The autopilot only receives a warning signal. In normal operation the first motor and its power stage work, and the second is engaged after the first has failed. Pegasus states that the actuator keeps its full torque, speed and bandwidth after a single failure. The only requirement on the host is two identical command channels.

The main figures are as follows. Continuous torque is 300 Ncm and stall torque is 500 Ncm or more, with the slip clutch releasing between 500 and 600 Ncm to protect the gear train and the airframe. No-load speed is 210 deg/s at 24 V, and speed at rated torque is 135 deg/s typical. The travel angle is 315 deg with a magnetic redundant contactless angle sensor. Gear train backlash is at most 0.5 deg, and the weight is 480 g typical. Axial load on the output shaft must stay below 100 N and lateral load below 300 N.

For power, the operating range is 18 to 32 V with 24 V typical, and the absolute maximum is 34 V. At 24 V the standby current is typically 130 mA with both channels connected, and the operating current is typically 500 mA against a 300 Ncm load. Each channel needs its own power input.

The command interface is RS485 with a redundant data protocol, with baud rates from 9600 to 230400 bit/s and 115200 typical, and a switchable termination resistor built in. CANopen CiA 402 is listed as an option under a different order code. The actuator uses two Glenair Series 801 Mighty Mouse 7-pin connectors, and the aluminium case has a solid 4-point fixation. Installation frames, levers and programming tools such as PA-Control 3 are offered as accessories.

The case is protected to IP67 against water and dust, the operating temperature range is -40 to +70 degrees C, and the environmental conditions are designed to comply with DO-160 F and MIL-STD-810.

Typical applications are primary flight control surfaces, swashplate and lever-driven linkages on unmanned aircraft where a single actuator fault must not cause a loss of control.