Ultra Motion Actuators Help Measure The Moon At 70,000 Feet

Air-LUSI Project
Photo Credit: Ken Ulrich, NASA

The airborne lunar spectral irradiance mission (Air-LUSI) is a partnership between NASA and NIST to create SI-traceable measurements of lunar spectral irradiance in an effort to improve the measurements of Earth observing satellites. These satellites monitor the weather, vegetation, ocean currents, pollution, and more. Using the light reflected from the moon as a constant absolute reference point for satellite calibration will allow for improvements to these satellites and consistency between data from different satellite instruments. Satellites will be able to calibrate in-orbit and over-time as sensors degrade.
The custom telescope used to acquire the data is installed into the wing pod of an Earth Resources-2 aircraft, which is a direct descendant of the U-2 spy plane. The ER-2 flies to an altitude of 70,000 feet allowing the telescope to measure the light from the moon above 95% of the Earth’s atmosphere. Reducing the distortion effect of the atmosphere allows Air-LUSI to characterize the spectral irradiance of the moon more accurately than ground-based measurements, and in a similar environment to the Low-Earth Orbit satellites that will make use of the calibration point.

Ultra Motion’s Role
An autonomous robotic telescope mount instrument subsystem (ARTEMIS) was created by Dr. S. Andrew Gadsden and his team in the Intelligent Control and Estimation laboratory at the University of Guelph (Ontario, Canada) in order to accurately track the moon during the flight. Two Ultra Motion Servo Cylinders were successfully employed to control the telescope’s elevation and azimuth throughout the flights. The ARTEMIS system had to operate flawlessly at 70,000 feet and in ambient temperatures as low as -60°C. External heating elements were used to maintain the temperature of the actuators throughout the flight. Custom self-heating Servo Cylinder firmware can be installed to use the motor as a heat generating element for applications that cannot make use of external heaters.
Telemetry was gathered from the actuator’s integrated controller in order to monitor the performance and health of the Servo Cylinder throughout the experiment. This included absolute position from the Phase Index contactless sensor, actuator temperature, bus voltage, and actuator phase current. Real-time data from the Servo Cylinders provide insight into the overall performance of the system and increases the confidence of the ARTEMIS for future test flights.

A demonstration flight campaign over five separate flights showed that the ARTEMIS successfully tracked the moon with a root-mean-squared-error of 0.11° tracking accuracy! The Air-LUSI experiment will continue to be used over the coming years to gather lunar irradiance data for a range of lunar phases. As the data set grows, a higher fidelity lunar spectral irradiance model can be produced and allow for improvements to a significant amount of Earth-observing satellites.

Read more about this project.

A video overview of the Air-LUSI mission is shown below:

Air-LUSI Project
Photo Credit: Ken Ulrich, NASA

Air-LUSI Project
Photo Credit: Ken Ulrich, NASA


Photo Credit: Ken Ulrich, NASA

Telemetry recorded via the Servo Cylinder’s serial communication interface. The above graphs represent the azimuth actuator’s temperature and the elevation actuator’s absolute position during the five separate flights.

A2 Servo Cylinders Provide Nozzle Flap Control On Hypersonic Aircraft Engine

Hermeus is an exciting new company developing a hypersonic aircraft with the goal of revolutionizing commercial flight. Ultra Motion’s A2 Servo Cylinders control the nozzle flaps of their prototype engine during hot-fire testing.

The Servo Cylinder’s robust construction ensures reliable operation in the harshest environments and the Phase Index absolute position sensor provides rock-solid feedback in high vibration applications. The integrated BLDC control electronics are designed to produce high efficiency and extremely dynamic motion, while offering the user a variety of command protocols to facilitate integration into their system.

To see more details on the Servo Cylinder linear actuator product line including performance data and dimensions, use our online configurator here.


Servo Cylinder Actuator Ideal For UAV Applications

The Servo Cylinder is a popular choice for high reliability UAV control surface and utility linear actuator applications. The A-Series Servo Cylinder uses a brushless DC motor and contactless absolute position feedback to reduce wear and provide superior performance when compared to potentiometers and brushed DC solutions. The built-in control electronics offer a variety of communication interfaces including RC PWM, 4-20 mA in/out, ±10 VDC, RS-232, RS-422, and CANopen.

Our AM Servo Cylinder is designed to excel in harsh shock/vibe environments with IP65 dynamic and IP67 static ingress protection ratings. The D38999 receptacles provide military standard connections, and the on-board temperature, current, voltage, and humidity sensors allow for constant health monitoring of the servo actuator. The Servo Cylinder has an 8 to 36 VDC operating bus voltage, which is compliant with the majority of UAV power busses and will survive at >51 VDC.

The Servo Cylinder offers forces up to 530 lbf, strokes up to 7.75 inches, and speeds up to 14 in/s, allowing for high bandwidth control >15 Hz at small position amplitudes.

Conversions of control surfaces from rotary actuators to linear actuators can lead to increased performance and decreased cost/mass. Contact Ultra Motion Engineering to discuss your unmanned vehicle actuator requirements in detail. View Servo Cylinder performance and dimensions by using our online configurator here.

New Controller Options Including CANopen, 4-20 mA Input/Output, And More.

The Industrial Controller and CAN Controller are two new control board options now offered alongside the Classic controller integrated in all Servo Cylinder models.

The Industrial Control Board offers a 4-20 mA input and an isolated 4-20 mA output for simple and robust communication with new and existing PLC systems. The industrial control board can also be provided a ±10VDC command signal, and has an RS-422 full duplex serial connection for more reliable communication in harsh environments compared to the classic controller.

The CAN Control Board is compliant to CiA DS301 and DS402 with support for cyclic synchronous position and profile position modes, allowing for sophisticated and synchronized control of up to 127 Servo Cylinders per CAN bus. The CANopen controller has a half-duplex RS-485 serial connection for diagnostics, configuration, and field updating of the firmware.

For more information on our Servo Cylinder offerings click here, or configure your model here.

Swashplate Linear Actuator Control With Servo Cylinders

In the photo below are Ultra Motion’s A2 Servo Cylinders being shown off in a swashplate control application for a twin-rotor UAV helicopter. The A2 Servo Cylinder’s high dynamic performance, reliable operation in harsh conditions, and Phase Index absolute position feedback makes it the perfect solution for unmanned vehicle control applications. A variety of control interfaces including RS-422 serial and RC-PWM greatly simplifies interfacing the Servo Cylinder with COTS autopilots or custom avionics. 

For more information on our Servo Cylinder offerings click here, or configure your model here.

Introducing New R-Series Aerospace Actuators

Designed for the demanding shock and vibration environments of the new-space industry, the R-Series actuators from Ultra Motion leverage years of heritage in high reliability actuator design for spaceflight applications. Using Ultra Motion’s flight proven, patented Phase Index absolute position sensor, the R-Series provides high resolution absolute position feedback in the most extreme environments and with uncontested mass, economy, and power density. The R-Series actuators are the perfect solution for high reliability new-space and aerospace applications such as thrust vector control, throttle control, and fin control.

  • Dual Redundant Absolute Position Feedback
  • Forces up to 1200 lbf peak
  • Speeds up to 2.5 in/s
  • Stroke up to 3.5 inches
  • Mass < 3.0 lbm

The R-Series is a modular platform allowing for application specific requirements to easily be met, such as Mighty Mouse connectors, specific mounting arrangements, variations in force/speed, etc. Contact Ultra Motion engineering for more details.

Thrust Vector Control with Ultra Motion’s B1 Actuators

Ultra Motion’s B1 series uses best-in-class motors and robust mechanics to provide extremely high power density linear actuators. The B1 can provide continuous forces up to 500 lbf with speeds up to 2.75 in/s, or 200 lbf continuous with speeds up to 8.0 in/s. The low inertia motors offer excellent performance for applications requiring high bandwidth such as Thrust Vector Control (TVC). The B1 works well with 28 VDC power buses and is a great choice for aerospace, microsatellite launch vehicles, robotics, and scientific research applications where small form factor and high power density are critical.

Vacuum Linear Actuators

High Force Capability Vacuum Linear Actuators

Over 20 years of linear motion experience has culminated in the development of a design and assembly process that produces a high performing linear actuator rated for forces up to 500 lbf and operation within vacuums to 10^-6 Torr. Our vacuum actuators make use of special lubricants, plastics, and motors, as well as design features to eliminate virtual leaks. Ultra Motion is a trusted source of high quality vacuum linear actuators for Brookhaven National Laboratory, Sandia National Laboratories, Oak Ridge National Laboratory, and more. Contact us for more information.

Servo Cylinders in Parallel Mechanism Space Structures Robot

Six Standard (A1) Servo Cylinders were used on the NINJAR robot to help NASA meet its goals for robotic in-space assembly and manufacturing. The Servo Cylinders are mounted in a parallel kinematic arrangement to provide multiple degrees of freedom and high stiffness to the structure. The parallel manipulator allows for complete control over the structure’s shape with very high precision and repeatability.

More about the project here.

Throttle Valve Actuators

Using a triple redundant version of Ultra Motion’s Phase Index absolute position sensing technology, these actuators provide high accuracy, high bandwidth control over propellant flow in a manned spaceflight application. In order to comply with NASA-STD-5017 requirements, these actuators were designed to provide utmost reliability across extreme environmental conditions (shock, vibe, saltwater submergence, and a wide temperature range)