Motion Control

NASA's Hot 100 Technologies: Mechanical & Fluid Systems

Spring Joint Package with Overstrain Sensor

This flexible joint provides two degrees of freedom and a tremendous amount of compliance. The overstrain sensor joint has a passive and restoring force that allows the joint to return to a default position, and is also proportional to the amount of lateral deflection the spring has undergone; this allows the OS sensor joint to be used in many of the under-constrained situations that cause universal joints to lock up.

Posted in: Articles, Techs for License, Fluid Handling, Motors & Drives
Read More >>

Analyzing 6-Pulse Drive Harmonic Mitigation Techniques for Industrial Automation

Contemporary industrial automation control systems are employing variable frequency drives (VFDs) in ever-increasing numbers. VFDs give control engineers flexibility to precisely regulate the speed and torque of motors in a wide array of applications. The proliferation of these VFDs has brought increased attention to harmonic distortion created by these drives and their effects on the power system. A standard-pulse drive with no built-in harmonic mitigation controls may interfere with neighboring equipment, reduce equipment life, and create a serious negative impact on the quality of utility power. Looking at the theory of operation for the following harmonic mitigation techniques and their typical performance levels may help take the guesswork out of harmonic reduction for these power systems.

Posted in: Articles, Motion Control, Automation
Read More >>

Reliable Locking in High-Vibration Environments

Today’s PCB plug-in connectors must accommodate many trends, including increasing miniaturization, rising levels of performance of electronic components, and growing complexity in machine and system engineering.

Posted in: Articles, Motion Control, Connectors and terminals, Electronic equipment, Vibration
Read More >>

Selecting the Proper Motor for Linear Motion Applications

Linear motion systems are found inside countless machines including precision laser cutting systems, laboratory automation equipment, semiconductor fabrication machines, CNC machines, factory automation, and many others too numerous to list. They range from the relatively simple such as an inexpensive seat actuator in a passenger vehicle, to a complex, multi-axis coordinate system complete with control and drive electronics for closed-loop positioning. No matter how simple or complex the linear motion system, at the most basic level, they all have one thing in common: moving a load through a linear distance in a specific amount of time.

Posted in: Articles, Motion Control, Automation, Cutting, Fabrication, Manufacturing equipment and machinery
Read More >>

Design Considerations for Gearmotors in Long-Life Applications

At first glance, the photo at the top is not appealing to any market — a pallet full of old gearmotors is not something one wants to think about after purchasing the necessary gearmotor/motor for their application. But think of it this way instead: these gearmotors were removed from their installation for a refurbishment project after being in service for 30 years. Sandia National Laboratories placed these gearmotors into service in their Heliostat Field in New Mexico in the 1970s. The gearmotors were used to position solar reflectors to concentrate light from all of the individual panels towards one point at the top of a tower. After 30 years, Sandia decided to upgrade the field with a new control system, and they decided to replace the still-operating gearmotors at the same time.

Posted in: Articles, Motion Control, Life cycle analysis
Read More >>

Redundant Sensors Improve Precision and Reliability

Some machine processes, such as presses, can require extreme accuracy in applying and holding force on an object. A popular way to measure force is via load cells. But what do you do when the accuracy required by a particular application is higher than that guaranteed by the load cell manufacturer?

Posted in: Articles, Motion Control, Sensors and actuators
Read More >>

High-Temperature Actuators for Aircraft Propulsion Systems

Future “more electric aircraft” (MEA) will require electric actuation systems for control surfaces and engine controls. Electric motors, drive electronics, and mechanisms are essential elements of aircraft actuation in MEAs that incorporate Electro-Magnetic Actuators (EMAs). High-temperature environments experienced in aircraft applications place demands on actuator components, materials, and insulation systems that dictate the use of new technologies and materials.

Posted in: Articles, Motion Control, Flight control actuators, Thermal management, Heat resistant materials, Electric motors
Read More >>

Designing a Multi-Segmented Robot for Hull Climbing

The Multi-segmented Magnetic Ro bot (MSMR) project addresses a capability gap in the intelligence, surveillance, and reconnaissance needs of the U.S. Navy visit, board, search, and seizure (VBSS); Navy SEALs; and Marine Force Reconnaissance teams. A segmented robotic platform with magnetic wheels and a minimal acoustic signature was developed that can navigate the hull, tanks, and passageways of a ship. The goal was to provide effective climbing and turning ability over and within a ferrous hull that typically features plumbing, protrusions, and indentations such as weld seams where hull plating meets. Such a robot will be able to climb the hull of a ship, provide covert perch-and-stare surveillance of the deck area, and wirelessly transmit audio/video before a search team boards. The technology is also promising for inspection of tanks, and dangerous or hard-to-reach passageways and voids in maritime vessels.

Posted in: Articles, Motion Control, Robotics, Inspections, Marine vehicles and equipment, Military vehicles and equipment
Read More >>

Moving Magnet Voice Coil Actuators Offer Controllable Movement for High-Duty-Cycle Applications

There are two types of voice coil actuators: moving coil and moving magnet. The materials of construction are similar, since they both use rare earth magnets, steel, copper wire, and basic insulation materials. There is a tendency to want to say one type is better suited for certain applications; however, there are many different sizes and shapes of voice coil actuators, making it difficult to make blanket statements about which type of actuator works better, and where.

Posted in: Articles, Motion Control, Sensors and actuators, Copper, Insulation, Steel
Read More >>

Optimizing Closed-Loop Control in Hydraulic Motion

Performing closed-loop control of hydraulic servo systems is often more challenging than controlling servomotor systems. The main reason is that hydraulic systems use compressible oil to move the actuator. Because of this, a hydraulic system can be modeled as a mass between two springs, where the piston and the load is the mass, and the oil on both sides of the piston represents the two springs. In contrast, servomotor systems are easier to control because there is basically only the inertia of the motor and the connected load to be dealt with.

Posted in: Articles, Motion Control, Vibration, Hydraulic systems
Read More >>

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.