Motion Control

An Inside Look at Electromechanical Power-Off Braking Options

Making the right choice between spring set and permanent magnet brakes can impact safety, durability, maintenance, and performance.

Power-off brakes are designed to hold or stop motion in the absence of power. Adding an electrical current releases the brake, freeing the load for motion. Given the safety ramifications of keeping a system locked in place until it is powered up, motion control system designers tend to specify power-off brakes more often than power-on brakes. There are, however, two different failsafe brake technologies: one uses compression springs to hold its load in place, and the other uses permanent magnets. Each has specific strengths and weaknesses, and knowing the difference can impact safety, durability, cost, and performance.

Posted in: Articles, Motion Control, Electronic brake controls, Springs, Magnetic materials

A Method for Accurate Load/Position Control of Rigidly Coupled Electromechanical Actuators

NASA has developed a technique designed to prevent cross-coupling in systems where two or more linear electro-mechanical actuators (EMA) are rigidly connected and are in danger of becoming cross-coupled. In such systems where the linked EMAs are commanded to achieve two distinct goals, such as position and load control, control problems often arise — especially at higher load and linear velocity levels. Both position and load control become inaccurate and in certain situations, stability of the overall system may be compromised. The NASA-developed approach mitigates the problem and achieves both accurate position following and desired load levels between the two (or more) actuators.

Posted in: Briefs, Mechanical Components, Mechanics, Positioning Equipment, Electronic control systems, Electronic equipment, Sensors and actuators

Simplified Machine Design Approach for Optimal Servomotor Control

An often asked question from industrial machine builders or integrators is how they can effectively design or implement the conversion of a machine with servo technology to meet performance expectations. This is a specialized task filled with layers of complexity that can prove difficult to execute, even when the scope of work is fully understood.

Posted in: Articles, Motion Control, Design processes, Sensors and actuators, Industrial vehicles and equipment

Robots and Humans - Let the Collaboration Begin

A collaborative robot is essentially an industrial robot with additional safety capabilities. These safety features include:

Safety-rated monitored stop (zero speed limiting) Speed and separation monitoring (limiting) Hand-guiding Power and force limiting (PFL)
Posted in: Articles, Motion Control, Human machine interface (HMI), Robotics

Optimizing Drive Systems for Energy Savings

Energy savings are an extremely important topic in virtually every segment of industry today. In general, the largest consumer of power in a converting line or machine is the drive system. As energy costs continue to increase and energy conservation becomes a greater priority, are there technologies or methods that can be implemented to reduce the energy consumption on converting machinery?

Posted in: Articles, Motion Control, Energy consumption, Vehicle drive systems

Choosing the Right Potentiometer for Reliable Sensing

In today’s market, there are a variety of available types of position sensing systems. It is important to compare unique features to application needs in order to find the best fit.

A potentiometer sensor is an electromechanical component that consists of a resistor where the voltage divider value can be measured at any position by means of sliding contacts between the applied voltage values. Physically, a potentiometer consists, at a minimum, of a resistance track, a collector track, and a sliding contact that can be moved along the resistance track by means of mechanics (Figure 1). The movement of the sliding contact can be rotatory (angle) or translational (path).

Posted in: Articles, Motion Control, Sensors and actuators, Test equipment and instrumentation

Imitative Robotic Control: The Puppet Master

Automated systems can have a hard time completing complex tasks in a timely manner. When controlling a robot outside autonomous mode, a good control device needs to give the user full control of the system while enabling the mission to be completed in a quick, accurate, and efficient manner.

Posted in: Articles, Motion Control, Robotics

Choosing the Right Drive Technology

Coming up with the right drive technology for an application often depends on the options available. Here are five of the most common drive configurations being used today, along with their benefits and drawbacks.

Although there are a number of variations of drive technologies for motion applications, there are a few that are used for the majority of systems being built today. These most common drives do take a bit of understanding before applying.

Posted in: Articles, Motion Control, Electronic control systems, Vehicle drive systems

Reasons for Turning to Slotless DC Motor Technology

When first introduced, brushless DC motors, despite their many advantages, were cast as a costly alternative to brush-commutated motors, and were typically only specified for low-power applications where long life was the primary desired requirement. Without the mechanical brush-commutator mechanism that would wear and eventually result in motor failure, brushless motors could be relied upon to deliver performance over time. As for other advantages, conventional wisdom held that brushless motors provide high speed and fast acceleration, generate less audible noise and electromagnetic interference, and require low maintenance. Brush-commutated motors, on the other hand, would afford smooth operation and greater economy.

Posted in: Articles, Motion Control, Automation, Electric motors

What Engineers and Customers Need from a Motion Control System

In the automation industry, engineers strive every day to advance their process and products. Engineers have to select components, learn and use many tools to construct their automation systems, and support the systems in production. More importantly, to be successful and competitive, they are faced with many challenges to achieve higher throughput and ease of use within budget and time limitations.

Posted in: Articles, Motion Control, Automation, Production engineering

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