Sensing & Control
Position control primer
The controllers that drive modern motor-powered designs must be set up with accurate motion profiles including position, velocity, and time targets. However,...
Better by Design: Hollow-shaft encoder
Noncontact magnetic rotary encoders are hard to beat when it comes to measuring rotary motion in machinery, as they are relatively small, strong, and...
PLC versus OEM robot controls
While robot original equipment manufacturers (OEMs) each offer their own tightly integrated controllers, recent developments now enable control by a programmable...
Adaptive control in machining
If you're in the machine tool business, you know that early iterations of CNC adaptive control leave something to be desired. Most are put into a standalone...
Understanding background-suppression sensors
Photoelectric sensors with background suppression are a more evolved version of the basic diffuse sensors used on public washroom sinks to control automatic...
Servo inclinometers keep tunnel-boring machines on track
Designing ways to dig through miles of rock formations to create tunnels for transportation and other needs is one of the tallest orders faced by civil...
Noncontact motion sensors an optical advantage
Noncontact sensors are suitable for applications involving hot, wet, soft, or sensitive materials. They have been used successfully in myriad manufacturing...
Event-driven strategies enable adaptive control
Mechanical cams, once a mainstay of automation, have been largely replaced by servomotors. The reasons are easy to understand: Mechanical simplicity and...
Meeting portable design requirements with reflective encoders
Over the past few years, semiconductor companies have increasingly focused on the medical device market. Here, an emerging trend is the increase of home-managed...
Sensorless vector control
Demand for low-cost, robust motor drives has spurred increased use of sensorless vector control of induction and BLDC motors in everything from consumer...
Networks matter for optimizing exceptional machines
To simplify automation and avoid risk, many machine builders and their end customers are converging network infrastructures with EtherNet/IP for the real-time...
All about TORQUE FEEDFORWARD
Many motion applications require high accuracy during and at the completions of moves. Even with perfectly optimized PID (proportional, integral, derivative)...
Reduce downtime with vision sensors
Packaging is used across many industries and involves several stages. Each industry uses packaging to accomplish specific tasks that go well beyond simply...
Precision on the incline
A servo inclinometer is a highly sensitive transducer that converts a tilt angle into an electronic signal, and then precisely determines horizontal and...
Better by Design: Flange with feeling
Most robotics with tactile force feedback require extensive setup. Their response times can also introduce significant delays. Now, a touch-sensitive...
Selecting the right safety control architecture
The need to avoid expensive redevelopment has spurred safety-system evolution from hardwired to networked and now to integrated. Safety-rated controls...
Synchronization: Delivering tailored motion
One simple form of motion synchronization, still widely used, is an external signal trigger that causes a synchronized change in the profile for one or...
Understanding Factor 1 sensors: When and where to use
Non-contact proximity sensors can improve the ruggedness of manufacturing operations, such as metal component assembly, by replacing delicate mechanical...
Harmonic cancellation algorithms enable precision motion control
The internal model principle of control theory states that algorithms designed to perfectly reject input signals must contain a model of that input. Feedback...
Introduction to accelerometers
How do piezoelectric accelerometers vibration sensors work? The force caused by vibration or a change in motion (acceleration) causes the sensor's mass...
Linear position sensor aids Alaskan fisheries
Rick Towler of the National Oceanic and Atmospheric Administration needed help in solving an equipment challenge, which drove him to contact application...
Sliding mode control
PID control is the gold standard for most moving machines, and quite adequate in most applications that require closed-loop control. However, it's vulnerable...
BEI releases new encoders book
To learn more about correctly selecting and installing encoders, check out the newly updated Industrial Encoders for Dummies 2nd Edition from BEI Sensors,...
EtherCAT enables high-performance motion control
The EtherCAT fieldbus is quickly proliferating because of its deterministic and high-speed update rates, and ability to precisely synchronize network...
Replacing linear encoders with magnetostrictive sensors
Optical or magnetic linear encoders are traditionally used to provide position feedback in applications with frequent product changes or and sophisticated...
Servopneumatic systems
MSD: What are the advantages of servopneumatic control over other alternatives? JR Enfield: Aside from the familiar pros and cons between hydraulics and...
Advancing with machine vision
When machine vision first came onto the scene in the 1970s and 80s, the technology was generally over-promised and under-delivered. Systems were very...
Getting a grip on model-based design
Few of us are aware of the complex interactions between neural, mechanical, and sensory systems required to do something as simple as picking up a ball....
Recognizing motor temperature sensor limitations
In the first installment of this series, we discussed how two-parameter thermal models assume that the entire motor, including windings, exhibits one...
Motion control meets adaptive control
Proportional integral derivative (PID) control is the most common type of feedback control algorithm used in industry today. Because the PID algorithm...
Smart linear position sensors
A linear variable differential transformer (or LVDT) is an electromechanical transducer that reports position by converting the linear motion of an object...
Optical encoders encourage efficiency
Brushless dc (BLDC) motors are used in countless applications. Many engineers today are looking to improve the performance of their BLDC-powered systems,...
Self-powered nanosensors
A new generator and nanoscale sensors are creating possibilities for very small battery-free sensing devices that can be powered by mechanical energy...
Graphene holds promise for new sensors
Graphene, made of carbon formed into sheets just one atom in thickness, appears to be a promising base material for capturing hydrogen, according to new...
Sensor-enhanced tanks will call for help
Smart-armor vehicles may one day tell soldiers when they've been damaged and need repairs. Scientists at the U.S. Army Tank Automotive, Research, Development...
Web processing untangled
As people enjoy their morning newspapers and a hot cup of coffee, many have no clue about the critical role that web control plays in allowing them to...
Save time with reusable code
Standardized programming for automation equipment is here to stay. At the forefront is IEC 61131-3-compatible software, which generates standardized code for use on any number of controls....
Rugged encoder stands up to shock, vibration
One of the most trusted feedback devices is the tried and true rotary encoder. However, shock loads can easily break these delicate devices: The glass...
Making sense of Temperature sensing
Temperature measurement basics Tips from Omega Engineering Inc., Stamford, Conn. Temperature can be measured using a diverse array of sensors, all of...
Safety first
One of the most important aspects of industrial automation is keeping workers and equipment out of harm's way. Whether safeguarding involves physical...
Sensing for perfect packaging
Most products are shipped at one point or another, so must be securely contained to prevent breakage, spillage, and contamination. Sensors on packaging...
Maximizing efficiency with encoders
In the last installment of this two-part series, we explored how permanent-magnet brushless dc servomotors (PMBDCs) provide the highest continuous torque...
Selecting a vision system
Cognex Corp., Natick, Mass. With so many vision systems available today, identifying the most suitable for a particular application can be daunting. Vision...
Maximizing efficiency with encoders
Permanent-magnet brushless dc servomotors (PMBDCs) provide the highest continuous torque density and efficiency of any electric motors, which is why they...
Embedded control
As we covered last month, embedded motion control is operation-specific code targeted to microprocessors, FPGAs, and PLCs. As hardware becomes increasingly...
Temperature sensors
Fiber optic infrared transmitters The OS4000 series of industrial high-speed infrared transmitters measures temperatures from 392 to 2,912 F using three...
CCDs for seeing
Machine vision begins at the sensing device, and the original and most prevalent design the CCD camera or charge-coupled device recently earned its inventors...
Embedded control
Noun: Application-specific software and custom-integrated circuits specifically designed and implanted to generate commands that bring forth the best...
Color sorting quick facts
Sensing color: Many products (from automotive parts to food packaging) either have color requirements or are color-coded. Industrial color sensors are...
Considering electromagnetic delays
Magnetic actuators and sensors are used to produce and control motion. Applications include systems such as automotive anti-lock brakes, computer disk...
Sensing focus
Material science revisited Engineers: Learn about the fundamental makeup of plastics, metals, glass, and papers used for packaging and how their physics...
Connection guaranteed: Choosing the right sensor interface
During the relatively brief history of electronic motion control systems, a number of communications and networking schemes have been introduced. Not...
Position sensing primer: Direct vs. indirect load monitoring
In the field of automation, a motion control system consists of mechanical hardware coupled to a prime mover, the operation of which is governed by a...
Vision, communication, and control
Communication is key in relationships and that includes those between the operator of an inspection system, its process controls, and the vision equipment...
Picking the right language
Since the mid 1990s, substantial efforts have been made to standardize programming in all areas of industrial control. The increasing abundance of low-cost...
ODVA updates CIP Networks specs
ODVA has published new editions of specifications for the family of CIP Networks, enhancing the EtherNet/IP, DeviceNet, CompoNet, and ControlNet technologies....
Magnetostrictive sensors increase wind turbine efficiency
As part of a sustainable energy solution, wind power has demonstrated great potential to satisfy energy demands with a clean, safe, and highly efficient...
Vision-enabled feeder handles 400+ parts
Vibratory bowl conveyors provide an economical and reliable way of feeding small parts in a given orientation. However, the mechanical parts-orienting...
Vertical Hall sensing
The Hall effect is the production of a potential difference (namely, Hall voltage) across an electrical conductor in which an electric current flows in...
Top 10 tips Things to know about motion controllers
Carefully consider controller location. Just as in real estate, think location, location, location! Controller location in the overall motion system is...
Tiny encoder makes waves
Inductive encoders operate by tracking reactionary current-flow resistance (to nearby material) in one or more coils. However, there are drawbacks to...
Robotic helping hand
The Robotics and Mechanisms Laboratory (RoMeLa) of the College of Engineering at Virginia Tech, Blacksburg, Va., has developed a robotic hand that can...
Machine vision passes inspection on the production line
Vision sensors, in contrast to traditional photoelectric sensors, help machines inspect, analyze, and reject faulty parts....
Save time with displacement sensing
Long-life sensors reduce downtime LP750 linear position sensors save maintenance time and cost over more delicate potentiometers. These noncontact, long-stroke...
Web Contents
CANopen free online class Learn all about it! CANopen, based on Controller Area Network or CAN technology, is a proven serial bus that links multiple...
Introduction to PID control
Everyone uses control loops. Anytime you adjust how you do something based on previous results, you are forming your own control loop. For example, when...
Lessons in Vision
Learning the ins and outs of coupling choices and what each type has to offer will help when you face your next machine vision or optical inspection system design....
Heavy-Duty Encoders
Rotary encoders are used in a range of industrial applications, from speed monitoring on conveyor systems to position control on automated handling machines...
Magnetic sensor research holds promise
Here’s a Dagwood that is sure to make any engineer’s mouth water. Scientists at the National Institute of Standards and Technology (NIST) have discovered that a carefully built “magnetic sandwich” that combines layers of a magnetic alloy with a few nanometers of silver “spacer” has dramatically enhanced sensitivity — a 400-fold improvement in some cases. ...
Primer on rugged encoder use
You may assume that encoders are delicate, but that is not necessarily so. Here we review the construction, application, and performance characteristics of a more rugged, resilient encoder design....
New features enhance Powerlink V.1.1.0
The Ethernet Powerlink Standardization Group (EPSG) has released the Powerlink specification V.1.1.0. New features have been added by using reserved bits....
EtherCAT adds safety profile
Because today's drive profiles do not cover functional safety, the EtherCAT Technology Group (ETG) is developing a new safety drive profile to close the...
Motion controllers aid space exploration
Exploring the deepest corners of space depends on savvy astronomers with access to the right tools, not the least of which are powerful telescopes. A...
Letting go: Angle sensors
Most rotary position sensors have some effect on the motion they aim to measure. They also tend to complicate design, requiring shaft-to-shaft connections...
Thin sensor gets the skinny on angles
For countless industrial products that have evolved over time, smaller, better, and less expensive is the name of the game. After designing and manufacturing...
Proximity sensing
HOW DOES THE CHOICE OF PROXIMITY SENSORS AFFECT THE DESIGN AND OPERATION OF MOTION-CENTRIC AUTOMATION SYSTEMS? Alex Baumer: Proximity sensors, through...
Stepping off the plane
Non-Cartesian actuators are improving applications where they weren’t even feasible before...
Golden seals
New gears pay off for glassware maker...
Robots show their sensitive side
Knowing some force-torque sensor system basics could boost your metallic friend’s performance...
Signed, sealed, delivered
Scanning platform demands simplicity and strength from its control...
Handle with care
Take care of your bearings and they’ll take care of you...
Selecting nonfriction stopping methods
Selecting the best method for controlling how a motor stops maximizes machine productivity. This article will help you evaluate the numerious nonfriction methods...
Low-EMI motion control improves accuracy
Electrical noise from motion control components can cause erroneous readings in a system that tests disks for computer hard drives. Here is how engineers minimized the EMI and eliminated these errors...
Rotary motion sensor combines long life with low cost
Until now, users had to choose between economical optical encoders and durable resolvers for sensing rotary motion. But, a new type of resolver reportedly offers the best of both worlds: durability and low cost...
Electrical systems lead the motion control race
Electromechanical motion control systems have competed with hydraulic systems for years. But environmental factors, improved performance, and even physics have pushed electrical control into the forefront...
Replacing line-shaft drives with servos improves productivity and quality
Converting a single-axis, high-horsepower drive to multiaxis, servo-controlled operation is a cost-effective way to achieve higher productivity and quality, at lower operating costs...
Digital control opens options for packagers
Not long ago, packagers’ debates centered on whether or not to use servos. Digital technology, however, is pushing packagers beyond the servomotor decision...
Brushing up on motion architectures
A brief overview of the different motion control architectures, and their advantages and limitations, can help designers find the best solution for a particular job...
Whats and whys of control loops
In motion control applications, you frequently hear all sorts of loops -- open, closed, current, torque, speed, voltage, and so on. Here, we define and explain these terms...
Caring for water-soaked controllers
PT devices wet from flood waters need not always be junked. This article gives pointers for rejuvenating motor starters and adjustable-speed drive controllers. This is especially timely for those in the Midwest...
Photoelectric sensors meet new challenges
Extra-sensory perception: Recent advances in photoelectric technology have produced solutions to sensing problems that were thought difficult — or even impossible — to solve with photoelectric sensors...
Catching shaft torque data on the fly
As the pressure to control manufacturing equipment grows, engineers increasingly rely on torque data from drive shafts as an indicator of machine condition. Wireless measurement techniques are making it easier to pluck this data from spinning shafts...
Communications standard for new era of control
A battle for standardization of a new communication bus is underway. Meanwhile, its potential benefits are still emerging...
The basics of motion control: Part 1
Here are easy-to-follow equations for determining drive mechanics, friction and inertia, for any electromechanical positioning application. Then, using this information, a following article will show you how to determine motor and control requirements...
Integrating motion control systems
Recently, programmable logic control manufacturers introduced device-level buses (networks) to integrate sensors and low-level control devices with various automation systems including motion control systems...
Fuzzy logic: a new tool for the control engineer's toolbox
A control method that mimics the human mind solves difficult control problems by making decisions based on imprecise data...
Selecting the right servo requires choosing the right communication platform
Servos are inherently capable of delivering high performance. To maximize that capability requires selecting the best communication platform...
Smart photoelectric sensors bring new capabilities to the factory floor
Many photoelectric sensors use built-in intelligence to optimize their adjustments and improve reliability. Diagnostics and networking capabilities come with the package too...
Synchronizer ends jam-up on cookie line
Wagon Wheel cookies are rolling smoothly off the production line thanks to a new electronic synchronizing controller that solved a long-standing conveyor jam-up problem...
More versatile networks boost motion control capabilities
Producer-consumer networks perform more functions and do them more quickly. This innovative concept in network communications may herald the next generation of control networking...
