Motion control, a subset of automation, focuses on the precise controlled movement of individual parts of a machine. This technology finds extensive applications in various fields, particularly in production lines, where precision, efficiency, and power are critical. Through a motion control system not only can a machine achieve the desired movement, but it can also ensure a smooth stop once the task is completed.
Now, let’s explore the realm of automation through motion control and discover the various components involved, as well as the exciting advancements that are revolutionizing the field of motion control.
Components of Motion Control System
A motion control system controls one or more of a machine’s position, velocity, force, and/or pressure.
There are two main types of motion control systems: open-loop systems and closed-loop systems. The primary difference between the two is that open-loop systems don’t use feedback, while closed-loop systems do.
Motion control systems often include the following elements:
1. Motion Controllers
Motion controllers are the brains of motion control systems that calculate and generate the commands that navigate the machine’s movement. They send these commands to the rest of the system and, based on input, change their directives to fit the system’s requirements.
Motion controllers employ a variety of algorithms such as interpolators, control loops, and step generators, to calculate the precise movement of the machine based on each segment or set point.
2. Drives
Motion controllers send commands to drives in the form of low-voltage signals. These drives use these signals to communicate high-power current and voltage quantities to the rest of the motion control system. The different types of drives are:
- Digital drives
- Analog drives
- Linear drives
- Switching drives
- Stepper or Microstepping drives
- Servo drives:
3. Motors
Motors transform electrical energy into mechanical energy, powering the motion control system. There are numerous types of motors as follows:
- DC motors: These are also referred to as brushed or brush-type motors. To achieve torque, they use carbon brushes and a mechanical communicator. They require simpler drivers, are more expensive to maintain, and are often larger than brushless motors.
- Brushless Servo Motors: Brushless motors, as the name suggests, do not require brushes. They achieve rotation instead of an electrical connection from the drive. They offer a lot of acceleration and torque and require very little maintenance.
- Linear Servo Motors: Linear motors use linear motion instead of rotary motion. Electromagnetic forces generate propulsion, obviating the necessity for rotary to linear conversion. These motors are quick, precise, and responsive, with no backlashes and no need for maintenance. They also require more bandwidth and have a greater footprint.
- Stepper motors: These are DC motors with several coils organized in phases. Each phase is activated sequentially, spinning the motor one step at a time. They move in precise, repetitive steps, allowing for precision placement, control of speed, and low-speed torque.
4. Feedback Devices
In closed-loop systems, motion controllers use feedback sensors to make necessary system adjustments, ensuring that the correct commands are given at all times.
The most common type of feedback device is an encoder (linear or rotary), which is an electromagnetic device that delivers position, velocity, and direction-related information. On the other hand, absolute encoders can directly track positioning with a variety of distinct values (serial, voltage, binary count, and so on).
Top Innovations in Motion Control
As the technologies advance, the productivity of the associated equipment increases. Here are four examples of new motion control products with their notable features:
1. EHS Series: Electrohydraulic Pump Drive Motors of Allied Motion
Electrohydraulic pumps are critical components of truck and bus power steering systems. New York-based Allied Motion supplies pump motors that directly propel the electronic parts on commercial vehicles with its EHS Series of brushless drive motors that are designed for electrohydraulic pumps. As opposed to fully hydraulic solutions, the EHS Series’ electric power steering solutions have significant fuel efficiency benefits with greater design freedom and are available with integrated hydraulic pumps.
The EHS Series pump motors allow the motor to function as an intelligent node in networks of other modern vehicles. Moreover, these pump motors have excellent durability and long lifespans even in harsh conditions. As such, buyers can look forward to reduced overall maintenance and repair expenses compared to all-hydraulic options.
The products in the EHS Series are primarily meant for large vehicles such as buses and heavy trucks. These pump motors also find usage in agricultural equipment and lift trucks with hydraulic steering.
2. POSITAL IXARC’s Magnetic Absolute Encoders
Magnetic encoders are used in motion control applications for converting angles or other positional data into analog or digital signals. They gather data to send to encoder engines, which deliver the appropriate signals to the motion control application.
The new magnetic absolute encoders from POSITAL’s IXARC range include CANopen interfaces that offer adjustable connection caps, making device configuration and troubleshooting easier.
CANopen is a high-level communication protocol and device specification used in automation embedded systems. CANopen interfaces include smaller connection caps with three rotary switches and greater shock and vibration resistance compared to prior versions of IXARC magnetic controllers.
A small screwdriver employed for installation can define the node ID and baud rate, which refers to the communication speed across a data channel. The encoder’s eight screw terminals on the back enable cable installation. Furthermore, diagnostic LEDs on the back of the cap display the device and network status, allowing for quick installation and debugging of these Ethernet-compatible devices.
3. CoRe: Flow Control Series of Solenoid Valves by Marotta
Marotta and its specialty components have played a role in over 50 space programs since the 1940s. A solenoid valve regulates the flow of gases and liquids in the device.
Marotta provides a line of pilot-operated/direct-acting solenoid valves. The pilot-operated kind is controlled by the differential pressure of the medium over the valve ports. That is, they require pressure to remain closed. Direct-acting solenoid valves, on the other hand, remain closed even when no force is applied.
The CoRe Flow Control Series includes six novel options, all intended for commercial space launch vehicle applications. These components are durable and high-performance while being reasonably priced.
4. ABB’s OmniCore: Digital Robot Controllers
Digital robot controllers are becoming increasingly popular. In the motion control setting, these robots accept inputs and adjust their outputs accordingly. It enables connected robotics equipment to perform in a precise and measured manner.
ABB’s new range of digital robot controllers operates in an industrial setting that requires 24×7 uninterrupted operation to satisfy the needs of today’s manufacturers. These robots are highly customizable, have excellent path accuracy, and have a 50% lower footprint than competing options. As a result, they can fit into small spaces.
ABB’s ‘Ability’ platform is used in the OmniCore controller solutions. It helps with equipment administration, remote monitoring, and other tasks.
The platform includes the company’s SafeMove2 technology, which transforms any networked industrial robot into a collaborative model that works safely and quickly among humans.
What Does the Future Hold for Motion Control?
The development of autonomous vehicles and self-driving cars is driving the need for advanced vehicle motion control technologies. Additionally, the proliferation of motion control technology in gaming and other entertainment industries suggests that motion control will continue to play an important role in various aspects of life. The future of motion control appears bright on account of advances in other technologies such as artificial intelligence, automation, and smart sensors.