Understanding Servo Drives

For those who do not know, servo drives are electronic amplifiers used to power-drive servomechanisms. In other words, servo drives work by accepting signals from a control system. After which, it then amplifies the signal and conveys the electric current to a servo monitor so that it would produce a motion that is relative to the given command signal. Usually, command signals represent a preferred velocity, although it can also be a desired position or torque. The servo motor’s definite status is reported back to servo drives through a sensor that is attached to it. Servo drives will then evaluate the actual status of the motor with the commanded motor status.

Contribution of servo drives to businesses

Servo drives and servo systems, as a whole, can be used in computer numerical control (CNC) machining, automation of factories, robotics, and many more. Because of this, when companies are equipped with this state of the art system, there will be significant benefits to the operations of the company. To start with, efficiency will greatly increase since operations are done in an automated manner. Second, servo drives are also cost-efficient. Thus, this kind of system can also help in lessening an industry’s cost of operations. Third, compared to the usual alternating current (AC) motors and direct current (DC) motors, servos are more accurate when it comes to commanded motions. This is because servo drives are built with motor feedback which also detects any unwanted motions. Furthermore, unlike the usual alternating current motors and direct current motors, servo drives have better life cycle.

Versatility and Flexibility through Servo Systems

Since servo systems function better than the typical AC and DC motors, companies that use servos are able to enjoy advantages like being versatile and flexible when it comes to their operations. This is because servos are considered to be the next-generation high performance drives. Servo systems are characterized by its highly innovated software and hardware designs that are capable of delivering better performance.

AC and DC Servo Drives

As mentioned earlier, typical alternating current drives and direct current drives are now things of the past. Through servo systems, industries can now enjoy the benefits of the new and improved ACservo drives and DC servo drives which are more accurate in translating commands, perform better, have better life cycles, and a lot more. Examples of the latest alternating current servo drives include CD Series 5 and PPB direct PWM products.

Servo Drives: Final Verdict

Indeed, through the innovation of servo drives, motor operations of industries are now brought to a new level. Through this system, industries can now enjoy benefits like better performance, cost-efficiency, operational efficiency, precise and accurate work and a lot more.

Helping Increase Safety with Computerized Motors

Car manufacturers and assembly lines have long relied on servo motors in order to increase productivity and consistency on the line. Now, these same AC servo motors are helping to increase safety levels both for the employees of the plants and for those who are driving the vehicles. Technicians have realized the increased parameter options allows for more control over the finished product. This means less variation so that the pieces fit together in a way making them more stable than ever before and increasing the overall safety of the vehicle.

The AC servo motors that control the line help prevent overheating. This type of condition can cause fires, meltdowns and other dangerous situations for those who are monitoring the line. By using a mechanism that makes adjustments immediately, like a servo, the problem never has a chance to develop. It takes much less time to make a correction from the beginning than undoing a problem scenario has blown out of control. Think of it along the lines of laying a drop cloth down when you are painting or trying to clean up the paint off the ground after you are done. One is a simple clean up job and the other is a protracted process.

For the output of the product, because a servo motor can monitor things so closely there are fewer problems with the end product. When bolts and pieces do not meet up exactly, vibrations and other processes can cause things to wiggle loose. This factor often results in tires falling off, seat belts failing, pieces of the engine getting knocked out or other disastrous scenarios. By ensuring everything is exactly uniform, there is less chance of this type of problem. Basically it was the next logical step in the development of motorized vehicle development and the assembly line. The companies had maxed out what could be done with just humans and found a way to utilize the computerized systems in order to increase safety and productivity at the same time. Helping to make life safer is a great side benefit of computerized advances.

AC Servo Drives

AC servo drives use alternating current to match and meet the varying industrial status and rise up to any occasion to meet machine deviations. AC motors have an outside stationary stator which has coils to produce a rotating magnetic field with the alternating current and an interior rotor which attached to this external shaft creating the precise torque for the machine function.

AC servo drives are widely used in industrial settings. They can be single phased or poly-phased (two-phased, three-phased or hysteresis synchronous). The single phase induction AC servo motor is connected to a single voltage line while the others take up more than one as their nomenclatures suggest. Of all these, the two phase ones most common as servo systems.

The two phase AC motors are more sensitive to voltage fluctuations and changes in the control system. They successfully create a rotating magnetic field. AC servo drives therefore offers better control with high torque, high speed and better application of velocity control.  Their high ability to start power allows lower levels of overall power to be transmitted. The alternating power function determines how much power is needed by the system and gives off only that amount thus managing power efficiency and industrial automation control superbly.

AC servo drives are intrinsic to electronic assembly because they can fill in gaps with alternating current and thereby ensure smooth uninterrupted flow of industrial performance. They come with interactive magnetic fields – the wound and the electrified which are used to synchronize with the frequency of the alternating current. An integrated feedback device that continuously monitors the shaft motion, and in combination with a servo drive regulates the commanded motion very precisely.

Benefits of the AC servo drives –

·         Lower maintenance

·         High starting power potential

·         Less wastage of power

·         Accurate performance for machines

·         Cost effective

·         Provides better industrial automation control for better turnover

Applications of AC servo drives –

·         Electric clocks and timer motors in appliances.

·         Home usage in appliances refrigerator, air conditioners, washing machines, dryers and fans.

·         Industrial usage is manifested in CNC machining, in electronic assembly, in factory automation and very widely in robotics industry.

More and more industries are switching to AC servo drives so that they can perform better, save assembly line costs, create a more economical process all the while making sure that there is optimum energy saving without compromising the level of performance and industrial automation control.

Benefits of Pick and Place Servo Drives

 In an age of rapid industrialization and intense competition, manufacturers simply cannot afford to compromise on the speed and accuracy of the machines and assembly lines in their production units. Prudence thus lies in investing in servo systems that speed up the functions on the assembly line front and also add to the precision of the operations. Herein stems the importance of pick and place robots in an assembly process. These systems are commonly found in industrial automation processes and are used to sort components and place them in their appropriate slots in the line.

Pick and place servo drives systems are some of the most expensive components in an industrial assembly line but manufacturers usually do not hesitate to invest in these because of the advantages that installing one such system affords. The following are some of the benefits of pick and place systems:

• Speed: Pick and place robotic systems, by automating processes, speed up cycle times. This in turn, leads to faster production, a key requirement for businesses to prosper in a 24X7 world. A servo controlled pick and place system is especially considered matchless on this front.

• Precision: Pick and place systems are almost 100% accurate in their operations, much more than a human being can ever be. When quality is the key to retaining customers, this feature ensures that manufacturing units engaging pick and place systems are consistently able to outsmart competition.

• Reliability: Powered by servo control, pick and place systems, when in top-notch shape, can work round the clock on all days of the week. This enables a manufacturing unit to churn out products in almost no time at all. This in turn, leads to considerable revenues.

• Flexibility: A slight tweak in the programming controls or a few twists and turns of the tools are all that is needed to equip a pick and place system with the capability to deal with multiple applications. This flexibility makes installing such a system extremely cost-effective.

• Cost-Effectiveness: The afore-mentioned features combine to lend a high degree of cost-effectiveness to such systems. Cost effectiveness also accrues from the fact that pick and place systems empower businesses to take up orders in bulk and thus aid business expansion and also reap the benefits of large-scale production.

Advances in technology in recent times complemented by a drop in prices, have made pick and place systems more affordable. It is thus possible for even small-scale production unit owners to own such a servo control system and reap its benefits.

AC Servo Drives – The Present Industrial Requirement

Servo drives are specially made electronic amplifier that is used to boost or run electric servo mechanisms. All the feedback signals that come from the servo mechanisms are actually monitored by the servo drives. A servo drive continuously adjusts even the smallest deviation from the normal behavior.

It should be known that the main function of a servo drive is to receive the command signals from the control system and then amplify it so as to transmit the electric current to the servo motor. This is done to produce motion that is proportional to command signal. In general, the command signal signifies a preferred velocity but it can also signify a desired torque if and when required. 

The servo drive gets the feedback of the actual status of servo motor control from the servo motor’s attached sensor. The actual status of the motor is then compared with the commanded motor status by the servo drive. The servo drive alters the voltage frequency of the motor in order to correct any small deviation from the desired commanded status. 

The servo motor control rotates at a speed which closely matches the velocity signal that is being received from the control system by the servo drive. There are several parameters like derivative gain, proportional gain and feedback requires proper adjustment so as to achieve the desired performance. This process of adjusting of the parameters is known as performance tuning.   
     

With the advancement in the technology of the microprocessor units there has been a constant growth of cost effective solution and development of a permanent magnet manufacturing technology for the servo motors. There has been a great improvement in the technological development of the high performance and high power semi conductor power devices. Thus, AC servo drives, AC servo motor has now become the basic technology for achieving automation control system in the present industrial scenario. 

AC servo drivers bring in the newest high speed DSP in order to meet the varied requirements of your high speed and high precision control system. The latest AC servo drives have a lot better dynamic feature and stability that the convention PI controls systems of yester years.  

Today’s AC Servo drives includes analogue apparatus within the control loop of a servo motor that helps to minimize the energy consumption and ensures maximum output. They assist in changing frequency of the AC voltage which is received by the motor with the use of electronic devices.

AC Servo Drives

Mechanisms belonging to the range of motion electronic products, AC servo drives operate on alternate voltage patterns. As electronic amplifiers, they serve to power electric servo motors that similarly operate on alternate voltage pattern.

As special electronic amplifiers they A) monitor control feedback signals received from motors. B) According to feedback signals received they make necessary adjustments. C) They form a part of a dynamical system.

The function of AC servo drives is guided by the ‘control theory’, which is a sub part of Physics and Mathematics. According to this theory, A) A controller, manipulates the input to a system. B) This manipulation is geared to achieving the desired effect on the output. C) Output variables follow a reference of time. A.C servo drives act as controllers or A.C electrical amplifiers.


"Motion theory" also controls the functioning of servo drives. As special electronic mechanisms, they control the velocity of mechanisms. After receiving a command signal from a control system geared to A.C voltage, they amplify such signals and after due amplification, they transmit electric current to a system. Automatically, the electric current transmitted will be proportionate to the received command signal.

The servo motor with an attached velocity sensor does the needful work of reporting the motor’s actual velocity back to servo drive. After a due comparison of motor’s actual velocity with the command velocity, AC servo drives contribute to altering the due voltage frequency. Thus any error in voltage frequency is corrected by A.C servo drives. Usually servo motors rotate at a velocity matching the control signal. Servo motor control ensures the due matching leading to the establishment with proper configuration and tuning- which is a combination of proportional and derivative gain.

A.C servo drives are not only easily available, but they are also compatible with different variety of motors. Use of A.C servo drives has manifold advantages. Forming an integral part of the servo system their additional feedback serves to detect unwanted motion. They usually accurately assess the commanded motion. Moreover they are better adjusted to changing speed, with a better life span; giving effective durability to a system.

Servo drives are generally of two types. 1) Digital servo deals with discreet tracking of signals. 2) Analog deals with continuous tracking of signals.  Servo drives which form an integral part of the servo system have an enormous role to play in industries involved with robotics, automation and any other kind reliant on motion theory.

Custom Servo drives - an Overview

Custom servo drives are a kind of cost effective and optimized servo drive which are designed according to the customers applications to meet their needs of form, cost, fit and function specifications. Mostly known as the “special electronic amplifiers”, a custom or standard servo drive is commonly used to control the motors of the electric servo.

Over the decades, the technology of servo controls has changed a lot with its size, rotational speed, and torque. Custom servo drives are one of the major developments in the world of servo drives. The custom servo is almost similar to its digital counterparts. They have the same gears, motors and cases and most importantly they have a “Feedback potentiometer or Pot” like the digitals.

Designs of the custom servo drives:

• Optimized packaging- form factors, special connectors
• Multi Axis- two and three axis packages and systems based on racks
• Power Ratings-voltage and custom current ratings
• Java Beans-“fill in the blanks” standard indexer functions
• Enhanced Firmware-standard compensation filters
• Performance Edge-temperature compensation, low noise
• Feedback-special encoders

Classification of custom servo drives:

Custom servo drives can be classified based on the shapes, electric circuitry, sizes, type of feedback, input power variations, command and performance signal. Every factor has a great value in making the decision of the actual price of the custom servo drive.

Usage of custom servo drives:

Nowadays, custom servo drives are usually used in various industries like packaging, robotics, textile, factories of CNC machining and printing. With the increasing usage, the need of custom servo controls has increased a lot.

Advantages of using custom servo drives:

• Power saving ability:  In a custom servo drive, no power is sent to the servo motor when the car is idle. When the signal of moving the car is received, the power is sent to the servo motor up to a maximum voltage and then the servo responses. The servo doesn’t responses until the power reaches the maximum. This helps to save the excess power from being wasted. 
• Immense Standing Torque: The quotients of the standing torques of the custom servo drives are very high.
•  Monitoring: The custom servo drive is able to monitor the feedback signals from the motors by making some subsequent adjustments.

It is a fact that custom servo drives are very essential for the industry which totally depends on the motion control. So, to grow your industry, switch on to custom servo drives.

Servo Drives – Facts and Features

Servo drives have revolutionized the way key industrial applications run today. Digital servo has taken the mechanism of motion control to a new height where it amplifies the signals and makes mechanical output faster and more effective.

Benefits of servo drives -

• Higher and more dynamic response
• Reliable
• Cost effective
• Higher productivity and performance
• Accurate output
• Flexibility that can share technologies across diverse types of machines
• Higher safety and hygiene protocols
• User friendly interface that is easily PC adapted for fluid control
• Comprehensive programmed software for easier manipulation
• Higher feedback and report system makes for stronger output functions
• Super speed internal and external communication system enabled across multiple platforms
• Regular and quick updates of speed, position and current status leading to machine precision
• Reduced errors in tracking
• High precision supply of current while saving energy
• Interface for analog reading to use older machines

Digital servo drives function across servomotors like torque, asynchronous and linear motors and the brushless PM AC motors due to high end modular design. Based on 32- bit 400MHz microprocessor, it can used as effectively as a singular product as in a comprehensive system. It can ease the way your machine performs this providing higher output or aid in the machine design. Effective servo drive functions offer complete digital control and manipulation of brushless servo motors, delivers increased current and velocity leading to high precision performance that is the need of the hour across industries. Multi level interfaces, effective feedback system and superior controllers.

Leading vendors design and offer different kinds of servo drives –

• Servo drives that can control low power application for smaller machines requiring less than 1.5 kw. This effectively reduces design time and commission time, as well as provide layouts and CAD drawings.
• Digital servo drives that can handle multiple applications through single-axis motion control. They have inherent dynamic brakes, velocity observer, tuner and suppression algorithms to provide more cost effective motion control output.
• A multi-axis servo drive can helps in decreasing engineering time by helping effectively in networking, programming and operations. Adds greater flexibility and handles global voltage volume needs.
• Some come with high end safety options and flexible designs that can function on multiple levels and interfaces.
• EtherNet Servo Drives standardize the entire communication network leading to faster commissioning and startups, precise and easier configuration. Allows effective control integration with high speed connectivity.
• Some have troubleshooting options built in them, with automatic capacity of motor recognition.

Important Facts behind Servo Motion Controller

Servo drives have been an integral part of efficient output ever since they came into being. The servo motion controller has further enhanced the way industries can work, with precision management of position, velocity and movement and therefore aligning the entire process uniformly. 

The key industries benefiting from servo control system include:

• Assembly line units
• Industrial Machines
• Packaging industries
• Semiconductor production facilities
• Textile mills
• Printing houses
• High end video game industries
• Robot manufacturing
• Medical Equipments

The various servo drive products range from the simple servo motors, DC motors, servo drives, gears, linear motion components and actuators, linear ball and lead screws, linear and rotary brushless servo motors among others. The servo motion controller enhances velocity and position of these machines and their electric motors for effective and efficient output. 

The wires in servo motion control:  The 3 wire connector –

1. One supplies five to six volts of positive charge (DC)
2. The second one serves as voltage ground
3. The third wire acts as the signal wire through which the receiver responds

Servo motion controller not only enhances machine performance but also anticipates mishaps. The in-built mechanism can read slightest of the errors thus acting as a checkpoint for your machine’s efficiency. 

Benefits of servo motion control –

•             Accelerate system development

•             Increase system bandwidth

•             Control velocity, forces and pressures

•             Monitor feedback signals

•             Adjust motion to avoid deviations

•             Managing point-to-point positions

•             Quicker response times leading to higher machine output

•             Electronic gearing

•             Address mechanical needs of improving the transient response timings

•             Reduce steady-state errors

•             Diminish loading parameters sensitivity

•             Decrease voltage fluctuations.

•             True asset utilization

•             Lower total production costs

The most commonly referred role of the servo drive is that of the mediator. The control system sends specific signals to the drive which they amplify from their end. Then they transmit the current to the motor to create and incite a motion and torque that is in sync with the original signal, thereby brining in a balance of power and output in the device. This improves performance by adjusting and anticipating change. 

The key functions of the servo motion controller include command tracking and addressing all disturbance rejection traits that lie in the system. Together they track, mange and streamline processes. It includes the drive or the amplifier, motion controller, sensors for tracking feedback along with a hydraulic pump or air cylinder acting as a linear actuator.