Experts Outreach for Motors Used in Industrial Robotics | Expert Out reach

In this era of industrial automation,robots are used for handling various processes for precise and better quality of production. Choosing ideal motor for perfect robot is always a tough task while designing the robot especially for industries. Proper selection of electrical motors in industrial robots requires several parameters to take account for arm control, position, angular and linear movements.

Motor selection is the least understood concept for robotics hobbyists which require strategizing and serious analysis.It involves in determining robot speed, acceleration, torque requirements based on robot weight, wheel size and application where it is to be implemented.There are many types of motors are available in today’s market, but mostly Tiny pager motors, servo motors, linear motors, stepper motors and DC geared motors are used in industrial robots according to their application area.

Improper selection of motor end up with a handicapped robot so what type of motor is best and suited to make industrial robots real, accurate and sufficient to meet all industrial process needs while keeping all realistic specifications in mind?

Here we gathered some insights of these motor from industrial professionals for choosing corresponding motor to be selected for industrial applications.

We encourage you to follow the opinions of experts which aim to provide best motors for industrial robotics with available DC, stepper, brushless and servo motors for precise, cost effective and reliable movements of robot.

Ch.Sampath Kumar
M.tech in VLSI Design
Technical Content Writer

DC motors are available at wide ranges for continuous operation, but it requires gear reductions to suits for the corresponding application. Stepper motor does not require any gear reduction since its stepped operation provides low speed for specified applications. At last servo motors are used for precise and accurate control which is implemented in closed loop operations. But it requires extra feedback and driving circuitry so it is expensive than DC and stepper motor. So the servo motors make the robot more reliable due to its precise motion.

Viswanath Prathap
M.Tech in Electrical Power Engineering
Technical Content Writer

Pick and place Robots are typically found in industries to pick an object from one position or place and to place it at another position or place. For this purpose, angular movements of joints of the robots are need to be controlled, which can be achieved using servo motors. These servo motors are controlled using PWM data given by the robotic controller for actuating the joints of robots. Servo motors are capable of generating an enough torque to move an object quickly from halt position. Thus, these are used as wheels in military and industrial robotic vehicles. Stepper motors may also be used for controlling position but these will consume power even in the rest period for just locking and holding the commanded position. So, servo motors are typically used in industrial robotics as a high performance substitute to the stepper motors.

S. Naresh Reddy

M.tech in Embedded System

Project guide

The structure of mechanical robot must be controlled to perform task. There are three different phases to control robot such as perception, processing and action. Sensors gives the information about the position of its joints and its end effector to the robot, then this information is processed to the control unit and calculate the appropriate signal to the motor which moves mechanically. The huge majority of robots uses electric motors. Repeatedly brushless and brushed DC motors are used in portable robots and AC motors are used in industrial robots. These motors are  preferred in systems with lighter loads, and where the predominant form of motion is rotational.

Suresh Megaji

M. Tech in Wireless Communication Systems

Technical Content Writer

If you want to be involved in ‘robotics’ and their application to ‘industry’, one should know about ‘Motors’ that used in robotics because robotics are dependent mostly on motors.Basically ‘robotic machines’ are used for different applications in production. Different ‘motors’ like D.C, Pulsed, Stepper, Optical drive, Partial turn, and hall effect motors, etc… are used with some techniques to apply them in the industry and make them friendly, like

• D.C motors are used for battery oriented applications, slower speed, mobility applications.
• Wherever we need a rotation oriented application, we can use Stepper motors like unipolar and bipolar motors.
•  For head and arm movements, we can use partial turn motors.
•  If we want to use magnetic fields, we can use Hall Effect and optical drive motors etc.

By using robotics that use smart motors, we can save money, time, space, hazardous movements etc.

Ajay Sahare

Marketing Executive

Industrial robots are used in an industrial manufacturing environment. These are the arms specifically developed for such applications as welding, material handling, painting and others.

Not every mechatronic device used in industrial environment can be regarded as a robot. As defined by ISO (International Standards Organization) an automatically controlled, reprogrammable, multipurpose manipulator programmable in three or more axes is considered to be industrial robot.

Motors used in Industrial Robotics are

• Alternating Current (AC) Motors
• Direct-Current (DC) Motors
• Servo Motors
• Stepper Motors.

1. AC motors can be further subdivided into asynchronous and synchronous types. For example, an induction AC motor is an asynchronous type unit that is essentially comprised of a wire-wound stator and a rotor. Power is connected to the wire and AC current flowing through it induces an electromagnetic (EM) field in the coiled wire, with a strong-enough field providing the force for rotor motion. Synchronous motors are constant-speed motors that operate in synchronism with AC line frequency and are commonly used where precise constant speed is required.

2. Many industrial applications, including robotics, make use of DC motors oftenly because of the ease of controlling speed and direction. They are capable of an infinite speed range, from full speed to zero, with a wide range of loads.

Because DC motors feature a high ratio of torque to inertia, they can respond quickly to changes in control signals. A DC motor can be smoothly controlled to zero motion and instantly accelerated in the opposite direction without the need for complex power-switching circuitry.  Permanent-magnet brushless DC motors are usually more expensive than brush types, although they can provide advantages in power consumption and reliability.

Without a commutator, brushless motors can operate more efficiently and at higher speeds than conventional DC motors. Most brushless DC motors run on a trapezoidal AC waveform, but some of the motors operate with sine waves. Sine wave-driven brushless motors can achieve smooth operation a lower speeds with low torque ripple, making them ideal for grinding, coating, and other applications such as surface finishing.

In case of Brushed DC motors, if you want your motor to rotate slower without losing power, you can use pulse width modulation (PWM). This basically means to switch the motor on and off very fast. This way, the motor rotates with a lower speed as if lower voltage would be applied without taking care of the power.

Basically, the torque generated by a brushed DC motor is too small and the speed is too great to be useful. So, gear reductions are usually used to reduce speed and increase torque.

3. Servo motors are used in closed-loop systems with a digital controller. The controller sends velocity commands to a driver amplifier, which in turn feeds the servo motor. Some form of feedback device, such as a resolver or encoder, provides information on the servo motor’s position and speed. The resolver or encoder may be integrated with the motor or located remotely. Because of the closed-loop system, a servo motor can operate with a specific motion profile that is programmed into the controller.

4. Stepper motors can operate with or without feedback, with the rotation of the motor broken up into small angular steps. It is controlled by pulsed command signals, and can stop precisely at a commanded point without need for brakes or clutch assemblies. When power is removed, a permanent-magnet stepper motor generally remains in its last position. Multiple stepper motors can be maintained in synchronization by driving them from a common source.

Dev Desai

Marketing Executive 

If you plan to get involved in robotics, you will need to familiarize yourself with the many types of motors available, All robotics movement is motorized in one way or another, so it’s important to know what your option are.

DC Motors

Besides being battery operated, a DC motor’s direction of movement is determined by the polarity of the power input. This is an absolute necessity for robotic functions. Fortunately, this type of motor comes in a wide variety of sizes, voltage requirements, and is available everywhere.

The different types of motors are as below

• Mobility base motor
• High speed hobby motor
• Belt drive motor
• Slot car motor
• Pulse operated
• Arm adapted motor
• Bipolar stepper with pointer

Bio Motor

Bio-metal is an amazing substance that has been around for a few years and it has a number of applications in the field of robotics. We can see in the illustration, that a piece of bio-metal wire will shrink by five percent of its length when just a few volts are applied across it. After years of testing, bio-wire has proven to be strong, reliable, and is becoming more useful as new products emerge. Its somewhat slower response time makes it ideal for robotic arm and hand applications, where jerkiness would be problematic. A long piece of wire can produce a significant movement when stretched the entire length of a robotic arm. There are robotic arm kits currently on the commercial market that use the bio metal.

Relays

The relay, in robotics, is almost always used to isolate the power meant for motors, from the power supply for computer function. Motors, because of their low impedance, make heavy current demands on power supplies and create multiple glitches that computers can not tolerate. It is therefore a good idea to use a separate high current source for just motors.

Solenoids

Solenoids are best used as manipulator control devices or switch operators. Their movement is quick and strong, so a spring is almost always used in graspers to soften the action. As you can see in the illustration, control wires are used to close the grasper. These control wires can also act as return springs. Graspers such as this are found more in production line work where the task is very measured and covers narrow parameters.

Secondary Functions

Most motor functions involve mobility, arm, head, or some other visible external movement, however, some motor movements are not so visible. Large industrial robots use hydraulic systems that use pump motors to produce an operating pressure of a hydraulic fluid. Another important secondary function of the motors is controlled adjustment. To improve accuracy, potentiometers that are interfaced with motors are usually multi-turn devices.

Conclusion

Robots can be very complex devices requiring a wide variety of motor-driven movements. This article is meant to give an overview of the range of devices you may be dealing with as a robot builder. It would be a good idea to start by doing research on robotic equipment suppliers and available supplies. There’s a vast amount of product available now and the Internet makes it easy to find, learn about, and use. Whatever your needs, a little ingenuity and the determination that all robot builders seem to have should serve you well.

Samadan Wandre
Marketing Executive

“Motors used in Robotics”

• Mobility base motor
• High speed hobby motor
• Belt drive motor
• Slot car motor
• Pulse operated
• Arm adapted motor
• Bipolar stepper with pointer

Larger motors are best suited for mobility bases that allow robots to maneuver the terrain. Some of these motors come with gearboxes to produce the slower speed and torque needed for mobility. Lowering the voltage to a motor can also slow it down to a more desirable speed. Only experimentation can determine if your motor will operate with a lower voltage. If it does, you’ve saved yourself a lot of trouble, if not, there are other ways of slowing down motors. Some high-speed motors can be used if worm gears or screw gears are used.

An example of the screw gear can be seen in the robotic arm illustration. When the motor turns clockwise the bolt assembly is pulled to the motor and the arm contracts and when it turns counter clockwise, the arm extends. Although the motor shaft is turning fast, the arm action is considerably slower because of the screw reduction.In this following motor circuit illustration, we see a DC motor controlled by a power transistor. A relay switch (Double Pole Double Throw), determines the direction. Transistor Q1 should be a power transistor to take the heavy load of a motor.

Pulsed Motors

Some motors derive a speed reduction by operating from a pulsed DC signal. This signal is usually about one hundred Hz. The speed of the motor can be altered by changing the pulse width, not by changing the frequency of the pulse. Motors like these can be found in surplus electronics shops and can easily be identified by the pulse generator connected to it. Any DC motor can be driven by a pulse source though, and a schematic of such a circuit is included.

As you can see a 555 timer was chosen as the drive oscillator, which produces a frequency of approximately 100 Hz. Resistor R1, and capacitor C, stabilize and isolate the pulse generator from the spikes produced by the motor. Since this device can draw from a power supply of 6 to 12 volts, you might want to change the value of capacitor C4 and C6 for better results, depending on what voltage you use. The pulse output is taken from pin three of IC1 and fed to pin two of IC2, also a 555 timer.

The second timer varies the width of the pulse by adjusting the voltage that is fed to capacitor C6 through potentiometer R5 and resistor R6. The duration of the pulse is what determines the speed of the motor and the pulse width can be adjusted from 10% to 100%.

Transistor Q1 receives the pulse width modulated signal through resistor R7. Since Q1 is a low current device, it passes the signal to Q2, a power transistor that can handle the current demands of the motor. These transistors are not critical and almost any type of low-current power transistor will work. The relay will determine what direction the motor will take.

Stepper Motors

The most complex of all motors is the stepper motor. Like the name infers, the motor turns in degree increments and is pulse operated. The exact degree of turn per step can vary from one manufacturer or model to another, but 20 degrees is popular and produces 18 steps for one complete turn. There are two basic types of stepper motors, bipolar and unipolar. As you can see in the stepper motor schematic, the bipolar is simply a two coil operated motor.

The unipolar type is two coils with center taps. If the center taps are ignored, the unipolar motor can operate as a bipolar type. The two coils in a stepper motor are fed step pulses alternately in polarity from coil to coil. A map of this process is provided in the working diagram to graphically represent the motor action. Unlike conventional DC motors, torque decreases with speed. A special type of drive unit is also required to advance the stepper motor and should be supplied with the motor. It is not recommended that you build a control unit unless the motor is supplied with a good spec sheet that has component recommendations and full schematic.

The motor may require buffers to isolate it from the drive system, or it may require a separate power supply. Whatever the needs, they may vary considerably from one motor to another. Hobby shops are the most reliable suppliers of stepper motors, and although surplus electronic stores may occasionally have them, they may not include the necessary spec information

Partial Turn Motors

Some robotic functions require only a partial turn, such as head or arm movements. The easiest way to achieve these is with position stops and slip gears. An illustration of the mechanical details of this type of motor is provided above. Micro-switches can be used as stop sensors to turn the power off and reset the direction for the next action.

The bottom wheel is connected to the motor while the top wheel is separated from the bottom wheel by a circular piece of felt. When the bottom wheel turns the top wheel turns with it until the stop pin comes in contact with the micro-switch. Some designs do not make provisions for stopping the motor, so simple screws with spacers will function as motor stops.

Bio-Motor

Bio-metal is an amazing substance that has been around for a few years and it has a number of applications in the field of robotics. We can see in the illustration, that a piece of bio-metal wire will shrink by five percent of its length when just a few volts are applied across it. After years of testing, bio-wire has proven to be strong, reliable, and is becoming more useful as new products emerge. Its somewhat slower response time makes it ideal for robotic arm and hand applications, where jerkiness would be problematic. A long piece of wire can produce a significant movement when stretched the entire length of a robotic arm. There are robotic arm kits currently on the commercial market that use the bio metal.

Bhaskar Singh

Marketing Executive

Industrial robots are devices which to a certain extent duplicates human motion along with danger reduction, providing more strength, accuracy and continuity. They need a wide range of motor driven movements depending upon their operational modes, controlling, tools used and work to be performed. An industrial robotic motor should have the potential to handle a wide range of duties than the normal motors in order to specialize on a particular task.

Electric motors are most commonly used in industrial robotics due to highly efficient power sourcing and relatively simple designing which makes them more popular option in terms cost-to-performance rating in all aspects – installing, maintenance and servicing.

Depending upon the work needed, different motors are used for different purposes. For example DC motors are used for movements in clockwise and anticlockwise directions, examples are in cranes and hoists, pulsed motors are used to provide pulsed movements using DC pulse width, partial turn motors are used to provide head and arm like movements and most complex one – stepper motors are used to provide stepped turns in degree increments.

Moreover, depending upon the type of work, motors with different ratings and sizes are used for different purposes.There are several types of motors each having different applications at different places depending on work and robot design.

Mohan Krishna. L

Sales and Support Executive

Robots are used to do the job that could be done by humans and there are many reasons why Robots are better than Humans.

There are two main types of Robot they are:-

Mobile Robot: That move on legs or tracks.

Stationary Robot: That has a fixed base.

Stationary robots usually Robot Arms can be used for picking up objects or doing some other job which involves reaching over to an object.

A Robot Arm has three basic parts:-

• Shoulder joint
• Wrist joint
• Fixed base

Need a robot for the

• Ability to work fast and Hazardous environment.
• Ability to repeat tasks again and again.
• Ability to work accurately.
• Ability to do different tasks.
• Efficiency.

Motor is a device which converts electrical energy to mechanical energy, i.e.,electro-mechanical device.There are two types of motors such as AC Motor and DC Motor

The Motor used in industrial Robotics is Servo Motor. Servo motor  is a simple electrical motor controlled with the help of servo mechanism.If the controlled motor is operated by AC, it is called AC Servo motor otherwise DC  Servo motor.Most servo motors can rotate about 90 to 180 degrees.Even some rotate through a full 360 degrees or more.Some of the Applications of servo motor in Robotics is

• Servo motor application in robotic i.e., A simple pick and place robot, it is used to pick an object from one position and place the object at different position.
• Servo motor in Conveyors are used
• in industrial Manufacturing and assembling units to pass an object from one assembly station to another. For Ex:- A Bottle Filling process.
• Servo motor in Robotic vehicle  here the Servo motor used in the Wheels. Since the continuous rotation servo motor is used.

Dinesh.P
Marketing Executive

Robots be introduced to reduce the human hard works and help to create good fortune to humans for future developments. The term robots mean the machine which mimicking of the various human characteristics. Robotics  includes the knowledge of mechanical,electronics,electrical & Computer science engineering. Motors used in Robots are DC Motors, Stepper Motors and Servo Motors

Where,

• DC Motors are used for continuous Rotation
• Stepper Motors are used for  rotation at few degrees
• Servo Motors are used for positioning ,it can used in cars and planes

Ganesh .J

Marketing Executive

Robots are used to do the job that could be done by humans and also reduces the human effort and time and improve the quality.Motors used in industrial robotics are

• Alternating Current (AC) Motors
• Direct-Current (DC) Motors
• Servo Motors
• Stepper Motors.