What Is a Robot Manipulator? How Robotic Arms Move and Handle Objects.

What Is a Robot Manipulator?

A robot manipulator is a mechanical system designed to position, orient, or move a tool or object within a workspace.

Most industrial robotic arms are manipulators.

They use connected links and joints to move an end effector, such as a gripper, welding torch, or inspection tool.

For example, a six-axis industrial robot may use its manipulator to move a component from a conveyor into an assembly fixture.

Key Takeaways

• Robot manipulators position and move tools or objects through coordinated mechanical movements.
• They commonly consist of links, joints, actuators, sensors, and an end effector.
• Their capabilities depend on reach, payload, degrees of freedom, accuracy, and mechanical design.

How Does a Robot Manipulator Work?

Imagine an industrial robotic arm mounted beside an assembly line.

Its base supports a series of mechanical links connected by joints.

Electric motors and transmissions move those joints.

Encoders measure their positions.

The robot's controller coordinates the joint movements to position the tool.

For example, a gripper may need to approach a component, close around it, and transport it to another location.

Kinematic calculations help determine which joint positions correspond to the desired tool pose.

Control algorithms then regulate movement.

What Are the Main Types of Manipulators?

Articulated manipulators: Use rotating joints, often arranged similarly to a shoulder, elbow, and wrist.

Cartesian manipulators: Use linear axes to move tools along defined directions.

SCARA manipulators: Use a mechanical arrangement well suited to many horizontal assembly and handling tasks.

Parallel manipulators: Use multiple mechanical chains connected to a moving platform, as seen in delta robots.

Each architecture has different strengths involving workspace, speed, payload, and movement flexibility.

Manipulator vs. End Effector

The manipulator is the mechanism that positions the working tool.

The end effector is the tool attached to the manipulator.

For example, a robotic arm may be capable of moving to hundreds of positions.

However, whether it can grasp a component depends on the gripper attached to it.

The arm and end effector must therefore be selected together.

What Is a Mobile Manipulator?

A mobile manipulator combines a robotic arm with a moving base.

For example, a robot may travel between workstations and use its arm to inspect or handle components at each location.

This combines manipulation with mobility, but also introduces challenges involving navigation, positioning, stability, and coordination.

Frequently Asked Questions

Is every robot manipulator a six-axis arm?

No. Manipulators can use different numbers of joints and several mechanical architectures.

Can manipulators operate without AI?

Yes. Many industrial manipulators use conventional programming and motion control.

The Bottom Line

Robot manipulators provide the physical movement needed to position tools and handle objects. Their mechanical design determines which tasks they can perform effectively.