Cylindrical Robot : Diagram , Construction , Applications

Cylindrical Coordinate Robots are robots whose axes form a cylindrical coordinate system. Used for

-assembly operations,
-handling at machine tools,
-spot welding, and
-handling at die casting machines.

The motion of the main arm is up and down. The robot can perform this motion by extending a cylinder that’s built into the arm. In most cylindrical robots, the up-and-down motion is provided by a pneumatic cylinder, and the rotation is generally provided by a motor and gears.

Construction Of Cylindrical Robot:

consists of two orthogonal slides, placed at 90° angle, mounted on a rotary axis
• Reach is accomplished as the arm of the robot moves in and out.
• For vertical movement, the carriage moves up and down on a stationary post, or the post can move up and down in the base of the robot.
• Movement along the three axes traces points on a cylinder
• A cylindrical configuration generally results in a larger work envelope than a Cartesian configuration.

Cylindrical Coordinate System

A cylindrical coordinate system is a three-dimensional coordinate system that specifies point positions by the distance from a chosen reference axis, the direction from the axis relative to a chosen reference direction, and the distance from a chosen reference plane perpendicular to the axis. The latter distance is given as a positive or negative number depending on which side of the reference plane faces the point.

The origin of the system is the point where all three coordinates can be given as zero. This is the intersection between the reference plane and the axis.

The axis is variously called the cylindrical or longitudinal axis, to differentiate it from the polar axis, which is the ray that lies in the reference plane, starting at the origin and pointing in the reference direction.

The distance from the axis may be called the radial distance or radius, while the angular coordinate is sometimes referred to as the angular position or as the azimuth. The radius and the azimuth are together called the polar coordinates, as they correspond to a two-dimensional polar coordinate system in the plane through the point, parallel to the reference plane. The third coordinate may be called the height or altitude (if the reference plane is considered horizontal), longitudinal position,or axial position.

However, cylindrical configurations have some disadvantages.
– Their overall mechanical rigidity is reduced because robots with a rotary axis must overcome the inertia of the object when rotating.
– Their repeatability and accuracy is also reduced in the direction of rotary movement.
– The cylindrical configuration requires a more sophisticated control system than the Cartesian configuration.

Application Of Cylindrical Configurations
Typical Applications for Cylindrical Configurations Include The Following:
• Machine loading and unloading
• Investment casting
• Conveyor pallet transfers
• Foundry and forging applications
• General material handling and special payload handling and manipulation
• Meat packing
• Coating applications
• Assembly
• Injection molding
• Die casting