ROBOTIC ARMSROBOTIC ARMS

Gateway Coalition - WSU

Rahul K. Shah

FUNDAMENTALSFUNDAMENTALS

MECHANICAL MANIPULATOR– Can perform a variety of tasks– also called an industrial robot

CONSTRUCTION & PARTS– Non-moving Base/Frame– Links

• position and orientation depends on the co-ordinate system

– Joints• allow motion of neighboring links

• can be rotary, sliding or prismatic

FUNDAMENTALSFUNDAMENTALS

CONSTRUCTION & PARTS (contd.)– End-Effector

• in our case it will be the Gripper

TERMINOLOGY– Workspace

• area within the reach of a manipulator

– Tool Frame• gives the position of the manipulator w.r.t the

Base Frame

FUNDAMENTALSFUNDAMENTALS

TERMINOLOGY (contd.)– Jacobian

• matrix quantity which helps with velocity analysis using Mapping

– Joint Torques• These are to be calculated whenever there is a

contact with another object or the need of applying a static force arises

FUNDAMENTALSFUNDAMENTALS

TYPES OF CONTROLS– Linear position control– Nonlinear position Control– Force Control– All of the above need to be programmed via a

robot programming language.

SPECIFICATIONSSPECIFICATIONS

An example of standard specifications

5 degrees of freedom,vertical articulated robot.

Waist Rotation 300º (max. 120º/sec) J1 axisShoulder Rotation 130º (max 72º/sec) J2 axisElbow Rotation 110º(max. 109º/sec) J3 axisWrist Pitch ± 90º (max. 100º/sec) J4 axisWrist Roll ± 180º (max. 163º/sec) J5 axisUpper Arm 250 mmFore Arm 160 mm

75 mm from the mechanical interface (center of gravity)

1000 mm/sec (wrist tool surface)0.3 mm (roll center of the wrist tool surface)Electrical servo drive using DC servo motorsApprox. 19 kgf

J1 to J3 axes: 30W; J4 J5 axes: 11W

Robot Weight

Motor Capacity

Operation Range

Arm Length

Maximum Path Velocity

Mechanical Structure

Position Reliability

Drive System

Max. 1.2 kgf (including hand wt.)Weight Capacity

5-AXIS ROBOTS5-AXIS ROBOTS

CONCERNSCONCERNS

Typical Weight to Payload ratio :- 12-26– An arm this heavy is going to affect the

performance of the wheelchair.Size of links due to the size of

motors.– Typically around 4 to 5 in.

QUESTIONS AND QUESTIONS AND COMMENTS??COMMENTS??