Page 66 - Toucpad robotics C11

Description:
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It has a base and two links. The first link has a fixed length L and rotates at an angle (the revolute joint).
l
1 1
The second link is a prismatic joint, which slides in and out along the line defined by the first link. The joint variable
l
here is the displacement, or length, d .
2
The goal is to find the (x,y) coordinates of the end-effector.
l
Mathematical Model:
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The end of the first link is at a distance L from the base.
l
1
The second link extends an additional distance d along the same direction.
2
l
The total distance from the base to the end-effector is (L +d ).
l
1 2
Using the angle , the coordinates of the end-effector are: x=(L +d )cos( ) y=(L +d )sin( )
l
1 1 2 1 1 2 1
Example:
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Consider an RP manipulator with link length L =12 cm.
l
1
If the joint angle is =45° and the prismatic displacement is d2 =8 cm.
l
1
We can calculate the end-effector’s position:
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x=(12+8)cos(45°)=20(0.707)=14.14 cm y=(12+8)sin(45°)=20(0.707)=14.14 cm
The end-effector’s position is (14.14,14.14) cm.
l
Forward kinematics is essential for robot control. It allows the robot’s controller to know exactly where its tools are
in space at any moment, which is a foundational requirement for tasks like picking and placing objects, welding, or
assembly.
Space Robots are Humanity's Eyes and Hands in the Universe
Robots are key explorers of space. Mars rovers like Curiosity and Perseverance are robots
equipped with cameras, drills, and AI to navigate alien terrain. They send back priceless data
BRAINY
FACT about other planets, searching for signs of water or life. Even the International Space Station has
a robotic assistant called Robonaut, designed to help astronauts with tasks in space. Without
robots, exploring distant planets would be nearly impossible because of extreme conditions,
delays in communication, and human survival challenges.

Different Components of a Robot: Frames, Materials, and Wheel Types

We’ve talked about motors, sensors, and microcontrollers as the ‘muscles,’ ‘senses,’ and ‘brain,’ respectively. Now, we’ll
examine the ‘skeleton’ and ‘skin’ of a robot—its frames and materials—as well as its ‘feet’—the various types of wheels it
can use.
A robot is a highly integrated system where the choice of every component, from the main structural frame to the type of
wheels it uses, is a critical design decision. These choices directly impact the robot’s functionality, strength, weight, and
overall performance.

Frames: The Robot’s Skeleton
The Frame is the main structural component of a robot. It acts as the skeleton, providing the physical support for all the
other components, including motors, sensors, batteries, and microcontrollers. The design of the frame determines the
robot’s shape, size, and weight, as well as its ability to withstand forces and impacts.
Fixed Frames: As we discussed, a fixed frame provides a stable reference point. In the context of the robot itself, the
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robot’s main chassis is its fixed frame, even if the robot is mobile. This frame provides a rigid reference for the robot’s
own movements.
Moving Frames: Within the robot, moving frames are attached to components like robotic arms or grippers. The
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pose of these frames changes relative to the robot’s main chassis.

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Touchpad Robotics - XI