What do you plan to achieve with a robot? Most (if not all) ways of using a robot require the magical device to move. Movement occurs at the joints of the robot. Consequently, motion is one of the critical factors roboticists consider when designing robots.
What is the logic behind the joint movement? How relevant is this to you, as a consumer of robots? The answer to these questions lies in your understanding of the degrees of freedom. Jump with me into the content.
First, what is a degree of freedom? Mechanics define a degree of freedom as specific modes that enable a system to move. There are two basic dimensions of motion. These are rotation and translation.
Rotation is movement along an angle, not equal to 180 degrees. Rotation subdivides into pitch, yaw, and roll. The translation is displacement along the x-axis or y-axis. It furthers down into forward-backward, up-down, or left-right motions.
Here’s an explanation of the motion breakdowns. Let’s use a human shoulder, elbow, and wrist. The shoulder can move upwards or downwards. This is up-down motion is called pitch.
The shoulder can move the left-right direction as well. This motion is known as yaw. Finally, the shoulder can achieve circular motion. This motion is referred to as roll.
Pitch, yaw, and roll constitute the degrees of freedom.
The shoulder can move in 3 ways, pitch, yaw, and roll. The elbow can achieve pitch only while the wrist can achieve roll and pitch. Mechanically, the shoulder has 3 degrees of freedom, the elbow has 1 whereas the wrist has 2 degrees of freedom.
Whenever a robot moves, start, and stop commands run at the joints. This initiates a motion dependent on the intended action of the robot. The commands depend on the position, distance, acceleration, deceleration, and direction of the joints.
And what determines the efficiency of a joint? The degree of freedom accompanying a joint! To the most extent, this implies that the more degrees of freedom, the better a robot is. Let me explain.
Speed vs Degree of Freedom
In most cases, a robotic arm with a higher degree of freedom moves and accomplishes tasks faster than one with lower degrees of freedom. The robot can easily reach a target task since it has a better adjustment to locomotion.
Acceleration vs Degree of Freedom
Acceleration is speed per unit time (s). Robots with higher degrees of freedom accelerate faster than those with lower degrees of freedom. Although this is not always the case, it happens in most scenarios.
How does acceleration affect the relevance of a robot? You should aim for robots that can easily detect and react to slight changes in the workplace.
Acceleration enables robots to react to various stimuli and avoids danger. Besides, the robot can easily save an industrial task from delays or going bad.
Accuracy vs Degree of Freedom
There is no direct relationship between the degree of freedom and state of a system lacking mistakes. To some extent, however, a robot whose joints achieve several angles of motion encounters fewer errors than one with fewer degrees of freedom.
Repeatability vs Degree of Freedom
Repeatability is the trait of the robot to undertake a task over time, producing the same result. For example, in packaging. There is no direct relationship between accomplishing repetitive tasks and the number of joint movements.
However, the more customized a robot is to act and react to commands, the better suited it is to achieve repetitive tasks.
Final Verdict
Before you spend on a robot, understand how a robot operates. Why do some robots accomplish certain tasks better than others? Many factors contribute to robotic efficiency.
A typical example of the factors is the degree of freedom in a robotic arm. This affects speed, acceleration, accuracy and the action of the robot on repetitive tasks.
