Robot joints move because they are pushed or pulled by actuators, which are powered by electricity, air (pneumatics), or liquids (hydraulics). These actuators act as the "muscles" of the robot, enabling its joints to bend, turn, and rotate.
Here's a more detailed breakdown:
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Joints: These are the points where different parts of the robot are connected, allowing for movement. Think of them like human joints (elbows, knees, shoulders).
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Actuators: These are the mechanisms that cause the joints to move. They can be:
- Electric Motors: These are the most common type of actuator. They use electricity to create rotational motion. Different types of electric motors (e.g., DC motors, servo motors, stepper motors) are used depending on the precision and power requirements of the joint.
- Pneumatic Actuators: These use compressed air to generate force and movement. They are often used for tasks requiring fast and powerful movements.
- Hydraulic Actuators: These use pressurized liquids (typically oil) to generate force and movement. They are used for applications requiring very high force and precision.
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Mechanisms: The actuators are connected to the joints through various mechanisms that translate the actuator's motion into the desired joint movement. These mechanisms can include:
- Gears: Gears are used to increase or decrease torque and speed, and to change the direction of rotation.
- Leadscrews: Leadscrews convert rotational motion into linear motion.
- Cables and Pulleys: These are used to transmit force over a distance.
- Linkages: Linkages are systems of rigid bodies connected by joints, used to create complex movements.
In essence, the actuator provides the power, and the mechanisms transmit and modify that power to move the joint in a specific way. The type of actuator and mechanism used depends on the specific requirements of the robot and the task it needs to perform. For example, a small, precise robot arm might use electric motors and gears, while a large, heavy-duty industrial robot might use hydraulic actuators.
