Linkages are mechanical components that connect two or more rigid bodies and allow relative motion between them. They are essential for creating complex and diverse movements in robotics, such as gripping, walking, or articulating. In this article, you will learn about the most common types of linkages used in robotics and how they work.
A four-bar linkage is a simple and versatile linkage that consists of four rigid bars connected by four joints, forming a closed loop. The bars can be straight or curved, and the joints can be fixed or movable. By changing the length, shape, and orientation of the bars, you can create different types of motions, such as linear, rotary, oscillating, or coupler. A four-bar linkage can also be used to transmit force or torque from one point to another. Some examples of four-bar linkages in robotics are grippers, scissors lifts, and crank-rocker mechanisms.
This is one of the fundamental types of linkages in robotics, consisting of four bars connected to form a loop. It's versatile and used in various robotic mechanisms such as grippers, walking robots, and articulated arms due to its ability to generate controlled motion.
A four bar linkage is used to make grippers and a crank rocker mechanism. It has four links and the one link would be input. The output will move accordingly.
A slider-crank linkage is a special type of four-bar linkage that converts rotary motion into linear motion or vice versa. It consists of a crank, a connecting rod, and a slider. The crank is a bar that rotates around a fixed point, the connecting rod is a bar that connects the crank to the slider, and the slider is a bar that slides along a straight path. The slider-crank linkage can be used to create reciprocating or intermittent motions, such as pumping, cutting, or stamping. Some examples of slider-crank linkages in robotics are piston engines, robotic arms, and geneva drives.
It is commonly found in robotic systems, particularly in mechanisms that convert rotary motion into linear motion or vice versa. It consists of a slider moving along a guided path due to the rotational motion of a crank.
It is commonly used in robotic arms. It will make the robot move up and down for rotation of the crank. This will help in making a robot arm to have human-like interaction.
A parallel linkage is a linkage that consists of two or more bars that are parallel to each other and connected by joints at both ends. The bars can move together or apart, but they always maintain the same orientation and distance. A parallel linkage can be used to create stable and precise motions, such as lifting, tilting, or aligning. Some examples of parallel linkages in robotics are forklifts, elevators, and delta robots.
This linkage involves multiple links connected in parallel. It's utilized in parallel manipulators, where multiple arms work together to control the end effector. Parallel linkages often provide increased stability, precision, and load-bearing capacity.
A spherical linkage is a linkage that consists of three or more bars that are connected by spherical joints, forming a spherical polygon. A spherical joint is a joint that allows three degrees of freedom of rotation around any axis. A spherical linkage can be used to create complex and flexible motions, such as twisting, bending, or rolling. Some examples of spherical linkages in robotics are ball-and-socket joints, universal joints, and Stewart platforms.
This type of linkage enables multi-axis movement, allowing for rotations around different axes. It's employed in robotic joints that require a wide range of motion, such as robotic arms used in complex assembly tasks or humanoid robots.
It is normally used to be constrained in a ball joint. It helps in different motions where the common point would be kept at a stationary and only rotation is allowed.
A planar linkage is a linkage that consists of two or more bars that are connected by planar joints, forming a planar polygon. A planar joint is a joint that allows two degrees of freedom of rotation around a fixed axis. A planar linkage can be used to create simple and constrained motions, such as swinging, rotating, or folding. Some examples of planar linkages in robotics are hinges, latches, and pantographs.
These linkages operate within a single plane and are commonly used in robotic mechanisms that require motion in a two-dimensional space. They are often employed in applications like robotic limbs and mechanisms in assembly lines.
The appropriate linkage for a robotic application depends on factors like desired motion, workspace, payload, accuracy requirements, and environmental constraints. Engineers analyze these factors to design and implement linkages that optimize the robot's performance in various tasks.