In the engineering field of

robotics Robotics is an interdisciplinary branch of computer science and engineering. Robotics involves design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist humans. Robotics integrat ...

, an arm solution is a set of calculations that allow the real-time computation of the

control Control may refer to: Basic meanings Economics and business * Control (management), an element of management * Control, an element of management accounting * Comptroller (or controller), a senior financial officer in an organization * Controllin ...

commands needed to place the end of a

robotic arm A robotic arm is a type of mechanical arm, usually programmable, with similar functions to a human arm; the arm may be the sum total of the mechanism or may be part of a more complex robot. The links of such a manipulator are connected by joints ...

at a desired position and orientation in space. A typical

industrial robot An industrial robot is a robot system used for manufacturing. Industrial robots are automated, programmable and capable of movement on three or more axes. Typical applications of robots include welding, painting, assembly, disassembly, pick a ...

is built with fixed length segments that are connected either at

joints A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

whose angles can be controlled, or along linear slides whose length can be controlled. If each angle and slide distance is known, the position and orientation of the end of the robot arm relative to its base can be computed efficiently with simple

trigonometry Trigonometry () is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. T ...

. Going the other way — calculating the angles and slides needed to achieve a desired position and orientation — is much harder. The mathematical procedure for doing this is called an arm solution. For some robot designs, such as the

Stanford arm Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is considere ...

, Vicarm

SCARA robot The SCARA is a type of industrial robot. The acronym stands for Selective Compliance Assembly Robot Arm or Selective Compliance Articulated Robot Arm. By virtue of the SCARA's parallel-axis joint layout, the arm is slightly compliant in the X ...

cartesian coordinate robot A Cartesian coordinate robot (also called linear robot) is an industrial robot whose three principal axes of control are linear (i.e. they move in a straight line rather than rotate) and are at right angles to each other. The three sliding joi ...

s, this can be done in closed form. Other robot designs require an

iterative Iteration is the repetition of a process in order to generate a (possibly unbounded) sequence of outcomes. Each repetition of the process is a single iteration, and the outcome of each iteration is then the starting point of the next iteration. ...

solution, which requires more computer resources.

External links

infolab.stanford.edu
- The Stanford Arm (1969), with a configuration such that the mathematical computations (arm solutions) were simplified to speed up computations
D. L. Pieper, The kinematics of manipulators under computer control
PhD thesis, Stanford University, Department of Mechanical Engineering, 1968. Robot kinematics Trigonometry {{Mathapplied-stub

See also

External links