A mechanical arm is a robotic, usually programmable, with similar functions to a human arm

Arm

In human anatomy, the arm is the part of the upper limb between the shoulder and the elbow joints. In other animals, the term arm can also be used for analogous structures, such as one of the paired forelimbs of a four-legged animal or the arms of cephalopods...

. The links of such a manipulator are connected by joints allowing either rotational motion (such as in an articulated robot

Articulated robot

An articulated robot is a robot with rotary joints . Articulated robots can range from simple two-jointed structures to systems with 10 or more interacting joints....

) or translational (linear) displacement. The links of the manipulator can be considered to form a kinematic chain

Kinematic chain

A kinematic chain is the assembly of several kinematic pairs connecting rigid body segments. The complexity of the chain is determined by the following factors:...

. The business end of the kinematic chain of the manipulator is called the end effector and it is analogous to the human hand

Hand

A hand is a prehensile, multi-fingered extremity located at the end of an arm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs...

. The end effector can be designed to perform any desired task such as welding, gripping, spinning etc., depending on the application. For example robot arms in automotive assembly line

Assembly line

An assembly line is a manufacturing process in which parts are added to a product in a sequential manner using optimally planned logistics to create a finished product much faster than with handcrafting-type methods...

s perform a variety of tasks such as welding

Welding

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...

 and parts rotation and placement during assembly.

In space

Outer space

Outer space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....

 the Space Shuttle

Space Shuttle

The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

 Remote Manipulator System also known as Canadarm or SSRMS and its successor Canadarm2 are examples of multi degree of freedom

Degrees of freedom (engineering)

In mechanics, degrees of freedom are the set of independent displacements and/or rotations that specify completely the displaced or deformed position and orientation of the body or system...

 robotic arms that have been used to perform a variety of tasks such as inspections of the Space Shuttle using a specially deployed boom with cameras and sensor

Sensor

A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...

s attached at the end effector and satellite

Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

 deployment and retrieval manoeuvres from the cargo bay of the Space Shuttle.

The robot arms can be autonomous

Autonomous robot

Autonomous robots are robots that can perform desired tasks in unstructured environments without continuous human guidance. Many kinds of robots have some degree of autonomy. Different robots can be autonomous in different ways...

 or controlled manually and can be used to perform a variety of tasks with great accuracy.

The robotic arm can be fixed or mobile (i.e. wheeled) and can be designed for industrial or home applications.

Types

• Cartesian robot / Gantry robot:Used for pick and place work, application of sealant, assembly operations, handling machine tools and arc welding. It's a robot whose arm has three prismatic joints, whose axes are coincident with a Cartesian coordinator.
• Cylindrical robot:Used for assembly operations, handling at machine tools, spot welding, and handling at diecasting machines. It's a robot whose axes form a cylindrical coordinate system.
• Spherical robot
  Spherical robot
  A spherical robot is a robot with two rotary joints and one prismatic joint;in other words, two rotary axes and one linear axis.Spherical robots have an arm which forms a spherical coordinate system....
  
   / Polar robot (such as the Unimate
  Unimate
  Unimate was the first industrial robot,which worked on a General Motors assembly line at the Inland Fisher Guide Plant in Ewing Township, New Jersey, in 1961.It was created by George Devol in the 1950s using his original patents...
  
  ):Used for handling at machine tools, spot welding, diecasting, fettling machines, gas welding and arc welding. It's a robot whose axes form a polar coordinate system.
• SCARA robot:Used for pick and place work, application of sealant, assembly operations and handling machine tools. It's a robot which has two parallel rotary joints to provide compliance in a plane.
• Articulated robot
  Articulated robot
  An articulated robot is a robot with rotary joints . Articulated robots can range from simple two-jointed structures to systems with 10 or more interacting joints....
  
  :Used for assembly operations, diecasting, fettling machines, gas welding, arc welding and spray painting. It's a robot whose arm has at least three rotary joints.
• Parallel robot:One use is a mobile platform handling cockpit flight simulators. It's a robot whose arms have concurrent prismatic or rotary joints.
• Anthropomorphic robot: Shaped in a way that resembles a human hand, i.e with independent fingers and thumbs.

See also

• Clamp
  Clamp (tool)
  A clamp is a fastening device to hold or secure objects tightly together to prevent movement or separation through the application of inward pressure...
  
  
• Electric motor
  Electric motor
  An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
  
  
• European Robotic Arm
  European Robotic Arm
  The European Robotic Arm is a robotic arm to be attached to the Russian Segment of the International Space Station. It will be the first robot arm able to work on the Russian space station segments, and will supplement the two Russian Strela cargo cranes that are already installed on the Pirs...
  
  
• Robotics suite
  Robotics suite
  A robotics suite is a visual environment for robot control and simulation. They are typically an end-to-end platform for robotics development and include tools for visual programming and creating and debugging robot applications...
  
  
• Tongs
  Tongs
  Tongs are used for gripping and lifting tools, of which there are many forms adapted to their specific use. Some are merely large pincers or nippers, but the greatest number fall into three classes:...
  
  
• Working envelope