74 lines
2 KiB
Markdown
74 lines
2 KiB
Markdown
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# Robot Kinematics Library
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This library calculates the forward and inverse kinematics for an arbitrary
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robot arm in an arbitrary number of dimensions.
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## Install
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This library depends on [NumIdr](https://github.com/kiana-S/numidr), which
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must be installed first.
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To install:
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``` shell
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git clone https://github.com/kiana-S/idris2-robotlib
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cd idris2-robotlib
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idris2 --install robotlib.ipkg
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```
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## Tutorial
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``` idris
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import Kinematics.Forward
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import Kinematics.Inverse
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```
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<!-- idris
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import Data.Vect
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import Data.Fuel
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-->
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A robot arm is a value of type `ArmElement n`, where *n* is the number of
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dimensions the robot operates in. An arm is constructed by chaining together
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arm elements left-to-right using the `<+>` operator. Some examples of arm elements are:
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- `link`, a link in a direction given by a vector
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- `linkX`, a link in the +X direction given its length
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- `revolute2D`, a 2D revolute joint
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- `revoluteX, revoluteY, revoluteZ`, 3D revolute joints along the corresponding axis
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For example, here is a simple SCARA robot arm in 2D space:
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``` idris
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scara : ArmElement 2
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scara = revolute2D (-pi/2) (pi/2) <+> linkX 5
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<+> revolute2D (-pi/2) (pi/2) <+> linkX 7
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```
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The joint constructors take as arguments their limit angles. All angles are
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given in radians.
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To calculate the forward kinematics of a robot arm, use the function `forward`,
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which takes in an arm and a vector of joint values. For example:
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``` idris
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endPos : Maybe (Point 2 Double)
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endPos = forward scara (vector [2.1, 1.6])
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```
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If any of the joint values are outside of the respective joint's limits, the
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function will return `Nothing`.
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To numerically calculate the inverse kinematics of a robot arm, use the
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function `inverse`. It takes in the robot arm and an endpoint, along with a
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"fuel" value that limits how many iterations the algorithm performs, one of
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`forever` or `(limit n)`.
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``` idris
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calcInverse : Maybe (Vector 2 Double)
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calcInverse = inverse forever scara (point [9, 4])
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```
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If the algorithm cannot find any solutions within the joint limits, it will
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return `Nothing`.
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