Diff: ScaraArms.h

Revision:

0:9a3fc5ff8de3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ScaraArms.h	Fri May 15 08:50:58 2015 +0000
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+// SCARA_Arms library
+// Code to compute the shoulder angles required to move a Dual-Arm SCARA robot to required x,y position
+// More information at http://robdobson.com/scara-arm-calculations
+// Copyright (C) Rob Dobson 2013-2015, MIT License
+
+#ifndef SCARAARMS_H
+#define SCARAARMS_H
+
+// Description of a Dual-Arm SCARA robot
+// The two arms of the robot are akin to two human arms with the hands permanently clasped together
+// The arms are always in the same plane (generally horizontal) and the hands hold a stick (also in the same plane)
+// On the end of the stick is the tool (pen/actuayor/nozzle/laser etc)
+
+class ScaraArms
+{
+public:
+    // Constructor
+    // The measurements required to describe a Dual-Arm SCARA robot of the kind described above are:
+    // 1) Distance between shoulders
+    // 2) Distance from shoulder to elbow
+    // 3) Distance from elbow to hand
+    // 4) Distance from hand to tool (length of stick holding the tool)
+    ScaraArms(double betweenShouldersMM, double shoulderToElbowMM, double elbowToHandMM, double handToToolMM);
+    
+    // Compute the angles at the shoulders given the required XY position of the tool in radians
+    // Note that the way the angles are measured is that theta1 (the left arm angle) is measured counter-clockwise from 3 O'Clock
+    // theta2 (the right arm angle) is measured clockwise from 9 O'Clock
+    // To calculate both clockwise from 9 O'Clock use PI-theta2
+    // To convert the angles to degrees multiply by 180/PI
+    // The XY position has it's origin (0,0) at the left shoulder
+    void ConvertXYtoScara(double x, double y, double &theta1, double &theta2);
+
+    // Compute the XY position of the tool given the angles at the shoulders
+    // See the comments above for the reverse calculation concerning the way the angles are measured and the origin 
+    // of the XY coordinates
+    // These calculations use a different mathematical model as the conversion in this direction is simpler and
+    // it provides a useful cross check
+    void ConvertScaratoXY(double theta1, double theta2, double &x, double &y);
+    
+private:
+    double _betweenShouldersMM;
+    double _shoulderToElbowMM;
+    double _elbowToHandMM;
+    double _handToToolMM;
+};
+
+#endif
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