Feature/elevation correction arm

extend itaEimar.armCorrectionAngle from single value static compensation to two-value offset compensation (measured at 90 deg and 0 deg) that considers the static offset and deflection of the arm from the weight of the attachment.

applications/Hardware/ITAMotorControl/itaEimar.m

@@ -117,6 +117,9 @@ classdef itaEimar < itaMeasurementTasksScan
         failed_command_repititions  =   5;  % How often do we repeat commands until we throw an error?
         doSorting           =     true;     % sort the measurement coordinates for arm due to shorter measurement time 
         armCorrectionAngle  =   0;          % Correct the position of the arm. Check at 90° if horizontal. Value <0 -> higher position
+                                            % for heavy objects use [offset at 90, offset at zero] to compensate sag
+                                            % CAUTION: due to backlash always move to a target position from the same direction
+                                            % i.e. only decrease theta throughout a measurement
     end
     % *********************************************************************
     properties (Access = protected, Hidden = true)
@@ -925,7 +928,18 @@ classdef itaEimar < itaMeasurementTasksScan
                 return;
             end
             
-            angle = angle - 119.01 + this.armCorrectionAngle; % Larger substractive value: Higher position. Checkt at 90�.
+            %apply arm correction 
+            % Larger substractive value: Higher position. Checkt at 90 deg
+            % for static compensation when using lightweight attachment,
+            % e.g. a microphon. When using a loudpeaker use the 2 value
+            % compensation [offset at 90 deg, offset at 0 deg] to
+            % compnesate sag in the arm
+            if numel(this.armCorrectionAngle) < 2
+                corr_angle = ones(2) * this.armCorrectionAngle;
+            else
+                corr_angle = this.armCorrectionAngle;
+            end
+            angle = angle - 119.01 + corr_angle(2) + (corr_angle(1) - corr_angle(2))*sin(angle*pi/180);