fixed issues in sigmoid sensor model causing inverted response (annular partitions)

sensorModels/@fixedCardinalSensor/fixedCardinalSensor.m

@@ -0,0 +1,13 @@
+classdef fixedCardinalSensor
+    % Senses in the +/-x, +/- y directions at some specified fixed length
+    properties
+        alphaTilt = NaN;
+        r = 0.1; % fixed sensing length
+    end
+
+    methods (Access = public)
+        [obj] = initialize(obj, r);
+        [neighborValues, neighborPos] = sense(obj, agent, sensingObjective, domain, partitioning);
+        [value] = sensorPerformance(obj, agentPos, agentPan, agentTilt, targetPos);
+    end
+end