Capacitor sensor including two plates having both conductive and non conductive regions
A capacitive sensor for characterizing force or torque includes a first plurality of non-patterned conductive regions and a first plurality of patterned conductive regions, and a second plurality of non-patterned conductive regions and a second plurality of patterned conductive regions. The first and second pluralities of non-patterned conductive regions are facing and the first and second pluralities of patterned conductive regions are facing.
1. A capacitive sensor for characterizing at least one of force or torque, comprising:
a first non-patterned conductive region and a first patterned conductive region coupled to a first plate; and
a second non-patterned conductive region and a second patterned conductive region coupled to a second plate;
wherein the first and second non-patterned conductive regions are facing each other and operable to detect an out-of-plane movement of the first plate relative to the second plate, and the first and second patterned conductive regions are facing each other and operable to detect an in-plane movement of the first plate relative to the second plate.
2. The capacitive sensor of claim 1 , wherein the first non-patterned conductive region is one of a first plurality of non-patterned conductive regions and the first patterned conductive region is one of a first plurality of patterned conductive regions.
3. The capacitive sensor of claim 1 , wherein the second non-patterned conductive region is one of a second plurality of non-patterned conductive regions and the second patterned conductive region is one of a second plurality of patterned conductive regions.
4. The capacitive sensor of claim 1 , wherein the capacitive sensor measures a lateral translation or a rotation of the first plate relative to the second plate based on the detected in-plane movement.
5. The capacitive sensor of claim 1 , wherein the capacitive sensor measures an axial displacement of the first plate relative to the second plate based on the detected out-of-plane movement.
6. The capacitive sensor of claim 1 , wherein the first plate is spaced apart from and generally axially aligned with the second plate.
7. The capacitive sensor of claim 1 , wherein the first patterned conductive region or the second patterned conductive region comprises at least a first group of conductive strips and a second group of conductive strips.
8. The capacitive sensor of claim 1 , wherein the first patterned conductive region or the second patterned conductive region comprises a regularly alternating pattern of conductive strips and non-conductive strips.
9. The capacitive sensor of claim 1 , wherein a size of the first non-patterned conductive region is different than a size of the second non-patterned conductive region.
10. The capacitive sensor of claim 1 , further comprising a reference conductive pad coupled to the first plate or the second plate, the reference conductive pad is configured to provide at least one signal for calibrating the capacitive sensor against environmental factors affective capacitance signals.
11. The capacitive sensor of claim 1 , wherein the second non-patterned conductive region and the second patterned conductive region are conductively coupled as a common ground.
12. The capacitive sensor of claim 1 , wherein the first patterned conductive region is one of a plurality of first patterned conductive regions arranged around a center point.
13. The capacitive sensor of claim 12 , wherein the first plurality of patterned conductive regions are arranged equally distributed from one another around the center point.
14. The capacitive sensor of claim 13 , wherein the first plurality of patterned conductive regions comprise three patterned conductive regions arranged approximately 120 degrees from one another.
15. The capacitive sensor of claim 1 , further comprising a base, wherein the first non-patterned conductive region and the first patterned conductive region are fixed relative to a first base portion of the base, and wherein the second non-patterned conductive region and the second patterned conductive region are fixed relative to a second base portion of the base.
16. The capacitive sensor of claim 15 , wherein at least part of the first base portion and at least part of the second base portion are rotationally displaceable relative to each other.
17. The capacitive sensor of claim 15 , wherein at least part of the first base portion and at least part of the second base portion are laterally displaceable relative to each other.
18. The capacitive sensor of claim 15 , wherein at least part of the first base portion and at least part of the second base portion are axially displaceable relative to each other.
19. The capacitive sensor of claim 15 , further comprising a cover configured to couple to the base such that the cover and the base enclose the first and second surfaces.
20. The capacitive sensor of claim 15 , wherein the first base portion comprises a ring-shaped region and the second base portion comprises a central region that is radially connected to the ring-shaped region by a cross-coupling member that allows the central region to move relative to the ring-shaped region.
21. The capacitive sensor of claim 15 , wherein the first base portion is coupled to a first robotic arm link of a robotic arm and the second base portion is coupled to a second robotic arm link of the robotic arm.
22. The capacitive sensor of claim 21 , wherein the capacitive sensor measures a direction of force or a direction of torque based on a displacement between the first base portion coupled to the first robotic arm link and the second base portion coupled to the second robotic arm link.
23. The capacitive sensor of claim 22 , wherein the capacitive sensor generates a signal based on the measured direction of force or direction of torque for use in one or more control algorithms for the robotic arm.
24. The capacitive sensor of claim 23 , wherein the signal is input into a virtual model of the robotic arm and the response of the virtual model to the input forms a basis of an actuator command for the robotic arm according to the one or more control algorithms.