Force vector reconstruction method using optical tactile sensor

A force vector reconstruction method that uses an optical tactile sensor, said sensor having a tactile portion comprising a transparent elastic body and a plurality of marker groups provided in said body, each marker group being comprised of a number of colored markers, with markers constituting different marker groups having different colors for each group, said method comprising the steps of:

• obtaining a marker image by taking an image of behavior of colored markers when an object contacts a contact surface of the elastic body;
• obtaining information relating to the marker behavior from the marker image, said information being more than the number of force vectors to be obtained;
• setting a small region of a specified size in the marker image and arranging a plurality of force vector sampling points inside and outside the small region;
• calculating force vectors acting on the sampling points both inside the small region and outside the small region by supplying marker information inside the small region to a transfer function;
• and
• adopting force vectors acting on at least some sampling points of the plurality of sampling points arranged inside the small region and discarding the remaining calculated force vectors acting on the remaining sampling points.

A force vector reconstruction device that uses an optical tactile sensor, said sensor having a tactile portion comprising a transparent elastic body and a plurality of marker groups provided in said body, each marker group being comprised of a number of colored markers, with markers constituting different marker groups having different colors for each group, said device comprising:

• means for obtaining a marker image by taking an image of behavior of colored markers when an object contacts a contact surface of the elastic body;
• means for obtaining information relating to the marker behavior from the marker image, said information being more than the number of force vectors to be obtained;
• means for setting a small region of a specified size in the marker image and arranging a plurality of force vector sampling points inside and outside the small region;
• means for calculating force vectors acting on the sampling points both inside the small region and outside the small region by supplying marker information inside the small region to a transfer function;
• and
• means for adopting force vectors acting on at least some sampling points of the plurality of sampling points arranged inside the small region and discarding the remaining calculated force vectors acting on the remaining sampling points.

In a force vector reconstruction device that uses an optical tactile sensor, said sensor having a tactile portion comprising a transparent elastic body and a plurality of marker groups provided in said body, each marker group being comprised of a number of colored markers, with markers constituting different marker groups having different colors for each group, a program for causing a computer constituting said force vector reconstruction device as:

• means for obtaining a marker image by taking an image of behavior of colored markers when an object contacts a contact surface of the elastic body;
• means for obtaining information relating to the marker behavior from the marker image, said information being more than the number of force vectors to be obtained;
• means for setting a small region of a specified size in the marker image and arranging a plurality of force vector sampling points inside and outside the small region;
• means for calculating force vectors acting on the sampling points both inside the small region and outside the small region by supplying marker information inside the small region to a transfer function;
• and
• means for adopting force vectors acting on at least some sampling points of the plurality of sampling points arranged inside the small region and discarding the remaining calculated force vectors acting on the remaining sampling points.