Browse Prior Art Database

Pitch and Yaw Rotary Axis Calibration Device

IP.com Disclosure Number: IPCOM000053041D
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Heikkinen, DW: AUTHOR

Abstract

The pitch and yaw axes of the manipulator use potentiometers for feedback of actual position. These potentiometers are non-linear. The software which uses the input from the potentiometers assumes linearity; therefore, with the proposed device the non-linearities can be found, and the error induced by the non-linearities can be reduced.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 88% of the total text.

Page 1 of 2

Pitch and Yaw Rotary Axis Calibration Device

The pitch and yaw axes of the manipulator use potentiometers for feedback of actual position. These potentiometers are non-linear. The software which uses the input from the potentiometers assumes linearity; therefore, with the proposed device the non-linearities can be found, and the error induced by the non-linearities can be reduced.

This pitch and yaw rotary axes calibration device requires that a gripper 10 with a LED (light-emitting diode) 12 be attached to the axis assembly, as shown in Fig. 1. The calibration device makes use of the LED and the pitch axis for pitch calibration and the yaw axis for yaw calibration.

Referring to Fig. 2, there is shown a schematic diagram of the calibration device 13. The device is used by causing the motor 14 to rotate so as to cause the gripper fingers 16 to pass along the entire device. The gripper fingers 16 are slightly open (Fig. 2a), so that each time the LED 12 detects the presence of a calibration hole 18, the feedback from the potentiometer is recorded as well as the known angle it has moved from the horizontal position or 0 degree position.

The rotary axis makes a few passes through the complete range of the calibration device 13, and the readings are averaged.

From the readings, the actual angle is plotted versus the expected angle, and a linear approximation is derived. A sample plot is shown in Fig. 3.

The same procedure can be used to calibrate the yaw axis except t...