@conference {12201, title = {Control and design of the spherical pointing motor}, booktitle = {, 1993 IEEE International Conference on Robotics and Automation, 1993. Proceedings}, year = {1993}, month = {1993/05/02/6}, pages = {630-636 vol.2 - 630-636 vol.2}, publisher = {IEEE}, organization = {IEEE}, abstract = {A miniature pan-tilt actuator, the spherical pointing motor (SPM) has been built. The SPM is an absolute positioning device, designed to orient a small camera sensor in two degrees-of-rotational-freedom. It is 4 cm{\texttimes}5 cm{\texttimes}6 cm and weighs 160 g. The operating principle of the SPM is to orient a permanent magnet to the magnetic field induced by three orthogonal coils by applying the appropriate ratio of currents to the coils. The open-loop control and design of the SPM are described. Physical characteristics and velocity measurements of the prototype are reported. The SPM is modeled with a simple second order system. Without control, it oscillates substantially when a single impulse is applied. By applying a second impulse without feedback, the oscillation can be reduced by as much as a factor of ten}, keywords = {absolute positioning device, Actuators, camera sensor, CAMERAS, Coils, electric actuators, electric motors, Magnetic field measurement, Magnetic sensors, Open loop systems, open-loop control, orthogonal coils, pan-tilt actuator, permanent magnet, Permanent magnet motors, Permanent magnets, position control, Scanning probe microscopy, second order system, spherical pointing motor, velocity control, Velocity measurement, velocity measurements}, isbn = {0-8186-3450-2}, doi = {10.1109/ROBOT.1993.291888}, author = {Bederson, Benjamin B. and Wallace,R.S. and Schwartz,E.L.} }