System for the stabilization of an object mounted on a moving platform

• US 20020105298A1
• Filed: 02/06/2002
• Published: 08/08/2002
• Est. Priority Date: 07/16/1997
• Status: Active Grant

• Current Assignee: Clipper Windpower Technology, Inc.
• Original Assignee: Antonius C.J. Stavenuiter, Wilhelmus Marie Hermanus Vaassen
• Inventors: Stavenuiter, Antonius C.J., Vaassen, Wilhelmus Marie Hermanus
• Granted Patent: US 6,621,245 B2
• Time in Patent Office: Days
• US Class Current: 318/648
• CPC Class Codes: G01C 21/18 Stabilised platforms, e.g. by gyroscope
• CPC Class Codes: H01Q 1/18 Means for stabilising antennas on an unstable platform
• CPC Class Codes: Y10T 74/1225 with rotor drives
• CPC Class Codes: Y10T 74/1282 with rotor drive

Abstract

The invention concerns an enhanced system for the stabilization of an object with reference to a moving platform. The invention is in particular suitable for the stabilization of a shipborne optical search sensor. The system comprises a stabilization platform and a regulator According to the invention, the regulator calculates control signals for the stabilization platform on the basis of a combination of absolute ship'"'"'s angular position signals and signals produced by rate gyro systems mounted on the stabilization platform. Thus, disturbances caused by flexure of the ship'"'"'s structure and the stabilization platform are effectively compensated for. Said signals are preferably combined by frequency-dependent weighting.

Claims

1. System for stabilizing an object with reference to a moving platform, comprising:

a stabilization device provided with servo motors and a servo control unit;

a stabilization platform connected to a side of the stabilization device to be stabilized;

characterized in that;

the system further comprises an angular velocity measuring device for measuring angular velocities with reference to an inertial coordinate system, which device is connected to the stabilization platform;

the servo control unit is provided with means to connect the servo control unit to an external angular position measuring unit for measuring angular positions of the moving platform;

the servo control unit is designed to control the servo motors on the basis of angular position signals from the angular position measuring unit and angular velocity signals from the angular velocity measuring device.

2. System as claimed in claim 1, characterized in that the servo control unit is provided with calculation means to combine the angular velocity signals and the angular position signals into additional control signals for the stabilization device.

3. System as claimed in claim 2, characterized in that the calculation means, used for calculating the additional control signals, are designed to perform a frequency-dependent weighting of the angular velocity signals and the angular position signals.

4. System as claimed in claim 3, characterized in that the calculation means are designed to perform the frequency-dependent weighting such that the control signals for frequencies below a certain frequency Ω

_o are substantially determined by the angular position signals and the control signals for higher frequencies are substantially determined by the angular velocity signals.

5. System as claimed in claim 4, characterized in that the calculation means comprise two complementary filters, connected to the angular position signals and to the angular velocity signals and summation means to obtain the control signals at least in operational condition.

6. System as claimed in claim 4, characterized in that the calculation means include a Kalman filter, the output of which at least in operational condition, produces the control signals.