HYBRID STRAPDOWN GUIDANCE SYSTEM

• US 3,746,281 A
• Filed: 08/04/1971
• Issued: 07/17/1973
• Est. Priority Date: 08/04/1971
• Status: Expired due to Term

• Current Assignee: William W. Stripling
• Original Assignee: William W. Stripling
• Inventors: Stripling, William W.
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Tudor, H. J.
• Application Number:
  US05/168,883
• Time in Patent Office: 713 Days
• Field of Search: 244/3.2
• US Class Current: 244/3.2
• CPC Class Codes: G01C 21/166 Mechanical, construction or arrangement details of inertial navigation systems
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems

Abstract

A guidance system for guiding a missile in its boost phase. The system uses a two-axis spaced-fixed platform with pitch and yaw gimbals controlled by a dual-axis gyro that is mounted on the platform. A single-axis roll gyro is strapped-down to the missile frame for controlling the missile in roll. The platform is controlled in roll by the missile frame. The system has three accelerometers on the platform, two being a part of the dual-axis gyro for sensing acceleration in pitch and yaw, and the third being a range accelerometer for sensing acceleration along the longitudinal axis of the missile. The sensed pitch and yaw acceleration voltages are processed in a guidance computer and are compared therein with programmed flight path voltages. If there is any difference between corresponding voltages in pitch and yaw, corrective guidance command signals are generated. The guidance command signals are fed to a pitch-and-yaw signal processor for processing. This processor provides as outputs command signals to airframe actuators for guiding the missile in pitch and yaw. Output signals from the roll gyro are likewise applied, through a roll control signal processor, to the same airframe actuators for guiding the missile in roll. The pitch and vertical acceleration voltages are so processed in the guidance computer that an engine cut-off signal is generated at the proper time.

Claims

1. A missile with an airframe and a guidance system comprising:

a space-stable platform in said missile;

means mounted on said platform for sensing pitch and yaw acceleration and providing pitch and yaw acceleration signals;

means mounted on said platform for sensing vertical acceleration of said platform and for providing a vertical acceleration signal;

a guidance computer having inputs to which said pitch, yaw, and vertical acceleration signals are applied and having respective outputs for a missile engine cut-off signal, for pitch guidance signals and for yaw guidance signals;

first and second transducers mounted between said stable platform and the airframe of said missile for respectively responding to the angles between said platform and pitch and yaw axes and for providing respective pitch and yaw angle signals;

a signal processor having respective inputs for each of said pitch and yaw guidance signals, and said pitch and yaw angle signals, said processor also having respective outputs for pitch and yaw command signals;

a sensor mounted on said missile airframe for sensing roll of said missile about its longitudinal axis and for providing a signal related to the roll angle;

a plurality of aerodynamic control surfaces on said missile airframe; and

a respective plurality of actuators for said control surfaces, with said pitch and yaw command signals applied to respective inputs of said actuators, and with said roll signal applied to inputs of said actuators.

2. The system of claim 1 wherein said guidance computer includes means to provide a pitch dispacement reference signal and a vertical displacement reference signal;

means for deriving pitch and vertical displacement signals from said pitch and vertical acceleration signals; and

means for comparing said reference signals and the derived signals to provide the engine cut-off and pitch guidance commands; and

further means in said computer for deriving from said yaw acceleration signals yaw displacement signals as yaw guidance command signals.

3. The system of claim 2 wherein said pitch and yaw signal processor includes means for respectively comparing said pitch commands and said pitch angle signals and said yaw guidance commands and said yaw angle signals to provide respectively said pitch and yaw control commands.