Missile Laser Guidance Field for Roll Angle and Axis Offset Detection
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Solution Overview
Problem
Existing methods for determining the roll angle and position of a missile are costly, require complex setups, and are sensitive to angular tilts, making them inefficient for long-range guidance and correction.
Innovation Solution
A method using a laser guidance field with a rotating, intensity-modulated pattern to determine the roll angle and position of a missile by measuring intensity differences at multiple points on the missile, allowing for accurate and cost-effective trajectory correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser guidance field with a moving beam pattern is used to determine roll angle, then measurement precision is improved, but device complexity increases due to the need for pattern generation and Doppler effect utilization
Solution Approach 1:
The patent replaces complex mechanical roll angle sensors with an optical measurement system using laser guidance field and Doppler effect. The roll angle is determined optically by measuring frequency shifts of laser light reflected from the missile surface, eliminating the need for mechanical gyroscopes or accelerometers while achieving high measurement precision.
Solution Approach 2:
The patent utilizes the Doppler effect to convert the missile's roll motion into measurable frequency shifts of the laser light. By changing the parameter being measured from direct mechanical angle to optical frequency, the system achieves high precision roll angle determination through frequency modulation and detection of the laser guidance field.
2Measurement precision
If detection points are positioned laterally to the missile axis, then measurement precision is improved, but ease of operation deteriorates due to alignment requirements
Solution Approach 1:
The patent makes the detection system universal by using the missile's own body as the reflection surface for the laser guidance field. The laterally positioned detection points utilize the missile's cylindrical geometry to reflect laser light back to sensors, allowing the same system to function for both guidance and roll angle measurement without requiring separate alignment mechanisms.
Solution Approach 2:
The missile's body structure serves dual purposes: it is both the object being guided and the reflection surface for the laser guidance field. The cylindrical shape automatically provides the necessary geometric relationship between the laser source, detection points, and sensors, eliminating the need for external alignment equipment or complex positioning mechanisms.
3Reliability
If the method is made insensitive to angular tilting, then reliability is improved, but measurement precision may deteriorate due to reduced signal variation
Solution Approach 1:
The patent measures roll angle in the circumferential dimension around the missile's longitudinal axis rather than in the longitudinal dimension affected by angular tilting. By using laterally positioned detection points that measure frequency shifts caused by circumferential motion, the system isolates the roll measurement from the effects of pitch and yaw tilting, achieving both reliability and precision.
Solution Approach 2:
The patent separates the measurement functions by using multiple laterally positioned detection points, each independently measuring the Doppler frequency shift. This segmentation allows the system to determine roll angle from the differential measurements while being insensitive to common-mode angular tilting, as the tilting affects all detection points equally and can be differentiated from the roll-induced differential signals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables simultaneous determination of the roll angle and position with high accuracy and minimal effort, independent of the missile's roll rate and angular tilts, suitable for guided ammunition.
Implementation Method 1
a laser source (40) which emits laser light (44)
Implementation Method 2
a pattern disk (42) which is rotatable around the target axis (18) and has a fixed pattern (30) that is imprinted on it; the pattern (30) is imprinted in an invariant manner on the laser beam pattern
Implementation Method 3
determination of the instantaneous roll angle position based on Doppler effect-induced frequency shifts at the detection point
Data Source
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AI summary
To determine the relative position (RL) of a missile (4) with respect to a target axis (18), a transmitter (24) emits a laser guidance field (26) with a pattern (30) varying and rotating around the target axis (18) along the target axis (18). The current intensity (IA1-3) of the laser guidance field (26) is recorded at three different measurement points (MP1-3) at known measurement positions (ML1-3) on the missile (4). From this, a difference (DPA,B) of polar angles (PW) between the two measurement points (MP1-3) of each pair (PA,B) with respect to the target axis (18) is determined for at least two different pairs (PA,B) of the three measurement points (MP1-3). The relative position (RL) is then determined as the offset (AL) of the roll axis (28) from the target axis (18) and the rotation angle (DW) of the missile (4) about the roll axis. (28) determined with respect to a zero angle (NW).To guide a guided missile (4), the above procedure is carried out for the guided missile as missile (4) and the guidance device (16) is controlled towards the target axis (18) depending on the relative position (RL). A missile assembly (22) includes the aforementioned transmitter unit (24), which emits the laser guidance field (26), and the missile (4), which determines the relative position (RL).