ELECTRO-OPTICAL GUIDANCE SYSTEM

• US 3,794,272 A
• Filed: 02/13/1967
• Issued: 02/26/1974
• Est. Priority Date: 02/13/1967
• Status: Expired due to Term

• Current Assignee: Klaus J. Hecker
• Original Assignee: Klaus J. Hecker
• Inventors: Hecker, Klaus J.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Birmiel, H. A.
• Application Number:
  US04/616,437
• Time in Patent Office: 2,570 Days
• Field of Search: 343/100.7 235/181 244/3.17
• US Class Current: 244/3.17
• CPC Class Codes: F41G 7/2226 comparing the observed data with stored target data, e.g. target configuration data
• CPC Class Codes: F41G 7/2253 Passive homing systems, i.e. comprising a receiver and do not requiring an active illumination of the target
• CPC Class Codes: F41G 7/2293 using electromagnetic waves other than radio waves

Abstract

The description involves area correlation of a scene viewed by a television (TV) camera carried by a missile toward a target seen preferably in the center of the scene. The initial scene is memorized in an electronic memory circuit of the correlator and digitally correlated with actual video signals viewed by the TV camera in the travel of the missile toward its target, this correlation providing pitch, yaw, roll, and zoom lens scale error signals to correct the missile direction and to correct the zoom lens focus as the target is approached. A reticle is projected onto the camera screen to provide reticle pulses for digital correlation as to scene segments.

Claims

1. An electro-optical guidance system for missiles comprising:

a television camera pickup tube circuit having a scaled zoom lens therefor to record a scene in view and having a video output;

a gyroscopically controlled reticle projected into said television camera pickup tube, said reticle having symmetrical upper and lower reticle lined patterns of three groups of segments juxtaposed to a central lined pattern of three different groups of segments than the pattern lines of said upper and lower patterns to produce reticle pulses on said video output;

a correlator circuit coupled to said video output;

said correlator circuit having a peak detector, a memory circuit, and an averager circuit coupled in common to said video output, said peak detector detecting said reticle pulses on an output thereof coupled in common a pulse pattern recognizer the output of which is connected to a two-bit counter, to said memory circuit to provide readout command signals, to a five-bit digital counter, to said averager circuit, and to a three-bit shift register coupled to receive output signals from said memory circuit, and said correlator further having means to compare the three-bit shift register output with the averager circuit output and apply the compared outputs to an electronic switching means, said electronic switching means being switched by digital address outputs of said five-bit and two-bit counters and said memory circuit being coupled to receive an address from said five-bit and two-bit counters to compare reference voltage amplitude of scene brightness from said memory circuit with actual voltage amplitude of scene brightness from said averager in said means to compare and switching said compared brightness voltage in said electronic switching means to storage means in accordance with the five-bit and two-bit digital counter address output, said storage means having means on its output to relate said stored values to produce pitch, yaw, roll, and scale error voltages for missile guidance to a target in said central pattern of the scene viewed, said scale error voltage being coupled to said scaled zoom lens to maintain scene focus.

2. An electro-optical guidance system for missiles as set forth in claim 1 wherein said means to compare the three-bit shift register output with the averager circuit output includes a comparator circuit on the output of each of the first and third bits of the three-bit shift register as one input thereto, the output of said averager circuit being in common as the second input to each comparator circuit, each comparator circuit having an output.

3. An electro-optical guidance system for missiles as set forth in claim 2 wherein said pulse pattern recognizer having an output connected to said two-bit counter also having a second input coupled to the first digit output of said two-bit counter to feed back digital information of the camera pickup tube scan in the upper, central, and lower patterns.

4. An electro-optical guidance system for missiles as set forth in claim 3 wherein said electronic switching means is constructed and arranged to switch said two comparator circuit inputs in accordance with a sequence established by said five-bit and two-bit counter outputs coupled thereto to said storage means, said storage means being comprised of capacitors to receive plus and minus pitch analog voltage, plus and minus yaw analog voltage, plus and minus roll analog voltage, and plus and minus scale analog voltage.

5. A correlator circuit for an electro-optical guidance system comprising:

an input of video signals from a camera tube of a scene of view on which tube is superimposed a reticle of like upper and lower patterns juxtaposd to an unlike central pattern, each pattern having three groups of eight reticle lines to produce video reticle pulses of greater amplitude than the scene;

a peak detector, a memory circuit, and an amplitude averager circuit coupled in common to said video input, each having outputs;

a pulse pattern recognizer circuit, a five-bit digital counter, a three-bit shift register, said averager, and a READ command input of said memory circuit being coupled in common from the output of said peak detector;

a multiple electronic switch having electrical charge storage means on the output of each switch;

a two-bit digital counter coupled to an output of said pulse pattern recognizer with the digital outputs thereof representative of the upper, lower, and central patterns of said reticle, together with the outputs of said five-bit digital counter, representative of the group in each pattern and the segment between reticle lines in each group, being coupled to the memory address of said memory circuit, said memory circuit having an output coupled to said three-bit shift register to cause each addressed segment of said scene to be shifted through said shift register in accordance with the reticle pulse count of said five-bit and two-bit digital counters, and said output of said two-bit digital counter and the last two higher order digits of said five-bit digital counter being coupled to said multiple electronic switch to switch same in accordance with the existence of the upper, lower, and central reticle patterns;

two comparators, one coupled to the output of the first digit of said three-bit register and the other comparator coupled to the output of the third of said three-bit shift register, the output of each comparator being coupled to said electronic switch, and the output of said averager circuit being coupled as a second input to each comparator to compare actual voltage amplitude of scene segments with scene segments from said memory circuit; and

a weight network coupled to said electrical charge storage means in related combinations to produce analog voltage on outputs thereof to produce pitch, yaw, roll, and scale error voltages.

6. A correlator circuit for an electro-optical guidance system as set forth in claim 5 wherein said coupling from said first and third digit outputs of said three-bit shift register to said two comparators, respectively, each includes a digital-to-analog converter.

7. A correlator circuit for an electro-optical guidance system as set forth in claim 6 wherein said pulse pattern recognizer coupled to said two-bit digital counter has a feedback to said pulse pattern recognizer from the first digit output of said two-bit counter to feedback digital information of the pattern being scanned to enable said pulse pattern recognizer to recognize the next scanned pattern.