Combined laser/FLIR optics system

A targeting and imaging system comprising:

• a forward-looking infrared (FLIR) optical system for receiving infrared (IR) energy from an area of interest (AOI);
• a FLIR optical imager for generating an IR image with the IR energy received from the AOI, wherein said FLIR optical imager is arranged to receive said IR energy from the FLIR optical system;
• a laser transmitter;
• a laser receiver;
• and
• laser optics for directing laser energy from said laser transmitter to a desired target located in the AOI, and for directing laser energy returning from the desired target in the AOI to said laser receiver,
• wherein said FLIR optical system and said laser optics share a common pitch bearing, such that all optical elements individually subject to pitch rotations are commonly shared by said FLIR optical system and said laser optics.

A targeting and imaging system comprising:

• forward-looking infrared (FLIR) optics for steering an infrared (IR) line-of-sight (LOS) towards a desired area of interest (AOI), for receiving IR energy from the AOI, for focusing the IR energy, and for generating an optical image of the AOI;
• a laser transmitter;
• a laser range receiver (LRR);
• a laser spot tracker (LST);
• and
• laser optics means for steering a laser LOS, such that the transmitter laser energy illuminates at least a portion of the AOI, for receiving laser energy, and for directing the received laser energy into the LRR and the LST,
• wherein said FLIR optics means and said laser optics means share a single pitch bearing, and
• wherein the IR energy and the laser energy pass through a common aperture.

A method of isolating an electrical fault in a servo system comprising a servo motor, said method comprising the steps of:

• (a) generating a first current activation signal;
• (b) activating a first current control means for conducting current in a first direction through a winding in the servo motor in response to the first current activation signal independent of servo motor shaft position;
• (c) generating a second current activation signal;
• (d) activating a second current control means for conducting current in a second direction through the winding in the servo motor in response to the second current activation signal independent of servo motor shaft position;
• and
• (e) determining whether a fault exists as a function of an amount of current flowing into and out of the first and the second current control means.

A method of isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said method comprises the steps of:

• (a) generating a first current command;
• (b) activating a current control means for conducting current in a first direction through a motor winding in response to the first current command independent of servo motor shaft position;
• (c) determining whether an amount of current flowing into the first current control means is greater than a predefined threshold;
• (d) determining whether the amount of current flowing out of the first current control means is zero;
• (e) generating a second current command;
• (f) activating a second current control means for conducting current in a second direction through the motor winding in response to the second current command independent of servo motor shaft position;
• (g) determining whether an amount of current flowing into the second current control means is greater than the predefined threshold;
• (h) determining whether the amount of current flowing out of the second current control means is zero;
• (i) determining whether an electrical fault has occurred in the amplifier or whether an electrical fault has occurred in the motor winding as a function of the amount of current flowing into and out of the first and the second current control means.

A method of isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said method comprising the steps of:

• (a) generating an activation signal for a pair of drive transistors which controls current flow in a first direction through a winding in the multi-phase motor, said pair of drive transistors comprising an upper drive transistor and a lower drive transistor;
• (b) determining whether an amount of current flowing through the upper drive transistor is greater than a predefined threshold;
• (c) determining whether an amount of current flowing through the lower drive transistor is zero;
• (d) generating an activation signal for a second pair of drive transistors which controls current flow in a second direction through the winding in the multi-phase motor, said second pair of drive transistors comprising a second upper drive transistor and a second lower drive transistor;
• (e) determining whether an amount of current flowing through the second upper drive transistor is greater than a predefined threshold;
• (f) determining whether an amount of current flowing through the second lower drive transistor is zero;
• and
• (h) determining the electrical fault condition as a function of the amount of current flowing through the upper drive transistor and lower drive transistor for each drive transistor pair.

A method of determining a fault to be an electrical fault in a servo system comprising a servo motor and a linear amplifier, said method comprising the steps of:

• (a) determining an amount of source current applied to a first linear amplifier and a second linear amplifier, wherein said first and said second linear amplifiers are connected to opposing ends of a single motor winding;
• (b) generating a first voltage command such that the first linear amplifier generates more voltage than the second linear amplifier;
• (c) determining an amount of current flowing out of the second linear amplifier;
• (d) generating a second voltage command such that the second linear amplifier generates more voltage than the first amplifier;
• (e) determining an amount of current flowing out of the first linear amplifier;
• and
• (f) isolating the electrical fault as a function of said amount of current flowing out of the first linear amplifier, the amount of current flowing out the second linear amplifier, and the amount of source current.

An apparatus for isolating an electrical fault in a servo system comprising a servo motor, said apparatus comprising:

• first control means for generating a first current activation signal;
• means for driving current in a first direction through a winding in the servo motor, responsive to said first current activation signal;
• second control means for generating a second current activation signal;
• means for driving current in a second direction through the winding in the servo motor, responsive to said means for generating a second current activation signal;
• means for determining whether a fault exists as a function of an amount of current flowing into and out of said means for driving the first current and said means for driving the second current.

An apparatus for isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said apparatus comprising:

• means for generating a first current command;
• means for conducting current in a first direction through a motor winding, wherein said means for conducting a first current is responsive to the first current command;
• means for determining whether an amount of current flowing into said means for conducting the first current is greater than a predefined threshold;
• means for determining whether the amount of current flowing out of said means for conducting the first current is zero;
• means for generating a second current command;
• means for conducting current in a second direction through the motor winding, wherein said means for conducting the second current is responsive to the second current command;
• means for determining whether an amount of current flowing into said means for conducting the second current is greater than the predefined threshold;
• means for determining whether the amount of current flowing out of said means for conducting the second current is zero;
• means for determining whether an electrical fault has occurred in the amplifier or whether an electrical fault has occurred in the motor winding as a function of the amount of current flowing into and out of said means for conducting the first current and said means for conducting the second current.

An apparatus for isolating an electrical fault in a servo system comprising a servo motor and an amplifier, said apparatus comprising:

• control logic means for generating an activation signal for a pair of drive transistors which control current flow in a positive direction through a motor winding, said pair of drive transistors comprising an upper drive transistor and a lower drive transistor;
• means for determining whether an amount of current flowing into the upper drive transistor is greater than a predefined threshold;
• means for determining whether an amount of current flowing into the lower drive transistor is zero;
• control logic means for generating an activation signal for a second pair of drive transistors which control current flow in a negative direction through the motor winding, said second pair of drive transistors comprising a second upper drive transistor and a second lower drive transistor;
• means for determining whether an amount of current flowing into the second upper drive transistor is greater than a predefined threshold;
• means for determining whether an amount of current flowing into the second lower drive transistor is zero;
• and
• means for determining the electrical fault condition as a function of the amount of current flowing into the upper drive transistor and lower drive transistor for each drive transistor pair.

An apparatus for isolating an electrical fault in a servo system comprising a servo motor and a linear amplifier, said apparatus comprising:

• supply current sensing means for determining an amount of supply current applied to a first linear amplifier and a second linear amplifier, wherein said first and said second linear amplifiers are connected to opposing ends of a motor winding;
• control means for generating a first voltage command such that the first linear amplifier generates more voltage than the second linear amplifier;
• current sensing means for determining an amount of current flowing out of the second linear amplifier;
• control means for generating a second voltage command such that the second linear amplifier generates more voltage than the first amplifier;
• current sensing means for determining an amount of current flowing out of the first linear amplifier;
• and
• logic means for determining the electrical fault, without a test load and a test load relay, as a function of the amount of current flowing out of the first linear amplifier, the amount of current flowing out the second linear amplifier, and the amount of source current.

A method of sharpening the contrast of an input digital image comprising an array of pixel values, said method comprising the steps of:

• extracting a low frequency digital image from the input digital image, said low frequency digital image comprising an array of pixel values;
• extracting a high frequency digital image from the input digital image, said high frequency digital image comprising an array of pixel values;
• determining a difference value between adjacent pixels along each row of the input digital image;
• determining a contrast measure for the input digital image by summing the difference values;
• adjusting a low frequency digital image gain to high frequency digital image gain ratio as a function of said contrast measure;
• and
• combining each pixel value in the low frequency digital image with a corresponding pixel value in the high frequency digital image.

In an imaging system comprising a number “n” of analog-to-digital converters (ADCs), wherein each of the “n” ADCs converts every nth row or nth column of analog image data into digital image data, a method of removing ADC offset pattern differences from a digital image comprising the steps of:

• generating “n” histograms, wherein each of the “n” histograms reflects a dynamic range of pixel values produced by a corresponding one of said “n” ADCs;
• adjusting a pixel offset coefficient for each pixel associated with one of said “n” ADCs as a function of the dynamic range of the corresponding histogram;
• and
• removing ADC offset pattern differences by adjusting each pixel value associated with said one of said “n” ADCs as a function of the corresponding, adjusted pixel offset coefficient.

A method of enhancing a portion of a digital image comprising an array of pixel values, said method comprising the steps of:

• extracting a desired portion of the digital image;
• horizontally shifting the desired portion of the digital image by an amount equal to a fraction of a pixel width;
• integrating the desired portion of the digital image with the horizontally shifted portion of the digital image to produce a first image field;
• vertically shifting the desired portion of the digital image by a fraction of a pixel height,
• horizontally shifting the vertically shifted portion of the digital image by the same fraction of a pixel width;
• integrating the vertically shifted portion of the digital image with the vertically and horizontally shifted portion of the digital image to produce a second image field;
• and
• interleaving the first image field and the second image field.

A method of focusing an image in an optical imaging system comprising a focus target, an optical focusing element and an array of detector elements, said method comprising the steps of:

• adjusting the optical focusing element a plurality of times;
• illuminating the array of detector elements with a high frequency test pattern after adjusting the optical focusing element, such that a random phase relationship exists between the test pattern and the array of detector elements;
• converting the value associated with each detector element to a corresponding digital word;
• generating a contrast measure after adjusting the optical focusing element based on the digital words;
• and
• generating an optical focusing element control signal for controlling the adjustment of the optical focusing element as a function of a peak contrast measure.

An apparatus for sharpening the contrast of an input digital image comprising an array of pixel values, said apparatus comprising:

• means for extracting a low frequency digital image from the input digital image;
• means for extracting a high frequency digital image from the input digital image;
• means for determining a difference value between adjacent pixels along each row of the input digital image;
• means for determining a contrast measure for the input digital image by summing the difference values;
• means for adjusting a low frequency digital image gain to high frequency digital image gain ratio as a function of said contrast measure;
• and
• means for combining the low frequency digital image with the high frequency digital image.

In an imaging system comprising a number “n” of analog-to-digital converters (ADCs), wherein each of the “n” ADC converts every nth row or nth column of analog image data into digital image data, an apparatus for removing ADC offset pattern differences from a digital image comprising:

• means for generating “n” histograms, wherein each of the “n” histograms reflects a dynamic range of pixel values produced by a corresponding one of said “n” ADCs;
• means for adjusting a pixel offset coefficient for each pixel associated with one of said “n” ADCs as a function of the dynamic range of the corresponding histogram;
• and
• means for removing ADC offset pattern differences by adjusting each pixel associated with said one of said “n” ADCs as a function of the corresponding adjusted pixel offset coefficient.

An apparatus for enhancing a portion of a digital image comprising:

• windowing means for extracting a desired portion of an input digital image;
• means for horizontally shifting the desired portion of the input image by an amount equal to a fraction of a pixel width, and
• means for generating a first image field by integrating the desired portion of the input image with the horizontally shifted portion of the input image;
• means for vertically shifting the desired portion of the input image by the same fraction of a pixel height,
• means for horizontally shifting the vertically shifted portion of the input image by the same fraction of a pixel height, and
• means for generating a second image field by integrating the vertically shifted portion of the input image with the vertically and horizontally shifted portion of the input image;
• and
• means for interleaving the first image field and the second image field.

An apparatus for focusing an image in an optical imaging system comprising an optical focusing element and an array of detector elements, said apparatus comprising:

• means for adjusting the optical focusing element a plurality of times;
• means for illuminating the array of detector elements with a high frequency test pattern after adjusting the optical focusing element, wherein a random phase relationship exists between the test pattern and the array of detector elements;
• analog-to-digital conversion means for converting the value associated with each detector element to a corresponding digital word;
• means for generating a peak contrast measure after adjusting the optical focusing element based on the digital words;
• and
• means for generating an optical focusing element control signal which controls said means for adjusting the optical focusing element as a function of a peak contrast measure.

An optical image system comprising:

• a housing assembly;
• a window associated with said housing assembly, through which optical energy passes;
• and
• an electromagnetic interference grid for transmitting on-axis optical energy through the window and for radially diffracting off-axis electromagnetic interference, wherein said electromagnetic interference grid is integrated into said window, and wherein said electromagnetic interference grid comprises an array of circular grid elements aligned in rows and columns.

A method of aligning first radiation from a first source with second radiation from a second source, said method comprising the steps of:

• aligning the first radiation with a plurality of openings in a reticle pattern, said plurality of openings being spaced away from a centrally located opening;
• projecting said second radiation through an opening in the reticle pattern, wherein the opening has lateral edges that project radially inward toward the centrally located opening;
• translating a path of said second radiation until it is coincident with a lateral edge;
• and
• translating said path toward the centrally located opening along the lateral edge toward the centrally located opening.

In a forward-looking infrared (FLIR)/laser based optical imaging system, a method of aligning IR line-of-sight (LOS) and laser LOS comprising the steps of:

• projecting infrared (IR) energy from an IR energy source through a reticle pattern onto a focal plane array;
• aligning the IR LOS such that a maximum amount of IR energy passes through a plurality of peripheral openings in the reticle pattern, wherein the peripheral openings are of equal distance from a centrally located opening;
• projecting laser energy from a laser transmitter through one of a plurality of wedge-shaped openings in the reticle pattern, wherein each of the wedge-shaped openings has lateral edges that project radially inward toward the centrally located opening;
• translating the laser LOS until it is coincident with a lateral edge;
• and
• translating the laser LOS toward the centrally located opening along the lateral edge.

In an optical system that employs at least two energy sources, an apparatus for aligning a first energy source with a second energy source, said apparatus comprising:

• means for aligning the first energy source with a plurality of openings in a reticle pattern such that said plurality of openings in the reticle pattern are of equal distance from a centrally located opening;
• means for projecting energy from the second energy source through an opening in the reticle pattern, wherein the opening has lateral edges that project radially inward toward the centrally located opening;
• means for translating the energy from the second energy source until it is coincident with a lateral edge;
• and
• means for translating said energy toward the centrally located opening along the lateral edge.

In a forward-looking infrared (FLIR)/laser based optical imaging system, an apparatus for boresighting IR line-of-sight (LOS) and laser LOS comprises:

• IR energy source means for projecting infrared (IR) energy through a reticle pattern onto a focal plane array;
• IR optics means for aligning the IR LOS such that a maximum amount of IR energy passes through a plurality of peripheral openings in the reticle pattern, wherein the peripheral openings are of equal distance from a centrally located opening;
• laser transmitter means for projecting laser energy through one of a plurality of wedge-shaped openings in the reticle pattern, wherein each of the wedge-shaped openings has lateral edges that project radially inward toward the centrally located opening;
• laser optics means for translating the laser LOS until it is coincident with a lateral edge;
• and
• laser optics means for translating the laser LOS toward the centrally located opening along the lateral edge.