1. Field of the Invention
The present invention relates to sighting systems, and more particularly, to boresight harmonization and alignment systems.
2. Brief Description of Related Art
Typically, boresight alignment or harmonization of mounting provisions of a system or component in an aircraft or a land vehicle requires removing the equipment from the aircraft or the land vehicle. Upon completing the harmonization, the harmonized equipment is re-installed and the system undergoes a functional check. The harmonization may be done with multiple adapters with varying degrees of complexity and expends valuable time and resources. The boresight adapters themselves require alignment and calibration, typically involving rigs and elaborate calibration setups.
Further, there may be some additional disadvantages to the traditional boresight alignment systems. These possible disadvantages may include unstable weapon system targeting accuracy, high acquisition and life cycle costs, high failure rate, regular maintenance or calibration checks, lack of built-in-test (hard to determine cause of failure and corrective action), and a large logistic footprint. Current systems may also require a high level of skill and constant training to use. A minimum of two and normally three to five operators are needed and platform systems must often be removed prior to any checks. In addition to the requirement of significant resources and time, the current boresight alignment systems are static and generally do not take airborne structure flexures into account.
Disclosed is a dynamic real-time boresighting system and method. In one embodiment, the method includes obtaining a mapping function by associating deflection and rotation data of strategically located at least two sensors with sensor deflection data, wherein the deflection and rotation data are obtained from the at least two sensors strategically located on a three dimensional (3D) surface model, receiving real-time or static sensor readings from at least two sensors strategically located on a component in an aircraft or a land vehicle, while the aircraft or the land vehicle is moving or static, respectively and determining an alignment of the component by comparing the real-time or static sensor readings obtained from the strategically located at least two sensors with the obtained mapping function.
Further, associating the deflection and rotation data of the strategically located at least two sensors with sensor deflection data includes associating the deflection and rotation data obtained from the at least two sensors which are strategically located on the 3D surface model. The deflection and rotation data of the 3D surface model includes the deflection and rotation data with respect to roll, pitch and yaw of the aircraft or the land vehicle. Furthermore, the 3D surface model is derived using a structural truth model or an existing mathematical model. In addition, the deflection and rotation data of the 3D surface model are determined by applying a predetermined number of known loads on the component. In one embodiment, the 3D surface model is a computer generated model of the aircraft or the land vehicle.
Furthermore, the method includes dynamic real-time or static harmonizing of the component of the aircraft or the land vehicle based on the determined alignment of the component.
In another embodiment, the system includes a dynamic real-time computing system to store a mapping function. Further, the dynamic real-time computing system obtains real-time or static sensor readings from the strategically located at least two sensors on the component while the aircraft or the land vehicle is moving or static, respectively, and the dynamic real-time computing system determines an alignment of the component by comparing the real-time or static sensor readings obtained from the strategically located at least two sensors with the obtained mapping function.
The advantages and features of the present disclosure will become better understood with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:
The exemplary embodiments described herein in detail for illustrative purposes are subject to many variations in structure and design.
The terms, “boresight alignment” and “boresight harmonization” and “harmonization” are used interchangeably throughout the document.
Disclosed is a dynamic real-time boresighting system and method. Dynamic real-time boresighting is required for harmonizing one or more components in an aircraft or land vehicle. In a preferred embodiment, a mathematical surface approximation is used. The mathematical surface approximation includes deriving a 3D surface model of a platform from an existing mathematical model or a structural truth model, acquiring sensor readings from at least two sensors which are strategically located on the 3D surface model of the platform and determining a mapping function that converts real-time or static sensor readings to correspond to deflection and rotation data. Further, real-time or static sensor readings are received from at least two sensors which are strategically located on the component of the aircraft or the land vehicle and an alignment of the component is determined by comparing the real-time or static sensor readings obtained from the strategically located at least two sensors with the obtained mapping function.
In another preferred embodiment, the derived 3D surface model is given predetermined number of loads to determine bending and flexing data. The bending and flexing data obtained upon applying the predetermined number of loads are converted to deflection and rotation data. Further, the mapping function is obtained by associating the converted deflection and deflection data to sensor deflection data obtained from the at least two sensors strategically located on the 3D surface model.
In this embodiment, the at least two sensors are sensor 1110A and sensor 2110B. The at least two sensors sensor 1110A, sensor 2110B are strategically located in/on the component 130 of the aircraft 105. The component 130 in the aircraft 105 includes but not limited to a wing, weapons, an engine, an inertial navigation unit (INU), a gun pod and a radio detection and ranging unit (RADAR).
Moreover, The A/D converter 115 is operatively coupled between the dynamic real-time computing system 120 and the at least two sensors sensor 1110A and sensor 2110B. In one embodiment, the A/D converter 115 converts analog data obtained from the strategically located at least two sensors sensor 1110A and sensor 2110B to digital data and sends the digital data to the dynamic real-time computing system 120.
In one embodiment, the mapping function is obtained by the dynamic real-time computing system 120. The dynamic real-time computing system 120 derives a 3D surface model of the component 130 in the aircraft or the land vehicle using a structural truth model or an existing mathematical model, determines the deflection and rotational data at the strategically located at least two sensors on the 3D surface model by applying a predetermined number of known loads on the component 130 and obtains the mapping function based on the determined deflection and rotation data associated with the strategically located at least two sensors with the sensor deflection data.
In another embodiment, the dynamic real-time computing system 120 determines bending and flexing data associated with the 3D surface model upon applying the predetermined number of loads. The bending and flexing data are then converted to the deflection and rotation data. In addition, the mapping function is used to associate the converted deflection and rotation data to the sensor deflection data obtained from the at least two sensors located on the 3D surface model.
In operation, the dynamic real-time computing system 120 obtains real-time or static sensor readings from the strategically located at least two sensors sensor 1110A and sensor 2110B in/on the component 130 while the aircraft 105 is moving or static, respectively. In one embodiment, the dynamic real-time computing system 120 obtains the real-time sensor readings when the aircraft 105 is moving. In another embodiment, the dynamic real-time computing system 120 obtains the static sensor readings when the aircraft 105 is static. The at least two sensors sensor 1110A and sensor 2110B provide roll, pitch and yaw measurements at the strategically located positions in/on the component 130 of the aircraft 105. The dynamic real-time computing system 120 determines an alignment of the component 130 by comparing the real-time or static sensor readings obtained from the strategically located at least two sensors sensor 1110A and sensor 2110B with the mapping function. Further, the dynamic real-time computing system 120 harmonizes the component 130 of the aircraft 105 based on the determined alignment of the component 130.
In yet another embodiment, the dynamic real-time computing system 120 determines the alignment by calculating an angular deviation by comparing the real-time or static sensor readings obtained from the at least two sensors sensor 1110A, and sensor 2110B with the mapping function.
In yet another embodiment, the strategically located at least two sensors are solid-state “gyro-on-a chip” type of sensors including one micro machined piece of vibrating crystalline quartz tuning fork sensing element that is capable of outputting voltage when rotated about the sensor's input axis. Further, the strategically located at least two sensors are sensor 1110A and sensor 2110B. Alternatively, the strategically located at least two sensors are the sensors on the 3D surface model.
In addition, the voltage outputted from the at least two sensors strategically located on the 3D surface model are converted to the deflection and rotation data and used in the mapping function. For example, the mapping function is stored in form of a lookup table. Moreover, the lookup includes the outputted voltage and corresponding deflection and rotation data.
In yet another embodiment, the sensor 200 is a solid-state “gyro on a chip” (such as 3-axis accelerometers) including one micro machined piece of vibrating crystalline quartz tuning fork sensing element that is capable of outputting voltage when rotated about the sensor's input axis. Further, the sensor 200 has an accuracy that exceeds a required aircraft boresight tolerance of about 2-3 arc minutes.
In yet another embodiment, the sensor 200 is a motion type sensor and the output of the motion type sensor is consistently fed to a dynamic real-time computing system. The sensor 200 is active during the dynamic real-time computing system operation. Therefore, real-time sensor readings are sent to the dynamic real-time computing system, thus reducing dynamic errors that occur during flight.
For instance, the sensor 200 is a direct current (DC) input/high-level DC output device that is fully self-contained, extremely small, and lightweight. Since an inertial sensing element includes just one micro machined piece of crystalline quartz (no moving parts), it can have a virtually unlimited life. The sensor 200 is a mature product that is produced in high volume. The sensor 200 is used on numerous advanced aircrafts, missiles, and space systems. For example, on applying Coriolis Effect, a rotational motion about the sensor's input axis produces a DC voltage output proportional to the rate of rotation. The sensor 200 uses a piezoelectric quartz material that simplifies the active element resulting in stability over temperature and product life. The accuracy of these sensors are typically in the range of about 1.7 to 5 arc seconds and they far exceed the required aircraft boresight tolerance of about 2 to 3 arc minutes.
In another embodiment, determining the deflection and rotational data at the strategically located at least two sensors on the 3D surface model by applying a predetermined number of known loads on the component includes determining bending and flexing data upon applying the predetermined number of known loads on the component. The bending and flexing data are then converted to the deflection and rotation data. The mapping function is used to associate the converted deflection and rotation data to sensor deflection data obtained from the strategically located at least two sensors on the 3D surface model. For example, the mapping function is stored in a lookup table. The lookup table includes the outputted voltage of the at least two sensors and corresponding deflection and rotation data.
At block 410, real-time or static sensor readings are received from at least two sensors strategically located on the component in the aircraft or land vehicle, while the aircraft or the land vehicle is moving or static, respectively. The component of the aircraft includes but not limited to a wing, weapons, an engine, an INU, gun pod, or RADAR unit. In one embodiment, the real-time sensor readings are received when the aircraft is moving. In another embodiment, the static sensor readings are received when the aircraft is static. Further, the at least two sensors provide roll, pitch and yaw measurements at the strategically located positions on the component. For instance, the at least two sensors is placed on the wing of the aircraft for which boresight alignment has to be determined. In such case, the at least two sensors provide roll, pitch and yaw measurements associated to the wing of the aircraft.
At block 415, an alignment of the component is determined by comparing the real-time or static sensor readings obtained from the strategically located at least two sensors with the obtained mapping function. The real-time or static sensor readings are obtained from the at least two sensors that are located on the component of the aircraft. Further, determining the alignment of the component includes calculating an angular deviation by comparing the real-time or static sensor readings obtained from the at least two sensors that are strategically located on the component in the aircraft with the deflection and rotation data in the obtained mapping function.
Furthermore, the method includes dynamic real-time or static harmonizing of the component located in the aircraft or the land vehicle based on the determined alignment of the component.
In a preferred embodiment, the at least two sensors are solid-state “gyro-on-a chip” type of sensors (such as 3-axis accelerometers) including one micro machined piece of vibrating crystalline quartz tuning fork sensing element that is capable of outputting voltage when rotated about the sensor's input axis. Further, the sensor has an accuracy that exceeds a required aircraft boresight tolerance of about 2-3 arc minutes.
Even though the above method and system are described with reference to an aircraft, one can envision using this idea for land vehicles.
The foregoing descriptions of specific embodiments of the present disclosure have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present disclosure and its practical application, to thereby enable others skilled in the art to best utilize the present disclosure and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present disclosure.
This Application claims rights under 35 USC §119(e) from U.S. Application Ser. No. 61/498,710 filed Jun. 20, 2011, and under 35 U.S.C. 119(a)-(d) to Foreign application Serial No 2435/CHE/2012 filed in INDIA entitled “DYNAMIC REAL-TIME BORESIGHTING SYSTEM AND METHOD” filed on Jun. 19, 2012, and the contents of which are incorporated herein by reference.
Number | Date | Country | |
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61498710 | Jun 2011 | US |