Abstract: A crossbow grip guard for preventing the fingers of an associated user from extending above a top portion of a stock of an associated crossbow. The crossbow grip guard may be adapted to be retro-fitted to an existing crossbow and may comprise a main body and an outwardly extending member that extends away from an exterior surface of the main body to create an obstacle or barrier positioned along a length of the main body and is designed to prevent the fingers of the associated user from extending above the top portion of the stock when firing the crossbow.

Abstract: A weapon, such as a crossbow or firearm, may have a main beam, a trigger mechanism mounted to the main beam and, a support rod that can be positioned into a first use position and a second stowed position. The support rod may have a first end used to support the main beam and a second end used to contact a ground surface. In one embodiment, a contact member with a hemispherical contact surface is attached to the second end of the support rod. In another embodiment, the support rod has a handgrip portion that receives a user's hand in supporting the weapon when shooting the weapon when the support rod is in the second stowed position. In still another embodiment, a mounting bracket is used to provide at least two locations for attaching the support rod to the main beam.

Abstract: A device for allowing a crossbow to be released from a drawn position without damaging the crossbow. The device may comprise an elongated member having a substantially cylindrical shape that can be positioned on the upper surface of the barrel of a crossbow. The device may comprise a notched end shaped to receive the bowstring of the crossbow and allows the device to be projected by the bowstring upon actuation of the crossbow's trigger lever.

Abstract: A crossbow having a crossbow grip guard that has a member that extends outwardly in a direction that is substantially perpendicular to the longitudinal axis of the crossbow barrel or stock, and wherein the member extends for a length in a direction that is substantially parallel to the longitudinal axis of the crossbow barrel or stock.

Abstract: A crossbow may include a main beam: (a) a bow assembly including a bow and a bow string adapted to propel an arrow; (b) a trigger mechanism mounted to the main beam; (c) and a bow assembly mounting apparatus for use in selectively mounting the bow assembly at a first location on the main beam to provide a first draw weight and for use in selectively mounting the bow assembly to a second location on the main beam to provide a second draw weight that is substantially different from the first draw weight.

Abstract: A battery-monitoring circuit detects rapid changes in current drawn from a battery by a device powered thereby. The circuit includes calibrating operating modes that determine voltage-to-frequency conversion parameters, and amplifier errors at various levels of battery voltage.

Abstract: A method and system senses the attitude of an accelerating object by measuring acceleration with accelerometers in three orthogonal axes and measuring angular rate with angular rate sensors disposed about each such axis to compute attitude of the object accurately relative to a vertical axis. A processor updates a quaternion representation of attitude based upon the angular rate of the object, and a corrective rate signal is determined from level frame acceleration as a reference for a Kalman filter in calculating the attitude of the object. When velocity or airspeed is available from an external source, an aiding algorithm is employed to provide accurate attitude representations throughout all flight regimes.

Abstract: A plurality of modules interact to form an adaptive network in which each module transmits and receives data signals indicative of radio-frequency identification signals, and indicative of proximity sensing at the module. A central computer accumulates the data produced or received and relayed by each module for analyzing inventory, pricing and customer responses to transmit through the adaptive network signals representative of information to be displayed at selectively-addresses modules in response to computer analyses of the data accumulated from modules forming an adaptive network.

Abstract: A method and system senses the attitude of an accelerating object by measuring acceleration with accelerometers in three orthogonal axes and measuring angular rate with angular rate sensors disposed about each such axis to compute attitude of the object accurately relative to a vertical axis. A processor updates a quaternion representation of attitude based upon the angular rate of the object, and a corrective rate signal is determined from level frame acceleration as a reference for a Kalman filter in calculating the attitude of the object. When velocity or airspeed is available from an external source, an aiding algorithm is employed to provide accurate attitude representations throughout all flight regimes.

Abstract: A method and system updates a network of sensors remotely through the use of a communication link. The sensors to be updated as well as data files to perform the updating are selected at a base station. The selected sensors are notified of the upcoming update by the base station and may accept or reject the update. The sensors that approve the update then receive data files through the communication link. The sensors notify the base station of any missing data files, which are then retransmitted to all sensors that may be missing data files from the first transmission. After the sensors receive all data files, the update is initiated.

Abstract: A method and system senses the attitude of an accelerating object by measuring acceleration with accelerometers in three orthogonal axes and measuring angular rate with angular rate sensors disposed about each such axis to compute attitude of the object accurately relative to a vertical axis. A processor updates a quaternion representation of attitude based upon the angular rate of the object, and a corrective rate signal is determined from level frame acceleration as a reference for a Kalman filter in calculating the attitude of the object.

Abstract: A method and system attitude of an accelerating object by measuring acceleration with accelerometers in three orthogonal axes and measuring angular rate with angular rate sensors disposed about each such axis to compute attitude of the object accurately relative to a vertical axis. A processor updates a quaternion representation of attitude based upon the angular rate of the object, and a corrective rate signal is determined from level frame acceleration as a reference for a Kalman filter in calculating the attitude of the object.

Abstract: A method and system senses the attitude of an accelerating object. Attitude sensing is accomplished by measuring acceleration in three orthogonal axes and measuring angular rate about each such axis to compute attitude accurately relative to a vertical axis. The system includes accelerometers and angular rate sensors for sensing the acceleration and the angular rate, respectively, of the object. A processor updates a quarternion representation of attitude based upon the angular rate of the object and a corrective rate signal to obtain the attitude of the object. Temperature compensation and frequency compensation may also be performed to update the quarternion.

Abstract: Crossbow bowstring drawing mechanisms which are integrated into or secured in the crossbow handle and which provide a straight and balanced draw to the crossbow bowstring to cock the crossbow bowstring in position in the crossbow trigger mechanism ready for firing. The cocking system can be manually operated or motorized, and can be manufactured as part of a crossbow or retrofit into a crossbow. An internal or external source of rotational power, such as hand crank, power screwdriver or an electrical motor, is preferably utilized in conjunction with a claw member including a bowstring engaging portion to translate rotation of the input source to longitudinal movement of the claw member to draw or release the crossbow bowstring resulting with minimal effort being expended by the user.

Abstract: A three-dimensional position and orientation tracking system uses accelerometers to measure acceleration of a moveable object (e.g., a head-mounted display unit or a data glove). A tracking processor generates both position and orientation information on the object relative to a simulation environment as a function of the acceleration data. In one embodiment, a simplified radar-based tracking system is disposed relative to the object and periodically provides additional tracking data on the object to the tracking processor. The tracking processor uses the additional data to correct the position and orientation information using a feedback filter process. The position and orientation information signals generated can be used, for example, in a simulation or virtual reality application. Position and orientation information is received by a simulation processor relative to the object. The simulation processor modifies a simulation environment as a function of the position and orientation information received.

Abstract: A three-dimensional position and orientation tracking system uses accelerometers to measure acceleration of a moveable object (e.g., a head-mounted display unit or a data glove). A tracking processor generates both position and orientation information on the object relative to a simulation environment as a function of the acceleration data. In one embodiment, a simplified radar-based tracking system is disposed relative to the object and periodically provides additional tracking data on the object to the tracking processor. The tracking processor uses the additional data to correct the position and orientation information using a feedback filter process. The position and orientation information signals generated can be used, for example, in a simulation or virtual reality application. Position and orientation information is received by a simulation processor relative to the object. The simulation processor modifies a simulation environment as a function of the position and orientation information received.