Velocimeter for determining the maximum or minimum relative velocity between two bodies

Claim 5

The method of claim 2 comprising determining the duration of the intervals of time by a stable frequency source, and multiplying the count retained to provide an indication of the maximum radial relative velocity in terms of prescribed units of velocity.

Claim 6

The method of claim 3 wherein the locus of one object relative to the other and its acceleration are known to a reasonable degree of accuracy, computing a multiplying factor and an addition factor based on the locus and acceleration, and modifying the retained count by said factors to provide a result which is an indication of the actual relative velocity which exists between the two objects at some predetermined relative position.

Claim 7

The method of claim 2 comprising supplying the Doppler signal to a phase locked loop consisting of a phase comparator and a voltage conrolled oscillator which is made to oscillate at a frequency which is an exact multiple of the frequency of the Doppler signal, dividing the frequency of the oscillator and supplying the same as the second input to the phase comparator, controlling the frequency of the oscillator by the output of the phase comparator and counting the output of the oscillator in lieu of the Doppler signal itself to increase the sensitivity and accuracy.

Claim 8

The method of claim 5 comprising determining the duration of the intervals of time by a stable frequency source, and multiplying the count retained to provide an indication of the maximum radial relative velocity in terms of prescribed units of velocity.

Claim 9

The method of claim 6 wherein the locus of one object relative to the other and its acceleration are known to a reasonable degree of accuracy, computing a multiplying factor and an addition factor based on the locus and acceleration, and modifying the retained count by said factors to provide a result which is an indication of the actual relative velocity which exists between the two objects at some predetermined relative position.

Claim 10

The method of claim 5 comprising signalling the correctness of the indication of maximum relative velocity by a monitor circuit which determines whether the output of the voltage controlled oscillator has remained in phase with the Doppler signal for the interval of time in which the highest count was obtained, the last preceding interval of time and the first subsequent interval of time.

Claim 11

The method of claim 8 comprising determining the duration of the intervals of time by a stable frequency source, and multiplying the count retained to provide an indication of the maximum radial relative velocity in terms of prescribed units of velocity.

Claim 12

The method of claim 9 wherein the locus of one object relative to the other and is acceleration are known to a reasonable degree of accuracy, computiNg a multiplying factor and an addition factor based on the locus and acceleration, and modifying the retained count by said factors to provide a result which is an indication of the actual relative velocity which exists between the two objects at some predetermined relative position.

Claim 13

The method of claim 10 wherein one of said objects is a gun and the other of said objects is a shell, the transmitter and receiver being fixed in relation to the gun, the multiplying factor and addition factor being such that the result is an indication of the muzzle velocity of the shell in prescribed units of velocity.

Claim 14

The method according to claim 11 wherein the result is stored in a memory and the counting is automatically reset after completion of the multiplying and adding such that the muzzle velocity of a subsequent may be determined.

Claim 15

The method according to claim 12 comprising averaging the results over a number of shells fired and using the result of this averaging to indicate the average muzzle velocity of the shells so averaged.

Claim 16

Apparatus for measuring maximum relative velocity between two bodies as measured radially from one of the bodies, said apparatus comprising a transmitter/receiver means on one of said bodies for measuring frequency which is proportional to the relative velocity between the two bodies by means of the Doppler principle, an amplifier connected to the transmitter/receiver means to receive the said Doppler signal therefrom, a phase locked loop connected to said amplifier to receive the amplified Doppler signal therefrom, said phase locked loop comprising a phase comparator connected to the amplifier, a voltage controlled oscillator having an input connected to the output of the comparator and which is made to oscillate at a frequency which is an exact multiple of the frequency of the Doppler signal, and a divider unit having an input connected to the output of the oscillator and an output connected to the comparator, a digital frequency counting system coupled to said phase comparator and comprising a clock signal gate, and a counter connected to said gate for receiving signals from said phase comparator and constructed to retain only the maximum count, said counter comprising a pair of counter units successively fed with the Doppler signal wherein a change in the count at any one time period results in an exceeded count in one time interval indicating a maximum condition.

Claim 17

Apparatus for measuring maximum relative velocity between two bodies as measured radially from one of the bodies, said apparatus comprising a transmitter/receiver means on one of said bodies for measuring frequency which is proportional to the relative velocity between the two bodies by means of the Doppler principle, an amplifier connected to the transmitter/receiver means to receive the said Doppler signal therefrom, a phase locked loop connected to said amplifier to receive the amplified Doppler signal therefrom, said phase locked loop comprising a phase comparator connected to the amplifier, a voltage controlled oscillator having an input connected to the output of the comparator and which is made to oscillate at a frequency which is an exact multiple of the frequency of the Doppler signal, and a divider unit having an input connected to the output of the oscillator and an output connected to the comparator, a digital frequency counting system coupled to said phase comparator and comprising a clock signal gate, and a counter connected to said gate for receiving signals from said phase comparator and constructed to retain only the maximum count, said counter comprising a pair of counter units successively fed with the Doppler signal wherein a change in the count at any one time period results in an exceeded count in one time interval indicating a maximum condition.

Claim 18

A device according to claim 14 comprising a reject logc monitoring means coupled to the phase comparator and clock for determining if the registered maximum number of cycles counted is a correct value.

Claim 19

A device according to claim 28 comprising a delay means inserted between said phase comparator and said reject logic monitoring means for allowing short interruptions of the Doppler signal without causing rejection of the measurement.