Velocity sensor and ground vehicle velocity sensor using the same
AssigneeHitachi, Ltd.
InventorsToshiyuki Nagasaku, Hiroshi Kondoh, Hiroshi Shinoda
Life of this patent
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Abstract
There is provided a highly accurate velocity sensor having a reduced detection error. A sensor circuit unit generates an electromagnetic wave and emits it from a transmission antenna. Furthermore, a reception antenna receives a reflection wave from the ground and a mixer mixes it with a local signal, thereby generating a low-frequency signal. The electromagnetic wave emitted from the sensor circuit unit shapes a beam by a dielectric lens before emitting it toward the ground. Here, the beam shape is such that the beam width in the vicinity of the sensor is smaller than the beam width in the vicinity of the ground.
Claims36
A velocity sensor configured so as to be installed on an movable body for emitting a transmission signal having wave characteristics, receiving a reflection signal of the transmission signal reflected from an object, and generating and outputting a signal required for calculating a relative speed between said movable body and said object according to the reflection signal received and the transmission signal,
- wherein the transmission signal forms a beam shape, which is formed with a beam width in the vicinity of the object almost identical to or smaller than the beam width in the vicinity of an emission opening of said velocity sensor for emitting the transmission signal, and
- the transmission signal is emitted from the emission opening in the direction defining a predetermined angle with the relative speed direction of said movable body with respect to said object, the predetermined angle being an arbitrary angle greater than 0 degrees and smaller than 90 degrees or greater than 90 degrees and smaller than 180 degrees.
A velocity sensor configured so as to be installed on an movable body and comprising:
- a sensor circuit unit for generating a transmission signal having wave characteristics, receiving a reflection signal of the transmission signal reflected from an object, and generating and outputting a signal required for calculating a relative speed between said movable body and said object according to the reflection signal received and the transmission signal, and
- a lens for modifying the irradiation angle of the transmission signal generated by the sensor circuit unit,
- wherein the transmission signal forms a beam shape, which is formed with a beam width in the vicinity of said object almost identical to or smaller than the beam width in the vicinity of an emission opening of said velocity sensor for emitting the transmission signal, and
- said transmission signal is emitted from the emission opening in the direction defining a predetermined angle with the relative speed direction of said movable body with respect to said object, the predetermined angle being an arbitrary angle greater than 0 degrees and smaller than 90 degrees or greater than 90 degrees and smaller than 180 degrees.
A ground vehicle velocity sensor for detecting a ground travelling speed of a vehicle travelling on a ground and having a beam generation unit attached to it, according to frequency of a beam emitted from the beam generation unit toward the ground and frequency of a reflection beam generated from the beam reflected from the ground,
- wherein the beam has such a shape that the beam width in the vicinity of the ground is almost identical or smaller than the beam width in the vicinity of an emission opening of said beam generation unit for emitting the beam, and
- the beam is emitted from the emission opening in the direction defining a predetermined angle with the relative speed direction of said vehicle with respect to said ground, the predetermined angle being an arbitrary angle greater than 0 degrees and smaller than 90 degrees or greater than 90 degrees and smaller than 180 degrees.
Dependencies are inferred from the claim text.