Vehicle movement estimation device and vehicle movement estimation method
A vehicle movement estimation device has a radar that is provided in a vehicle and that performs transmission of a radar wave and reception of a reflected wave that is the radar wave reflected by an object, a radar movement estimator that estimates a radar movement velocity and a radar movement direction of the radar based on the received reflected wave, an angular velocity estimator that estimates a rotational angular velocity of the vehicle, and a vehicle movement estimator that estimates a movement velocity and a movement direction of a prescribed position of the vehicle based on the estimated radar movement velocity and radar movement direction, the estimated rotational angular velocity, and a spatial relationship between the radar and the prescribed position.
1. A vehicle movement estimation device comprising:
two radar devices, which, in operation, transmit radar waves and receives reflected waves that are the radar waves reflected by objects, the two radar devices configured to be provided at different positions on a vehicle;
a radar movement estimator, which, in operation, estimates respective radar movement velocities and respective radar movement directions of the two radar devices based on the reflected waves;
an angular velocity estimator, which, in operation, estimates a rotational angular velocity of the vehicle based on the respective radar movement velocities and the respective radar movement directions of the two radar devices and a distance between the two radar devices; and
a vehicle movement estimator, which, in operation, estimates a movement velocity and a movement direction of a prescribed position of the vehicle based on the respective radar movement, velocities, the respective radar movement directions, the rotational angular velocity, and spatial relationships between the two radar devices and the prescribed position.
2. The vehicle movement estimation device according to claim 1 , further comprising:
an information storage, which, in operation, stores arrangement information which indicates relative positions of the two radar devices with respect to the prescribed position.
3. The vehicle movement estimation device according to claim 1 , wherein
the two radar devices are provided in different positions which can be at least described in a plane that is parallel to a road surface,
the arrangement information indicates the relative positions at least in the plane that is parallel to the road surface,
the radar movement estimator estimates the respective radar movement velocities and the respective radar movement directions of the two radar devices in the plane that is parallel to the road surface, and
the angular velocity estimator estimates the rotational angular velocity in the plane that is parallel to the road surface.
4. The vehicle movement estimation device according to claim 3 , wherein the prescribed position is a position that corresponds with a middle point between a left rear wheel and a right rear wheel of the vehicle in the plane which is parallel to the road surface.
5. The vehicle movement estimation device according to claim 1 , wherein
the two radar devices include a first radar device and a second radar device,
the first radar device is provided in a left front portion of the vehicle, and a viewing angle of the first radar device includes a portion on a left side of the vehicle,
the second radar device is provided in a right front portion of the vehicle, and a viewing angle of the second radar device includes a portion on a right side of the vehicle.
6. The vehicle movement estimation device according to claim 1 , wherein:
the two radar devices are provided in a left portion of the vehicle, and viewing angles of the two radar devices include a left direction of the vehicle; or
the two radar devices are provided in a right portion of the vehicle, and the viewing angles of the two radar devices include a right direction of the vehicle.
7. A vehicle movement estimation method comprising:
performing, by two radar devices that are provided at different positions on a vehicle, transmissions of radar waves and receptions of reflected waves that are the radar waves reflected by objects;
estimating respective radar movement velocities and respective radar movement directions of the two radar devices based on the reflected waves;
estimating a rotational angular velocity of the vehicle based on the respective radar movement velocities and the respective radar movement directions of the two radar devices and a distance between the two radar devices; and
estimating a movement velocity and a movement direction of a prescribed position of the vehicle based on the respective radar movement velocities, the respective radar movement directions, the rotational angular velocity, and spatial relationships between the two radar devices and the prescribed position.