| CPC B60W 40/08 (2013.01) [B60W 2040/0881 (2013.01); B60W 2554/20 (2020.02)] | 15 Claims |
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1. A physique estimation device comprising:
a sensor having a transmission antenna to transmit a transmission wave comprising multiple chirps whose frequencies rise or fall, a reception antenna to receive the transmission wave reflected by multiple targets in a vehicle cabin as a received wave, and a mixer to mix the transmission wave and the received wave to generate beat signals; and
processing circuitry
to acquire position information about a reflection point where the transmission wave is reflected, using the received wave and analyzing the beat signals; and
to estimate a physique of a non-static object present in the vehicle cabin using the position information, wherein
the processing circuitry determines a movable body occupancy probability showing a probability of presence of a non-static object in each of multiple cells contained in three-dimensional grid space and showing an inside of the vehicle cabin, and estimates a spatial extent of cells whose movable body occupation probabilities are greater than or equal to a threshold as the physique of the non-static object present in the vehicle cabin, and wherein
the processing circuitry is further configured:
to determine whether a detected target is a non-static object or a static object;
to,
when a non-static object is detected in a case where either multiple non-static objects or at least one non-static object and at least one static object are detected as the multiple targets, set a temporary movable body occupancy probability of one or more cells corresponding to a position of the detected non-static object to a value close to 1, set a temporary movable body occupancy probability of each cell at a position between the position of the detected non-static object and the sensor to a value which asymptotically varies to 0 with distance from the position of the detected non-static object toward the sensor, and set a temporary movable body occupancy probability of each cell at a position which is away from the position of the non-static object when viewed from the sensor to 0.5,
when a static object is detected in the above case, set a temporary movable body occupancy probability of each of one or more cells corresponding to a position of the detected static object, and a temporary movable body occupancy probability of each cell which is away from the position of the detected static object when viewed from the sensor to 0.5, and set a temporary movable body occupancy probability of each cell at a position between the position of the detected static object and the sensor to a value which asymptotically varies to 0 with distance from the position of the detected static object toward the sensor,
when multiple non-static objects are detected in the above case, determine a product of one or more temporary movable body occupation probabilities which are set when a non-static object is detected for each of the cells, to update it as a new temporary movable body occupancy probability of the cell, or
when at least one non-static object and at least one static object are detected in the above case, determine a product of one or more temporary movable body occupation probabilities which are set when a non-static object is detected and one or more temporary movable body occupation probabilities which are set when a static object is detected for each of the cells, and to calculate the product as a new temporary movable body occupancy probability of the cell;
to determine, as to the movable body occupancy probability of each of the cells, a weighted average of the movable body occupancy probability in measurement cycles containing up to an immediately preceding measurement cycle and the temporary movable body occupancy probability in a current measurement cycle as the movable body occupancy probability in measurement cycles containing up to the current measurement cycle; and
to assign the movable body occupancy probability in the measurement cycles containing up to the current measurement cycle to each of the cells as the movable body occupancy probability, and generate an occupancy grid map.
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