SEMICONDUCTOR DEVICE AND CONTROL METHOD

• US 20150367848A1
• Filed: 05/13/2015
• Published: 12/24/2015
• Est. Priority Date: 06/20/2014
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: TERASHIMA, Kazuaki
• Granted Patent: US 9,776,633 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60T 2201/022 Collision avoidance systems
• CPC Class Codes: B60W 2050/0095 Automatic control mode change
• CPC Class Codes: B60W 2540/22 Psychological state; Stress level or workload
• CPC Class Codes: B60W 30/0956 the prediction being responsive to traffic or environmental parameters
• CPC Class Codes: B60W 30/182 Selecting between different operative modes, e.g. comfort and performance modes

Abstract

To achieve an accurate transfer of control from a system to a driver, a semiconductor device includes: a recognition unit that recognizes an object present in the periphery of a vehicle based on a result of observation of the periphery of the vehicle; a route calculation unit that calculates, based on the recognized object, a travel route for the vehicle in an automatic control mode for automatically controlling the vehicle; and a mode control unit that transfers the vehicle from the automatic control mode to a manual control mode for controlling the vehicle according to an operation by a driver, when a travel route to avoid the recognized object cannot be calculated.

Claims

1. A semiconductor device comprising:

a recognition unit that recognizes an object present in the periphery of a vehicle based on a result of observation of the periphery of the vehicle;

a route calculation unit that calculates, based on the recognized object, a travel route for the vehicle in an automatic control mode for automatically controlling the vehicle; and

a mode control unit that transfers the vehicle from the automatic control mode to a manual control mode for controlling the vehicle according to an operation by a driver, when a travel route to avoid the recognized object cannot be calculated.

2. The semiconductor device according to claim 1, wherein the route calculation unit creates, for the recognized object, a map representing an object existing area in which a stationary object is present and an object moving area in which a moving object is likely to move, and calculates a movement route to avoid each of the object existing area and the object moving area on the created map.

3. The semiconductor device according to claim 2, wherein the route calculation unit sets, for each of the object existing area and the object moving area, a probability of existence representing a probability that the object exists, in such a manner that the probability of existence increases as a distance from the vehicle decreases, and calculates a travel route that does not overlap an area in which the probability of existence of the vehicle is equal to or more than a predetermined threshold.

4. The semiconductor device according to claim 2, wherein the route calculation unit sets, for each of the object existing area and the object moving area, a probability of existence representing a probability that the object exists, in such a manner that the probability of existence has a larger value in the object existence area than in the object moving area, and calculates a travel route that does not overlap an area in which the probability of existence of the vehicle is equal to or more than a predetermined threshold.

5. The semiconductor device according to claim 4, wherein the route calculation unit sets, for the object moving area, the probability of existence in such a manner that the probability of existence has a larger value when the moving object is a randomly moving object than when the moving object is a linearly moving object.

6. The semiconductor device according to claim 1, wherein at least a threshold amount of time in advance of a time at which the vehicle is estimated to reach the object, the mode control unit transfers the vehicle from the automatic control mode to the manual control mode, the threshold amount of time including a preparation time defined as a time required for the driver to start operating the vehicle so as to brake the vehicle, and a braking time of the vehicle calculated based on a speed of the vehicle.

7. The semiconductor device according to claim 6, further comprising a friction coefficient calculation unit that calculates a friction coefficient between the vehicle and a road surface based on a distance required for the vehicle to stop from a time when a control for braking the vehicle is started, and on a speed of the vehicle when the control for breaking the vehicle is started,

wherein the mode control unit calculates the braking time of the vehicle based on the calculated friction coefficient and the speed of the vehicle.

8. The semiconductor device according to claim 6, further comprising a stress level calculation unit that calculates a stress level of the driver based on a result of measurement of a state of the driver,

wherein the mode control unit increases the preparation time when the calculated stress level exceeds a predetermined appropriate range.

9. The semiconductor device according to claim 6, further comprising a learning unit that measures a time period from a time when the vehicle is transferred from the automatic control mode to the manual control mode to a time when the driver starts operating the vehicle, and calculates an evaluation value in such a manner that the evaluation value is larger when the measured time period is shorter than the preparation time, than when the measured time period is longer than the preparation time,

wherein the learning unit calculates and updates the preparation time in such a manner that the preparation time increases as the evaluation value decreases.

10. The semiconductor device according to claim 6, further comprising a learning unit that compares an operation of the vehicle by the driver from a time when the vehicle is transferred from the automatic control mode to the manual control mode, with an expected value of the operation, and calculates an evaluation value in such a manner that the evaluation value is larger when the operation and the expected value match, than when the operation and the expected value do not match,

wherein the learning unit calculates and updates the preparation time in such a manner that the preparation time increases as the evaluation value decreases.

11. A control method comprising:

recognizing an object present in the periphery of a vehicle based on a result of observation of the periphery of the vehicle;

calculating a travel route for the vehicle in an automatic control mode for automatically controlling the vehicle based on the recognized object; and

transferring the vehicle from the automatic control mode to a manual control mode for controlling the vehicle according to an operation by a driver, when a travel route to avoid the recognized object cannot be calculated.