Vehicle control system

A vehicle control system is provided to allow an autonomous vehicle to promptly launch after picking up a passenger. A controller comprises a drive controller for controlling a drive motor, and electric power is supplied to the drive motor from a power source. A main switch is manipulated by the controller to selectively connect and disconnect the drive controller to/from the power source. The controller is configured to propel the vehicle autonomously to a pickup location to pick up a passenger, and to turn on the main switch if the passenger is detected within a predetermined area at the pickup location.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention claims the benefit of priority to Japanese Patent Application No. 2016-167748 filed on Aug. 30, 2016 with the Japanese Patent Office, the entire contents of which are incorporated herein by reference in its entirety.

BACKGROUND

Field of the Invention

Embodiments of the present disclosure relate to the art of a vehicle control system configured to operate the vehicle autonomously.

Discussion of the Related Art

JP-A-2014-106854 describes an automatic driving vehicle control apparatus for operating vehicles autonomously without a driver. The control system of this kind requires a considerable electricity to carry out calculations. For this reason, it is preferable to apply the control system of this kind to a vehicle having a motor serving not only as a prime mover but also as a power source.

The vehicle to which the control system of this kind may travel autonomously without requiring a driver to a point to pick up a passenger while manipulating a steering device, an accelerator and so on by a controller. In the vehicle of this kind, standby electricity required by the controller may be reduced by cutting electricity to the controller after arriving at the pickup location. However, if the controller is shut-down, it will take long time to start up the controller again after boarding of the passenger on the vehicle. Consequently, the vehicle may not be launched promptly.

SUMMARY

Aspects of embodiments of the present disclosure have been conceived noting the foregoing technical problems, and it is therefore an object of the present disclosure is to provide a vehicle control system configured to allow an autonomous vehicle to promptly launch after picking up a passenger.

The vehicle control system according to the embodiments of the present disclosure is applied to a vehicle comprising a power source, a drive motor, a brake device that applies braking torque to a wheel, and a steering system that turns the wheels. The vehicle control system comprises a controller that controls the drive motor, the brake device and the steering system to operate the vehicle autonomously. The controller comprises a drive controller which controls the drive motor and to which electric power is supplied from the power source. The vehicle control system further comprises a main switch that is manipulated by the controller to selectively connect and disconnect the drive controller to/from the power source. The controller is configured to propel the vehicle autonomously to a pickup location to pick up a passenger, and to turn on the main switch if the passenger is detected within a predetermined area at the pickup location.

In a non-limiting embodiment, the vehicle control system may further comprise a relay switch that is manipulated by the controller to selectively connects and disconnects the drive motor to/from the power source. In addition, the controller may be further configured to turn off the relay switch if the passenger is detected within the predetermined area at the pickup location, and if an elapsed time from a time point at which the passenger was detected to a time point at which the passenger commands the vehicle to start autonomous propulsion is longer than a first predetermined period.

In a non-limiting embodiment, the vehicle control system may further comprise: a torque transmission route for delivering an output torque of the drive motor to drive wheels; and a parking lock mechanism that stops a rotation of a predetermined rotary member arranged in the torque transmission route irrespective of electric power supply from the power source, and that is manipulated by the controller to selectively allow and inhibit the rotary member to rotate. In addition, the controller may be further configured to stop the rotation of the rotary member by the parking lock mechanism if the elapsed time is longer than the first predetermined period.

In a non-limiting embodiment, the controller may be further configured to turn off the main switch if the passenger is not detected within the predetermined area at the pickup location, and if a waiting time from a time point at which the vehicle arrives at the pickup location to a time point at which the passenger appears within the predetermined area at the pickup location is longer than a second predetermined period.

In a non-limiting embodiment, the vehicle control system may further comprise a relay switch that that is manipulated by the controller to selectively connects and disconnects the drive motor to/from the power source. In addition, the controller may be further configured to turn off the relay switch if the waiting time is longer than the second predetermined period.

In a non-limiting embodiment, the vehicle control system may further comprise: a torque transmission route for delivering an output torque of the drive motor to drive wheels; and a parking lock mechanism that stops a rotation of a predetermined rotary member arranged in the torque transmission route irrespective of electric power supply from the power source, and that is manipulated by the controller to selectively allow and inhibit the rotary member to rotate. In addition, the controller may be further configured to stop the rotation of the rotary member by the parking lock mechanism if the waiting time is longer than the second predetermined period.

In a non-limiting embodiment, the controller may be further configured to turn off the main switch if the waiting time is longer than the second predetermined period, and to turn on the main switch again when the passenger approaches the predetermined area at the pickup location after turning off the main switch.

Thus, according to the embodiments of the present disclosure, the controller is configured to turn on the main switch thereby energizing the drive controller for controlling the drive motor if the passenger is detected within a predetermined area at the pickup location after arrival of the vehicle at the pickup location. That is, the drive controller has already been started when the passenger gets in the vehicle, or when the passenger commands the vehicle to start autonomous propulsion. According to the embodiments of the present disclosure, therefore, the vehicle is allowed to promptly start autonomous propulsion.

As described, the controller is further configured to turn off the relay switch to interrupt electric power supply to the drive motor if the passenger is detected within the predetermined area at the pickup location, and if the aforementioned elapsed time is longer than the first predetermined period. According to the embodiments of the present disclosure, therefore, standby power supplied to the drive motor may be saved.

As also described, the controller is further configured to stop the rotation of the rotary member by the parking lock mechanism when interrupting electric power supply to the drive motor. According to the embodiments of the present disclosure, therefore, a power loss resulting from actuating the brake device may be reduced.

As also described, the controller is further configured to temporality turn off the main switch if the waiting time to pick up the passenger at the pickup location is longer than the second predetermined period. According to the embodiments of the present disclosure, therefore, electric power consumption during waiting for the passenger may be reduced.

In addition, the controller is further configured to turn off the relay switch to interrupt electric power supply to the drive motor if the waiting time to pick up the passenger at the pickup location is longer than the second predetermined period. According to the embodiments of the present disclosure, therefore, standby power supplied to the drive motor may be saved.

In this case, the controller also stops the rotation of the rotary member by the parking lock mechanism. According to the embodiments of the present disclosure, therefore, a power loss resulting from actuating the brake device may also be reduced.

In this case, when the passenger appears at the pickup point after turning off the main switch, the controller turns on the main switch again to startup the drive controller. According to the embodiments of the present disclosure, therefore, the vehicle is allowed to promptly start autonomous propulsion when the passenger gets in the vehicle, or when the passenger commands the vehicle to start autonomous propulsion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Embodiments of the present disclosure will now be explained with reference to the accompanying drawings. The control system according to the embodiments of the present disclosure may be applied to a hybrid vehicle powered by an engine and a motor(s), and an electric vehicle powered by the motor(s). In the vehicles of these kinds, electric power may be supplied to the motor not only from a battery but also from a fuel cell.

Referring now toFIG. 1, there is schematically shown a structure of a hybrid vehicle (as will be simply called the “vehicle” hereinafter) Ve to which the control system according to the embodiments of the present disclosure is applied. In the vehicle Ve, a prime mover includes an engine1, a first motor2and a second motor3. A damper device5is disposed on an output shaft4of the engine1to absorb vibrations resulting from torque pulse. The damper device5comprises an input member6connected to the output shaft4of the engine1, an output member7that is allowed to rotate relatively to the input member6, and a plurality of elastic members8arranged in a circular manner at regular intervals to transmit torque of the input member6to the output member7.

One end of an input shaft9is connected to the output member7to be rotated integrally therewith, and other end of the input shaft9is connected to a single-pinion planetary gear unit10. The planetary gear unit10comprises a sun gear11fitted onto the input shaft9, a ring gear12arranged concentrically with the sun gear11, a plurality of pinion gears13interposed between the sun gear11and the ring gear12, and a carrier14supporting the pinion gears13while allowing to revolve around the sun gear11.

A first cylindrical shaft15extends from the sun gear11on the input shaft9toward the engine1to be connected to the first motor2. For example, a permanent magnet type synchronous motor having a generating function may be used as the first motor2. In the first motor2, a rotor2ais connected to the first cylindrical shaft15of the sun gear11to be rotated integrally therewith, and a stator2bis fixed to a stationary member16such as a housing.

A second cylindrical shaft17extends from the ring gear12toward the second motor3, and a rotor3aof the second motor3is connected to the second cylindrical shaft17to be rotated integrally therewith. A stator3bof the second motor3is fixed to the stationary member16such as a housing.

A leading end of the second cylindrical shaft17is connected to an output shaft18as a rotary member to be rotated integrally therewith, and a parking gear19as an external gear is fitted onto the output shaft18to be rotated integrally therewith. A parking lock mechanism20is arranged outside of the parking gear19. The parking lock mechanism20comprises a parking pawl21and a parking actuator22. The parking actuator22may be actuated not only manually by a passenger but also automatically by an electronic control unit (as will be called the “controller” hereinafter)23to bring the parking pawl21into engagement with the parking gear19thereby locking the output shaft18. An engagement between the parking pawl21and the parking gear19may be maintained even after shutting down a battery as a power source24.

A leading end of the output shaft18is connected to a differential gear unit25, and the differential gear unit25is connected to a pair of drive wheels27through drive shafts26extending laterally. The drive wheels27are turned by a steering system28. Rotations of the drive wheels27and another pair of wheels29are individually stopped by a brake device30.

An operating mode of the vehicle Ve may be selected from a hybrid mode (to be abbreviated as the “HV mode” hereinafter) in which the vehicle Ve is powered at least by the engine1, and an electric vehicle mode (to be abbreviated as the “EV mode” hereinafter) in which the vehicle Ve is powered by at least one of the first motor2and the second motor3. Specifically, in the HV mode, the engine1generates power in accordance with a required drive force calculated by the controller23, and the first motor2generates reaction torque in such a manner as to deliver the output power of the engine1to the drive wheels27through the planetary gear unit10. In this situation, electric power generated by the first motor2may be supplied to the second motor3so that an output torque of the second motor may be applied to the second cylindrical shaft17. That is, the output power of the engine1may be translated partially into the electric power by the first motor2, and then translated into kinetic energy again by the second motor3to be applied to a torque transmission route R between the engine1and the drive wheels27. By contrast, when the first motor2serves as a motor while establishing the reaction torque, output torque of the first motor2applied to the transmission route R may be translated into electric power by the second motor3, thereby reducing power transmitted through the transmission route R.

In the EV mode, the second motor3is operated as a motor in such a manner as to achieve a required drive force calculated by the controller23. In this situation, fuel supply to the engine1and power supply to the first motor2may be interrupted.

As shown inFIG. 1, the first motor2is connected to a first inverter31, and the second motor3is connected to a second inverter32. The first inverter31and the second inverter32are also connected to an output terminal of the battery24through a positive bus line33and a negative bus line34. The first motor2and the second motor3are also connected to each other through the positive bus line33and the negative bus line34so that electric power generated by one of the motors2and3is supplied to the other motor2or3. A capacitor35for storing electric power is connected parallel to the positive bus line33and the negative bus line34, and an auxiliary36e.g., a compressor for activating an air conditioner is also connected to the positive bus line33and the negative bus line34. In order to selectively allow and interrupt power supply from the battery24to the first inverter31and the second inverter32, a relay switch37is individually disposed on the positive bus line33and the negative bus line34between the output terminal of the battery24and the first inverter31and the second inverter32. The relay switch37may be turned on and turned off manually by manipulating a switch button or key, but also automatically at desired time by setting a timer or the controller23.

A configuration of the controller23is shown inFIG. 2. The controller23comprises a main controller38, a drive controller39and a sub-controller40. Output signals from the main controller38are sent to the drive controller39and the sub-controller40. Incident signals to the drive controller39are converted into drive commands and further transmitted to a throttle actuator of the engine1, the first motor2, and the second motor3. Incident signals to the sub-controller40is converted into appropriate command signals and further transmitted to actuators59of the brake30etc.

In order to selectively connect and disconnect the drive controller39to/from the battery24depending on an operating condition of the switch button or key for energizing the relay switch37, a main switch41is arranged between the battery24and the drive controller39. For example, when the switch button is pressed, the main switch41is turned on, and then, if the switch button is pressed for a predetermined period of time, the relay switch37is turned on. The main switch41is controlled by the main controller38to automatically allow and interrupt electric power supply to the drive controller39.

The main controller38is an electronic control unit composed mainly of a microcomputer. To the main controller38, detection signals and information about operating conditions and behaviors of constituent elements of the vehicle Ve are transmitted from an internal sensor42. Specifically, the internal sensor42includes an accelerator sensor44for detecting a position of an accelerator pedal43, a brake sensor (or switch)46for detecting a depression of a brake pedal45, a steering sensor48for detecting a steering angle of the steering wheel47, a vehicle speed sensor49for detecting rotational speeds of the wheels27and29, a longitudinal acceleration sensor50for detecting a longitudinal acceleration of the vehicle Ve, a lateral acceleration sensor51for detecting a lateral acceleration of the vehicle Ve, a yaw rate sensor52for detecting a yaw rate of the vehicle, a shift sensor54for detecting a position of a shift lever (or switch)53and so on. The main controller38transmits command signals for controlling the engine1, the first motor2and the second motor3to the drive controller39, and transmits command signals for controlling the brake30and so on to the sub-controller40based on incident signals from the internal sensor42as well as maps and formulas installed in advance. InFIG. 1, dashed-lines represent transmission of signals between the internal sensor42and the controller23, and between the controller23to the engine1, the first motor2, the second motor3and the brake30.

As described, the vehicle Ve is operated autonomously while manipulating the engine1, the first motor2, the second motor3, the brake30and so on by the controller23. In addition, the steering system28, the parking lock mechanism20and so on are also controlled by the controller23.

In order to operate the vehicle Ve autonomously, detection signals from external sensors55for detecting external conditions are also sent to the main controller38. For example, the external sensor55includes at least one of an on-board camera, a RADAR (i.e., a radio detection and ranging) a LIDAR (i.e., a laser imaging detection and ranging), an ultrasonic sensor and so on.

Specifically, the on-board camera is arranged inside of a windshield glass, and transmits recorded information about the external condition to the main controller38. To this end, not only a monocular camera but also a stereo camera having a plurality of lenses and image sensors to achieve a binocular vision may be used as the on-board camera. If the stereo camera is used as the on-board camera, the main controller38is allowed to obtain three-dimensional information in the forward direction.

The RADAR is adapted to detect obstacles utilizing radio waves such as millimetric-waves and microwaves, and to transmit detected information to the main controller38. Specifically, the RADAR detects an obstacle such as other vehicles and so on by emitting radio waves and analyzing the radio waves reflected from the obstacle.

Likewise, the LIDAR is adapted to detect obstacles utilizing laser light and to transmit detected information to the main controller38. Specifically, the LIDAR detects an obstacle such as other vehicles and so on by emitting laser light and analyzing the laser light reflected from the obstacle.

In addition, the vehicle Ve is further provided with a GPS (i.e., global positioning system) receiver56, a digital map database57, and a navigation system58. Specifically, the GPS receiver56is adapted to obtain a position (i.e., latitude and longitude) based on incident signals from GPS satellites, and to transmit the positional information to the main controller38. The map database57may be installed in the main controller38, but map information stored in external online information processing systems may also be available. The navigation system58is configured to determine a travelling route of the vehicle Ve based on the positional information obtained by the GPS receiver56and the map database57.

The main controller38carries out calculations based on the incident data or information from the internal sensor42and the external sensor55as well as the preinstalled data, and calculation results are sent in the form of command signal to the drive controller39and the sub-controller40. The incident signals to the drive controller39are converted into drive commands, and further transmitted to the throttle actuator of the engine1, and the first inverter31and the second inverter32of the first motor2and the second motor3. The incident signals to the sub-controller40is converted into appropriate command signals and further transmitted to the actuators59of the brake30, the steering system28and so on.

The actuator59includes a brake actuator, a steering actuator and so on. Specifically, the brake actuator is adapted to actuate the brake30to control braking force applied to the wheels27and29in response to reception of the command signal from the sub-controller40. The steering actuator is adapted to activate an assist motor of the steering system28to control a steering torque in response to reception of the command signal from the sub-controller40.

The main controller38comprises a position recognizer60, an external condition recognizer61, a running condition recognizer62, a travel plan creator63, a travel controller64and so on.

Specifically, the position recognizer60is configured to recognize a current position of the vehicle Ve on the map based on the positional information received by the GPS receiver56and the map database57. The current position of the vehicle Ve may also be obtained from the positional information used in the navigation system58. Optionally, the vehicle Ve may also be adapted to communicate with external sensors arranged along the road to obtain the current position of the vehicle Ve.

The external condition recognizer61is configured to recognize external condition of the vehicle Ve such as a location of a traffic lane, a road width, a road configuration, a road gradient, an existence of obstacles around the vehicle Ve and so on, based on the recorded information of the on-board camera, or detection data of the RADAR or the LIDAR. Optionally, weather information, a friction coefficient of road surface etc. may be obtained according to need.

The running condition recognizer62is configured to recognize running condition of the vehicle Ve such as a vehicle speed, a longitudinal acceleration, a lateral acceleration, a yaw rate and so on based on detection result of the internal sensors42.

The travel plan creator63is configured to create a travel locus of the vehicle Ve based on a target course determined by the navigation system58, a position of the vehicle Ve recognized by the position recognizer60, and an external condition recognized by the external condition recognizer61. That is, the travel plan creator63creates a travel locus of the vehicle Ve within the target course in such a manner that the vehicle Ve is allowed to travel safely and properly while complying traffic rules.

In addition, the travel plan creator63is further configured to create a travel plan in line with the created travel locus. Specifically, the travel plan creator63creates a travel plan in line with the target course based on the external conditions recognized by the external condition recognizer61and the map database57.

Specifically, the travel plan is created based on prospective data after few seconds from the present moment to determine a future condition of the vehicle Ve such as a driving force or the like required in future. Optionally, the travel plan may also be created based on prospective data after several ten seconds depending on the external conditions and the running conditions. Thus, the travel plan creator63creates a future plan to change a vehicle speed, acceleration, steering torque etc. during travelling along the target course in the form of e.g., a map.

Alternatively, the travel plan creator63may also create a pattern to change the vehicle speed, acceleration, steering torque etc. between predetermined points on the travel locus. Specifically, such patterns may be determined by setting target values of those parameters at each point on the travel locus taking account of a required time to reach the point at the current speed.

The travel controller64is configured to operate the vehicle Ve autonomously in line with the travel plan created by the travel plan creator63. To this end, specifically, the travel controller64transmits command signals to the actuators59, or the engine1, the first motor2and the second motor3through the drive controller39and the sub-controller40.

The vehicle Ve may be operated autonomously without a driver to pick up a passenger at a desired pickup location by entering a desired pickup time and location into the main controller38. To this end, the main controller38automatically turns on the main switch41at a time calculated based on the desired pickup time and location. However, the vehicle Ve may arrive at the pickup location earlier than an estimated time of arrival depending on traffic on the planed route. In this case, if the vehicle Ve has to wait the passenger for a long time while turning on the main switch41, activation of the drive controller39is maintained while consuming electric power. In order to prevent such waste of electric power, it is preferable to turn off the main switch41. However, once the main switch41is turned off, the drive controller39has to be started up by turning on the main switch41after picking up the passenger, and such procedure takes time. Consequently, the vehicle Ve may not be allowed to launch promptly.

In order to avoid the above-explained disadvantages, the control system according to the embodiments of the present disclosure executes a routine shown inFIG. 3to launch the vehicle Ve promptly after picking up the passenger at the pickup location, and to save electricity while waiting the passenger at the pickup location.

The routine shown inFIG. 3is started when the vehicle Ve is launched autonomously to the pickup location to pick up a passenger. First of all, it is determined at step S1whether or not the vehicle Ve has arrived at the pickup location. Such determination at step S1may be made with reference to a destination entered into the main controller38and positional information obtained by the position recognizer60.

If the vehicle Ve has not yet arrived at the pickup location so that the answer of step S1is NO, the routine progresses to step S2to continue autonomous propulsion to the pickup location, and then returns. By contrast, if the vehicle Ve arrives at the pickup location so that the answer of step S1is YES, the routine progresses to step S3to maintain the braking forces being applied to the wheels27and29. Then, the routine progresses to step S4to determine a presence of the passenger within a predetermined area around the vehicle Ve. In other words, at step S4, it is determined whether or not a startup of the drive controller39can be completed before the passenger gets in the vehicle Ve, or before the vehicle Ve launches after picking up the passenger. To this end, the predetermined area may be set based on a required period of time to complete a startup of the drive controller39, and a required period of time for the passenger to get in the vehicle Ve at the pickup location, or a required period of time to command the vehicle Ve to propel autonomously after the vehicle Ve arrived at the pickup location. For example, a presence of the passenger within the predetermined area around the vehicle Ve may be determined based on a fact that: a wireless signal from the key of the vehicle Ve is received by the vehicle Ve; or a door is opened and closed by the passenger. Optionally, at step S4, occupancy of the vehicle seat may be determined for each seat. To this end, a pressure sensor may be arranged in each seat to send a signal e.g., to the main controller38.

If the control system detects a passenger within the predetermined area around the vehicle Ve so that the answer of step S4is YES, the routine progresses to step S5to keep the main switch41turned on.

At the pickup location, the passenger may not always get in the vehicle Ve promptly. In addition, although the passenger gets in the vehicle Ve, the passenger may not always command the vehicle Ve to launch immediately to the next destination. In those cases, if the relay switch37is continuously turned on, electric power is continuously consumed to supply standby power to the first motor2and the second motor3as long as the vehicle Ve is stopped. By contrast, if the relay switch37is turned off, the vehicle Ve is launched after turning on the relay switch37. Consequently, commencement of propulsion of the vehicle Ve lags behind a transmission of a command signal to launch the vehicle Ve autonomously. In order to avoid such disadvantages, the control system compares an elapsed time t1from a time point at which the passenger was detected at step S4to a time point at which the passenger commands the vehicle Ve to start autonomous propulsion, to a first predetermined period α that is fundamentally required for the passenger to command the vehicle Ve to start autonomous propulsion from a time point at which the vehicle Ve picks up the passenger. If the elapsed time t1is shorter than the first predetermined period α, the relay switch37is maintained to be turned on. By contrast, if the elapsed time t1is longer than the first predetermined period α, the relay switch37is turned off. In this case, in order to save time to start the drive controller39before launching the vehicle Ve, activation of the drive controller39is maintained.

Specifically, after maintaining the main switch41to be turned on at step S5, the routine progresses to step S6to determine whether or not the elapsed time t1is equal to or shorter than the first predetermined period α. If the elapsed time t1is equal to or shorter than the first predetermined period α so that the answer of step S6is YES, the routine progresses to step S7to maintain an operating range to a drive range. In this case, specifically, the main switch41and the relay switch37are continuously turned on, and the braking forces of the brakes30applied to the wheels27and29are maintained. By contrast, if the elapsed time t1exceeds the first predetermined period α so that the answer of step S6is NO, the routine progresses to step S8to shift the operating range to a parking range. In this case, the relay switch37is turned off while keeping the main switch41to be turned on, and the parking lock mechanism20is actuated to engage the parking pawl21with the parking gear19thereby locking the output shaft18. In other words, the vehicle Ve is brought into a neutral state in which a torque transmission between the engine1and the drive wheels27is interrupted while stopping a rotation of the output shaft18. In this case, after engaging the parking pawl21with the parking gear19, the braking forces of the brakes30applied to the wheels27and29may be reduced.

After thus selecting the operating range at step S7or S8, the routine progresses to step S9to determine whether or not the vehicle Ve is commanded to propel autonomously to the next destination. For example, such determination at step S9may be made based on a fact that the next destination is entered into the navigation system58. If the vehicle Ve is commanded to propel autonomously so that the answer of step S9is YES, the routine progresses to step S10to launch the vehicle Ve autonomously. In this situation, if the operating range is in the drive range, the vehicle Ve is launched autonomously while reducing the braking forces of the brakes30. By contrast, if the operating range is in the parking range, the vehicle Ve is launched autonomously by shifting the operating range to the drive range, while disengaging the parking pawl21from the parking gear19and turning on the relay switch37.

By contrast, if the vehicle Ve is not commanded to propel autonomously so that the answer of step S9is NO, the routine returns to step S6to repeat the determination of step S6. In this case, steps S7and S9are repeated until the elapsed time t1exceeds the first predetermined period α. Then, steps S6, S8and S9are repeated until the vehicle Ve is commanded to propel autonomously.

If the passenger is not present within the predetermined area around the vehicle Ve at the pickup location, the vehicle Ve will not start autonomous propulsion from the pickup location and hence it is preferable to interrupt electric power supply to the drive controller39so as to save the electric power. By contrast, if the passenger appears at the pickup location before the arrival of the vehicle Ve at the pickup location, the vehicle Ve may be launched immediately when picking up the passenger. In this case, it is preferable to maintain the activation of the drive controller39to allow the vehicle Ve to launch promptly. In order to fulfill such requirements, the control system compares a waiting time t2from a time point at which the vehicle Ve arrives at the pickup location to a time point at which the passenger appears within the predetermined area at the pickup location, to a second predetermined period β that is fundamentally required for the passenger picked up by the vehicle Ve to command the vehicle Ve to start autonomous propulsion from a time point at which the vehicle Ve arrives at the pickup location. That is, the second predetermined period β is longer than the first predetermined period α. If the waiting time t2is longer than the second predetermined period β, electric power supply to the drive controller39is interrupted. By contrast, if the waiting time t2is shorter than the second predetermined period β, the electric power is continuously supplied to the drive controller39.

Specifically, if the control system does not detect a passenger within the predetermined area around the vehicle Ve so that the answer of step S4is NO, the routine progresses to step S11to determine whether or not the waiting time t2is equal to or longer than the second predetermined period β. If the waiting time t2is shorter than the second predetermined period β so that the answer of step S11is NO, the routine progresses to step S5to keep the main switch41turned on. Then, the routine progresses to step S13to maintain the braking forces of the brakes30being applied to the wheels27and29, and returns to step S11. By contrast, if the waiting time t2exceeds the second predetermined period β so that the answer of step S11is YES, the routine progresses to step S14to shift the operating range to the parking range. Then, the routine progresses to step S15to reduce the braking force of the brakes30being applied to the wheels27and29, and further progresses to step S16to turn off the main switch41.

In the case that the waiting time t2is longer than the second predetermined period β, the vehicle Ve may not be launched promptly after picking up the passenger if the main switch41is turned off. In order to avoid such disadvantage, after turning off the main switch41at step S16, the routine progresses to step S17to determine whether or not the passenger approaches the predetermined area around the vehicle Ve. Such determination at step S17may be made based on the same factors as those used at step S4. If the passenger does not approach the predetermined area around the vehicle Ve so that the answer of step S17is NO, the determination at step S17is repeated. By contrast, if the passenger approaches the predetermined area around the vehicle Ve so that the answer of step S17is YES, the routine progresses to step S18to turn on the main switch41. Then, the routine progresses to step S6to execute steps S6to S10by the above-explained procedures. Alternatively, at step S17, it is also possible to determine boarding of the passenger on the vehicle Ve based on the signal from the pressure sensor arranged in the vehicle seat.

Thus, in the case that the passenger is detected within the predetermined area around the vehicle Ve, the main switch41is turned on to activate the drive controller39. That is, the drive controller39has already been started when the passenger gets in the vehicle Ve, or when the passenger commands the vehicle Ve to start autonomous propulsion. In this case, therefore, the vehicle Ve is allowed to promptly start autonomous propulsion. In this situation, the engine1may be operated while the vehicle Ve is stopped to charge the battery24by operating the first motor2as a generator. In addition, an oil pump and so on may be driven by the engine1.

If the elapsed time t1is longer than the first predetermined period α, that is, if the vehicle Ve is waiting for the passenger for a long time since detecting the passenger, the relay switch37is turned off while maintaining the main switch41turned on. That is, electric power supply to the first motor2and the second motor3is stopped while maintaining activation of the drive controller39. In this situation, therefore, the vehicle Ve can be launched promptly upon receipt of a command to propel the vehicle Ve autonomously, and electricity consumption can be reduced until the vehicle Ve is commanded to start autonomous propulsion. As described, in the vehicle Ve, output power of the engine1is delivered to the drive wheels27by establishing reaction torque by the first motor2. In the vehicle Ve, therefore, the transmission route R is brought into the neutral state by stopping electric power supply to the first motor2and the second motor3. In this situation, output torque of the engine1will not be delivered to the drive wheels27and hence the vehicle Ve can be prevented from being propelled unintentionally.

In addition, in the case that the elapsed time t1is longer than the first predetermined period α, a power loss resulting from actuating the brake30may be reduced by locking the parking gear19by the parking lock mechanism20.

In the case that the waiting time t2is longer than the second predetermined period β, the main switch41is temporality turned off so that electric power supply to the drive controller39is interrupted to save to save the electric power.

In this case, the standby power supplied to the first motor2and the second motor3can be saved by turning off the relay switch37.

In this case, a power loss resulting from actuating the brake30may also be reduced by locking the parking gear19by the parking lock mechanism20. In addition, after thus locking the parking gear19by the parking lock mechanism20, torsion in the transmission route between the output shaft18and the drive wheels27may be eliminated before the boarding of the passenger by reducing the braking forces of the brake devices30. Consequently, the passenger will not sense shocks resulting from eliminating the torsion in the transmission route.

In this case, when the passenger appears at the pickup point after turning off the main switch41, the main switch41is turned on again to startup the drive controller39. For this reason, the vehicle Ve is allowed to promptly start autonomous propulsion when the passenger gets in the vehicle Ve, or when the passenger commands the vehicle Ve to start autonomous propulsion.

Although the above exemplary embodiments of the present application have been described, it will be understood by those skilled in the art that the present application should not be limited to the described exemplary embodiments, and various changes and modifications can be made within the spirit and scope of the present application. For example, electric power supply from the battery24to the RADAR and the LIDAR may also be interrupted by another relay switch. In this case, electric power supply to the RADAR and the LIDAR is stopped if the elapsed time t1is longer than the first predetermined period α, or if the waiting time t2is longer than the second predetermined period β to save electricity. The RADAR and the LIDAR may be activated when the vehicle Ve is commanded to propel autonomously or when the passenger approaches the predetermined area around the vehicle Ve to launch the vehicle Ve promptly.