JP6491505B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device for a vehicle driven by a motor and an engine.

  In recent years, a vehicle equipped with so-called hill descent control that reduces the load on the driver by keeping the vehicle speed at a constant speed even when the vehicle is traveling on a downhill without the operation of an accelerator or a brake has become widespread. For example, Patent Documents 1 and 2 disclose techniques relating to hill descent control.

JP 61-102336 A Special table 2013-537145 gazette

  By the way, depending on the driving conditions, such as when the vehicle speed is higher than the target vehicle speed during constant-speed driving processing that maintains the vehicle speed at the target vehicle speed as in the above-mentioned Hill Descent Control, even if the engine is reduced to the minimum output, the brakes Braking may be required. In this case, the fuel is wasted in the engine and the brake is also consumed.

  Accordingly, an object of the present invention is to provide a vehicle control device capable of suppressing brake consumption while suppressing fuel consumption during constant speed traveling processing.

In order to solve the above problems, a vehicle control device for a vehicle driven by a motor and an engine according to the present invention includes a control unit, and the control unit satisfies a predetermined condition including that the vehicle speed is equal to or lower than a predetermined speed . vehicle speed to perform the constant speed running process for controlling the motor and the engine to a predetermined target vehicle speed, in response to detecting that it performs a constant-speed running processing, the imaging from the imaging unit for imaging the front of the vehicle the relative inclination angle is a relative angle of inclination with respect to the vehicle traveling road in front of the vehicle is derived on the basis of the image, is derived based on the vehicle speed and the target vehicle speed, the target torque Ru advancing the vehicle, engine If less than the creep torque minimum output in order to maintain the driving state of, when performing a control process for stopping the engine, that is performing constant-speed running processing is not detected, Characterized in that it does not carry out the control process.

The control unit may further acquire vehicle tilt information and derive a target torque based on the tilt information in addition to the relative tilt angle , the vehicle speed, and the target vehicle speed.

The relative inclination angle may be an average value of an inclination angle relative to the vehicle on the traveling road, which is derived over a predetermined range of the traveling road based on the image .

  According to the present invention, it is possible to suppress brake consumption while suppressing fuel consumption during constant speed running processing.

It is a figure which shows the structure of the control system of a hybrid vehicle. It is a flowchart which shows the flow of a vehicle control process.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating a configuration of a control system of hybrid vehicle 100. Here, the configuration related to the feature of the present embodiment will be described in detail, and the description of the configuration unrelated to the feature of the present embodiment will be omitted.

  As shown in FIG. 1, the hybrid vehicle 100 includes an engine 102 and a motor 104 as drive sources.

  The hybrid vehicle 100 includes vehicle control devices, that is, HEVCU (Hybrid and Electric Vehicles Control Units) 200, ECU (Engine Control Unit) 202, MCU (Motor Control Unit) 204, BCU (Brake Control Unit) 206, GCU (GCU). It is controlled by Graphical Control Unit) 208.

  The HEVCU 200 is a microcomputer including a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory), and comprehensively controls each part of the hybrid vehicle 100.

  The HEVCU 200 is electrically connected to an accelerator sensor 106, a brake sensor 108, a shift position sensor 110, a G sensor 112, and a vehicle speed sensor 114. The accelerator sensor 106 detects an accelerator pedal depression amount (accelerator depression amount) and outputs a signal indicating the accelerator depression amount to the HEVCU 200 and the BCU 206. The brake sensor 108 detects the depression amount (brake depression amount) of the brake pedal, and outputs a signal indicating the brake depression amount to the HEVCU 200 and the BCU 206. The shift position sensor 110 detects the shift position (neutral, drive, back, etc.) of the shift lever, and outputs a signal indicating the shift position to the HEVCU 200.

  G sensor 112 detects an inclination direction and an inclination angle in which the height direction of the vehicle body of hybrid vehicle 100 is inclined with respect to the direction of gravity, and outputs a signal indicating the inclination direction and the inclination angle to HEVCU 200. Here, the inclination direction and the inclination angle are inclination information indicating the inclination of the hybrid vehicle 100. For example, the vehicle speed sensor 114 detects the number of rotations of the axle and converts it into a vehicle speed, and outputs a signal indicating the vehicle speed to the HEVCU 200 and the BCU 206.

  The HEVCU 200 calculates the target engine torque and the target motor torque to be output from the engine 102 and the motor 104 based on a target torque map stored in advance in the ROM based on the accelerator depression amount transmitted from the accelerator sensor 106 and the vehicle speed. Set.

  The ECU 202 is a microcomputer including a CPU, RAM, and ROM, and controls the engine 102. The ECU 202 is electrically connected to the fuel injection device 102a, the throttle device 102b, and the ignition device 102c of the engine 102. The ECU 202 controls the fuel injection device 102a, the throttle device 102b, and the ignition device 102c at predetermined timings based on the control of the HEVCU 200.

  The ECU 202 is electrically connected to an engine speed sensor 102d that measures the speed of the engine 102 and an airflow sensor 102e provided in the intake air introduction path. The ECU 202 adjusts the throttle opening amount of the throttle device 102b according to the engine speed measured by the engine speed sensor 102d and the target engine torque from the HEVCU 200. Further, the ECU 202 calculates the actual engine torque of the engine 102 by adapting the actual charging efficiency calculated based on the throttle passage flow rate measured by the air flow sensor 102e to the torque map stored in advance. A signal indicating torque is output to HEVCU 200.

  The MCU 204 is a microcomputer including a CPU, RAM, and ROM, and controls the motor 104. The MCU 204 is electrically connected to the motor 104 and the motor rotation speed sensor 116. The MCU 204 controls the drive of the motor 104 based on the target motor torque from the HEVCU 200. Further, the MCU 204 calculates the actual motor torque of the motor 104 by applying the rotational speed of the motor 104 measured by the motor rotational speed sensor 116 to a torque map stored in advance, and sends information indicating the actual motor torque to the HEVCU 200. Output.

  The BCU 206 is a microcomputer including a CPU, a RAM, and a ROM, and controls the brake device 118. The BCU 206 is electrically connected to a brake device 118 such as a disc brake or a drum brake, an accelerator sensor 106, a brake sensor 108, and a vehicle speed sensor 114. The BCU 206 controls the brake device 118 according to the output signal from each connected sensor, and performs antilock brake control, traction control, vehicle dynamics control, and the like.

  The GCU 208 is a microcomputer including a CPU, a RAM, and a ROM, and recognizes a driving environment outside the vehicle based on color information and position information in images captured by the two imaging devices 120 and 122 (imaging unit). The two imaging devices 120 and 122 are configured to include an imaging element such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The imaging devices 120 and 122 capture the front of the hybrid vehicle 100 and generate a monochrome image or a color image. The imaging devices 120 and 122 are in two pairs, and are spaced apart in a substantially horizontal direction so that their optical axes are substantially parallel on the traveling direction side of the hybrid vehicle 100.

  The GCU 208 obtains image data from each of the two imaging devices 120 and 122, and a block corresponding to a block arbitrarily extracted from one of the two images (for example, an array of horizontal 4 pixels × vertical 4 pixels) from the other image. The parallax is derived using so-called pattern matching to search. Here, “horizontal” indicates the horizontal direction of the captured image, and “vertical” indicates the vertical direction of the captured image. The GCU 208 performs such a block-unit parallax derivation process for all blocks displayed in the detection area (for example, horizontal 600 pixels × vertical 180 pixels). Here, the block is assumed to be horizontal 4 pixels × vertical 4 pixels, but the number of pixels in the block can be arbitrarily set.

  Subsequently, the GCU 208 derives three-dimensional position information including a horizontal distance, a height, and a relative distance using a so-called stereo method based on the parallax for each block in the detection region. Here, the stereo method is a method of deriving a relative distance of the block with respect to the imaging devices 120 and 122 from the parallax of the block by using a triangulation method. At this time, the GCU 208 derives the height of the block from the road surface based on the relative distance of the block and the distance on the detection area from the point on the road surface at the same relative distance to the block to the block.

  Next, the GCU 208 uses an arbitrary block as a base point, and the block and a block whose horizontal distance difference, height difference, and relative distance difference are within a predetermined range (for example, 0.1 m), Grouping is performed assuming that the objects correspond to the same three-dimensional object. In this way, a three-dimensional object that is a virtual block group is generated. The above range is represented by a distance in real space, and can be set to an arbitrary value by a manufacturer or a passenger. The GCU 208 further groups blocks that have a horizontal distance difference, a height difference, and a relative distance difference within a predetermined range with respect to a block that is newly added by grouping. As a result, all blocks that can be assumed to be the same specific object are grouped.

  Subsequently, the GCU 208, for example, if the grouped three-dimensional object satisfies a predetermined condition corresponding to a predetermined vehicle (for example, the three-dimensional object is located on the road and the size of the entire three-dimensional object is If it corresponds to the size of the specific object “vehicle”), the three-dimensional object is specified as the specific object “vehicle”. Then, the GCU 208 specifies a vehicle having the same traveling direction as that of the host vehicle based on the positional relationship with the host vehicle and the relative speed among the specific item “vehicle” and sets it as a preceding vehicle.

  In addition, the GCU 208 specifies a white line attached on the road, and specifies the relative height of the traveling road (road) ahead with respect to the position of the hybrid vehicle 100 from the three-dimensional position of the white line.

  Here, the traveling environment includes the state of the road in front of the hybrid vehicle 100 accompanying the traveling of the hybrid vehicle 100, the state of the building located outside the road, the traveling state of the vehicle that travels or crosses the road, and walking. Comprehensive environmental information including the movement status of persons etc. The hybrid vehicle 100 follows the preceding vehicle while avoiding a collision with an obstacle or keeping a relative distance (inter-vehicle distance) with the preceding vehicle at a predetermined distance based on such a traveling environment. The following cruise control and so-called constant speed cruise control that travels while maintaining the vehicle speed at a predetermined target speed are realized.

  Since the specific processing by the GCU 208 described above can adopt various existing technologies such as Japanese Patent No. 5580233, detailed description thereof is omitted here.

  The hybrid vehicle 100 uses a motor travel mode in which the motor 104 travels in preference to the engine 102 when the remaining battery capacity is sufficient, and the motor 104 and the engine 102 are used together when the remaining battery capacity is small. A plurality of traveling modes are prepared, such as an engine combined mode for traveling, specifically a constant speed traveling mode that permits execution of a constant speed traveling process described later. Such a travel mode can be selected by, for example, a driver's operation input.

For example, in the hybrid vehicle 100, when the traveling mode is selected according to the remaining battery capacity and the engine combined mode is selected, the driving state of the engine 102 and the motor 104 is switched according to the traveling state, and the energy It is possible to increase efficiency and reduce exhaust gas such as CO ₂ .

  Further, the hybrid vehicle 100 can perform a constant speed traveling process for controlling the engine 102 and the motor 104 so that the vehicle speed becomes a predetermined target vehicle speed while traveling at a low speed on a downhill, for example. At this time, the BCU 206 functions as the vehicle speed control unit 210. The HEVCU 200 functions as an inclination information acquisition unit 212, a relative inclination angle derivation unit 214, a torque derivation unit 216, and a stop control unit 218.

  The vehicle speed control unit 210 performs the above-described constant speed traveling process when a predetermined condition is satisfied. Here, the predetermined condition includes, for example, satisfying all the following items. That is, the accelerator depression amount and the brake depression amount are 0, the vehicle speed of the hybrid vehicle 100 specified based on the output signal from the vehicle speed sensor 114 is equal to or lower than a predetermined speed (for example, 20 km / m), a constant speed This is a constant speed travel permission mode that permits execution of travel processing. Such a constant speed travel permission mode can be selected by, for example, a driver's operation input.

  Further, when the constant speed traveling process is started, the vehicle speed control unit 210 sets the vehicle speed at the start of the constant speed traveling process as the target vehicle speed. For example, when the target vehicle speed is low, the driver depresses the accelerator pedal once to accelerate, interrupts the constant speed traveling process, and then releases the accelerator pedal to restart the constant speed traveling process. The target vehicle speed can be changed.

  The vehicle speed control unit 210 turns on a constant speed running flag indicating that the constant speed running process is being performed when starting the constant speed running process, and ends the constant speed running process when the constant speed running process ends. Turn off.

  If the vehicle speed exceeds the target vehicle speed during the constant speed running process, the vehicle speed control unit 210 controls the brake device 118 to decelerate so that the vehicle speed becomes the target vehicle speed. When the vehicle speed is less than the target vehicle speed, the vehicle speed control unit 210 outputs a signal instructing the HEVCU 200 to accelerate. The HEVCU 200 sets a target engine torque and a target motor torque that the engine 102 and the motor 104 should output based on a vehicle speed that is insufficient relative to the target vehicle speed, for example, based on a target torque map.

  The inclination information acquisition unit 212 acquires a signal (inclination information) from the G sensor 112.

  The relative inclination angle deriving unit 214 acquires information indicating the relative height of the traveling road (road) ahead of the position of the hybrid vehicle 100 from the GCU 208, and from the continuous change in the height of the traveling road, A relative inclination angle (hereinafter referred to as a relative inclination angle) with respect to the hybrid vehicle 100 in the forward travel path is derived. That is, the relative inclination angle deriving unit 214 cooperates with the GCU 208 to derive the relative inclination angle based on the images captured by the imaging devices 120 and 122.

  The torque deriving unit 216 derives a target torque for moving the hybrid vehicle 100 forward based on the vehicle speed, the target vehicle speed, the inclination information, and the relative inclination angle. Specifically, the torque deriving unit 216 acquires information indicating the target vehicle speed from the BCU 206. Further, the torque deriving unit 216 matches the inclination of the hybrid vehicle 100 indicated by the inclination information with the relative inclination angle of the front traveling road derived by the relative inclination angle deriving unit 214, so that the actual traveling road is actually measured. The inclination (inclination with respect to the horizontal plane direction perpendicular to the direction of gravity) is derived.

  Then, the torque deriving unit 216 determines, based on the inclination of the front travel path, the amount of gravity acting on the hybrid vehicle 100 when the hybrid vehicle 100 travels on the front travel path in parallel to the traveling direction of the hybrid vehicle 100. Deriving force. The torque deriving unit 216 derives a difference value between the vehicle speed and the target vehicle speed.

  Thereafter, the torque deriving unit 216 derives a target torque that is a total value of torques that the engine 102 and the motor 104 should output so that the derived difference value becomes zero. At this time, when the derived gravity force is added, the target torque is large if it is uphill, and the target torque is small if it is downhill. The target torque (target engine torque and target motor torque) is set to an upper limit value from the output limit of the engine 102 or the motor 104, and the target torque is set so that the vehicle speed converges to the target vehicle speed over a predetermined time. It is set in the range below the upper limit.

  Here, when the engine 102 is driven during the constant speed running process, if the target torque becomes less than the creep torque of the engine 102, the vehicle speed becomes larger than the target vehicle speed due to the creep torque, so that the braking by the brake device 118 is performed. Will be necessary.

  Accordingly, the stop control unit 218 determines that the target torque derived by the torque deriving unit 216 is less than the creep torque of the engine 102 when the engine 102 is being driven during the constant speed running process. Give instructions to stop. When the HEVCU 200 receives an instruction to stop the engine 102 from the BCU 206 (stop control unit 218), the ECU 202 causes the ECU 202 to perform a stop control process for the engine 102. Note that the creep torque is a minimum output torque for maintaining the driving state of the engine 102 even when the engine 102 is reduced to the minimum output.

  In this way, when the engine 102 is driven during the constant speed running process, if the target torque becomes less than the creep torque of the engine 102, the stop control unit 218 stops the engine 102, so that the engine 102 is wasted. It is possible to suppress consumption of the brake device 118 while suppressing fuel consumption.

  Further, when the engine 102 is stopped during the constant speed running process, the stop control unit 218 determines that the battery of the motor 104 satisfies the remaining battery shortage condition when the target torque is equal to or higher than the creep torque of the engine 102. It is determined whether or not. Here, the battery remaining capacity shortage condition is, for example, that the SOC (State Of Charge) of the battery is below a threshold value. Further, it may be included in the condition that a target torque exceeding the upper limit value of the output of the motor 104 is set.

  When the battery of the motor 104 satisfies the battery remaining capacity shortage condition, the stop control unit 218 outputs an instruction to start the engine 102 to the HEVCU 200. As described above, the stop control unit 218 does not start the engine 102 even if the target torque is equal to or higher than the creep torque of the engine 102, and starts the engine 102 by satisfying the battery remaining capacity shortage condition. Therefore, even when the target torque frequently changes across the creep torque, the situation where the fuel consumption increases by repeatedly starting and stopping the engine 102 and the load on each component of the engine 102 increases is avoided. can do.

  The vehicle speed control unit 210 drives the motor 104 and the engine 102 to output the target torque when the engine 102 is driven (when not stopped) during the constant speed running process, and the engine 102 is stopped. If it is, the motor 104 is driven to output the target torque.

  Next, the flow of the vehicle control process for performing the above-described constant speed traveling process will be described in detail using a flowchart.

  FIG. 2 is a flowchart showing the flow of the vehicle control process. As shown in FIG. 2, the HEVCU 200 acquires a constant speed travel flag from the BCU 206, and determines whether or not the acquired constant speed travel flag is on (S300). If the constant speed travel flag is OFF (NO in S300), the vehicle control process is terminated.

  When the constant speed traveling flag is ON (YES in S300), the torque deriving unit 216 acquires the target vehicle speed set in the constant speed traveling process from the BCU 206 (S302). Then, the inclination information acquisition unit 212 acquires inclination information (S304). The relative inclination angle deriving unit 214 acquires information indicating the relative height of the traveling road ahead with respect to the position of the hybrid vehicle 100 from the GCU 208, and calculates the relative inclination angle from the continuous change in the height of the traveling road. Derived (S306).

  Then, the torque deriving unit 216 derives the inclination of the forward traveling road based on the inclination information and the relative inclination angle (S308), and derives the target torque so that the difference value between the vehicle speed and the target vehicle speed becomes zero. (S310).

  The stop control unit 218 determines whether or not the target torque derived by the torque deriving unit 216 is less than the creep torque of the engine 102 (S312). If the target torque is less than the creep torque of engine 102 (YES in S312), stop control unit 218 determines whether engine 102 is being driven (S314). If engine 102 is not being driven (NO in S314), the vehicle control process is terminated. If the engine 102 is being driven (YES in S314), the HEVCU 200 is instructed to stop the engine 102 (S316), and the vehicle control process is terminated.

  When the target torque is equal to or greater than the creep torque of engine 102 (NO in S312), stop control unit 218 determines whether engine 102 is stopped (S318). If the engine 102 is not stopped (NO in S318), the vehicle control process is terminated. If engine 102 is stopped (YES in S318), it is determined whether or not the battery of motor 104 satisfies the insufficient battery capacity condition (S320).

  When the battery of the motor 104 satisfies the remaining battery shortage condition (YES in S320), the stop control unit 218 outputs an instruction to start the engine 102 to the HEVCU 200 (S322). When the battery remaining capacity shortage condition is not satisfied (NO in S320), the vehicle control process is terminated.

  In the above-described embodiment, the case where the inclination information acquisition unit 212 is provided and the torque deriving unit 216 derives the target torque based on the inclination information in addition to the vehicle speed and the target vehicle speed has been described. However, the inclination information acquisition unit 212 is not an essential component, and the target torque may be derived without taking inclination information into consideration. However, by deriving the target torque in consideration of the inclination information, the target torque can be derived with high accuracy, and the stop timing of the engine 102 can be set appropriately.

  In the above-described embodiment, the case where the relative inclination angle deriving unit 214 is provided and the torque deriving unit 216 derives the target torque based on the relative inclination angle in addition to the vehicle speed, the target vehicle speed, and the inclination information has been described. However, the relative inclination angle deriving unit 214 is not an essential configuration, and the target torque may be derived without taking the relative inclination angle into consideration. However, by deriving the target torque in consideration of the relative inclination angle, the target torque can be derived with higher accuracy, and the stop timing of the engine 102 can be set more appropriately.

  Further, since the relative inclination angle derived by the relative inclination angle deriving unit 214 indicates the inclination of the traveling road ahead of the hybrid vehicle 100, for example, it is added to the derivation of the target torque even before the downhill, and the engine 102 The stop timing can be advanced to further suppress fuel consumption.

  In addition, the relative inclination angle derived by the relative inclination angle deriving unit 214 is derived over a wide range in the traveling direction of the traveling road ahead of the hybrid vehicle 100. Therefore, frequent changes in the derived value of the target torque are suppressed by statistical processing such as using the average value of the relative inclination angle in the traveling direction of the traveling road, even when the slope of the traveling road frequently changes. The frequency of starting and stopping the engine 102 can be suppressed.

  The present invention can be used for a vehicle control device for a vehicle driven by a motor and an engine.

DESCRIPTION OF SYMBOLS 100 Hybrid vehicle 102 Engine 104 Motor 120, 122 Imaging device 200 HEVCU (vehicle control device)
202 ECU (vehicle control device)
204 MCU (vehicle control unit)
206 BCU (vehicle control unit)
208 GCU (vehicle control unit)
210 Vehicle speed control unit 212 Inclination information acquisition unit 214 Relative inclination angle deriving unit 216 Torque deriving unit 218 Stop control unit

Claims (3)

In a vehicle control device for a vehicle driven by a motor and an engine,
A control unit, the control unit,
Performing a predetermined condition is satisfied, including the vehicle speed is below a predetermined speed, the constant speed running processing the vehicle speed to control the motor and the engine to a predetermined target vehicle speed,
Relative to the vehicle of the traveling road ahead of the vehicle derived based on the image captured by the imaging unit that images the front of the vehicle in response to detecting that the constant speed traveling process is being performed manner relative tilt angle is the tilt angle is derived based on the vehicle speed and the target vehicle speed, creep pre Symbol target torque Ru advancing the vehicle is a minimum output in order to maintain the driving state of the engine When the torque is less than that, the control process for stopping the engine is performed ,
If it is not detected that the constant speed running process is being performed, the control process is not performed . Wherein the control unit further acquires inclination information of the vehicle,
The vehicle control apparatus according to claim 1, wherein the target torque is derived based on the inclination information in addition to the relative inclination angle , the vehicle speed, and the target vehicle speed. The relative tilt angle claim wherein over a predetermined range of the traveling path is derived, and wherein the average value der Rukoto relative tilt angle with respect to the vehicle該走path based on the image The vehicle control device according to 1 or 2.

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