JP6619558B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle, and more particularly to a control device for a hybrid vehicle having an inertial traveling control function.

  In recent years, a hybrid vehicle (HEV) that can effectively improve the fuel consumption rate (fuel consumption) of a vehicle by using an engine and an electric motor in combination has been widely put into practical use. Various methods have been proposed for hybrid vehicles, but when hybrid vehicles are classified by drive method, they are mainly equipped with an engine and a generator for charging storage batteries and running with an electric motor while charging.・ Hybrid vehicles, parallel hybrid vehicles in which the engine and electric motor are arranged in parallel and capable of supplying driving force from both sides, and series parallel hybrid vehicles that have the advantages of both series and parallel systems It can be divided into three methods.

  When hybrid vehicles are functionally separated, in addition to an idling stop function, an acceleration assist function, and an energy regeneration function, a strong hybrid vehicle having an EV (electric vehicle) driving function and an engine are used as main power sources. And a mild hybrid vehicle (mHEV) that includes a relatively small electric motor and a storage battery and that exhibits an idling stop function, an acceleration assist function, and an energy regeneration function with a relatively simple configuration.

  A hybrid vehicle that employs any of the above-mentioned methods converts the kinetic energy that was conventionally discarded as heat by the brake to electric power by operating the electric motor as a generator during vehicle braking (deceleration). Charge the storage battery (regenerative braking / energy regeneration). For example, when starting or accelerating, the electric motor is driven by the power of the storage battery to assist the engine (or travel only by the electric motor), thereby improving the fuel efficiency.

  On the other hand, in order to further improve fuel efficiency, when the accelerator pedal is returned during traveling and the vehicle is coasting (coating), for example, the clutch provided between the engine and the drive wheels is released. Thus, there has been proposed a hybrid vehicle that performs inertial running control (coating control) in which the engine is disconnected from the drive system and fuel supply to the engine is stopped (fuel cut) (see, for example, Patent Document 1).

  Here, in Patent Document 1, in a hybrid vehicle traveling on a downward slope, coasting starts from an inertia traveling start point before the lowest point of the downward slope, and the inter-vehicle distance from other vehicles is a predetermined inter-vehicle distance. A technique is disclosed in which inertial running is stopped when it becomes less than this. According to this technique, fuel efficiency can be improved by starting inertial running from the near side of the lowest point. In addition, when the distance between the vehicle and another vehicle is reduced during inertial traveling, the safety of the vehicle can be ensured by stopping the inertial traveling.

JP 2012-131292 A

  By the way, in the mild hybrid vehicle (mHEV) described above, the electric motor is usually configured to be able to transmit power to and from the crankshaft of the engine. For this reason, when the inertial running control (coating control) described above is applied to a mild hybrid vehicle, the clutch is released and the engine is disconnected from the drive wheels during inertial running control. That is, energy regeneration cannot be performed. Therefore, there is a problem that improvement in fuel consumption is suppressed.

  The present invention has been made to solve the above-described problems, and provides a control device for a hybrid vehicle that can increase the amount of energy regenerated during coasting and can further improve fuel efficiency. With the goal.

A control device for a hybrid vehicle according to the present invention is a control device for a hybrid vehicle including an engine and an electric motor capable of transmitting power between the engine and a crankshaft of the engine. A clutch that is provided between the wheel and intermittently transmits a driving force transmitted from the engine crankshaft to the driving wheel of the vehicle, and when a predetermined inertial traveling control condition is satisfied, the clutch is released and The vehicle is not braked based on the inertial traveling control means for executing inertial traveling control for stopping the fuel supply, the external environment detecting means for detecting the external environment of the vehicle, and the external environment detected by the external environment detecting means And a braking prediction means for predicting whether or not regenerative braking is required after a predetermined time in the state, and the inertial traveling control means includes a braking prediction means. Accordingly, in a state where the vehicle is not being braked, when it is predicted that the regenerative braking is required after a predetermined time, even coasting control condition is satisfied, without initiating the execution of the coasting control, clutch It is characterized by prohibiting the release of.

  According to the control device for a hybrid vehicle according to the present invention, when the vehicle is predicted to be braked soon (for example, after a few seconds) (the brake is operated, that is, the regenerative brake is required) and / or soon If it is predicted that braking of the vehicle will be required (engine braking or regenerative braking is required), even if the inertial traveling control condition is satisfied, the release of the clutch is prohibited. Therefore, for example, it is possible to reduce the chance of shifting to the regenerative brake control immediately after the inertia running control (coating control) is started. Here, in order to shift from inertial running control to regenerative braking control, it takes time to re-engage the clutch and to synchronize the engine speed and the motor speed. As a result, the regeneration time can be increased. As a result, the amount of energy regeneration during inertial running can be increased, and fuel consumption can be further improved.

  In the hybrid vehicle control device according to the present invention, the external environment detection means detects whether there is a curve, a railroad crossing, a pedestrian crossing, or a temporary stop road sign in front of the vehicle, and the braking prediction means, It is preferable to predict that the vehicle will be braked when it is detected by the external environment detection means that there is a curve, a railroad crossing, a pedestrian crossing, or a temporary stop sign in front of the vehicle.

  In this case, when it is detected that there is a curve, a railroad crossing, a pedestrian crossing, or a temporary stop sign in front of the vehicle, the vehicle is predicted to be braked soon. Therefore, it can be predicted that the vehicle is braked more accurately. Therefore, for example, the opportunity to shift to regenerative brake control can be reduced by operating the brake immediately after inertial running control is started, and the regenerative time can be increased.

  In the hybrid vehicle control apparatus according to the present invention, the external environment detection means detects whether there is a moving obstacle ahead of the vehicle or whether the preceding vehicle has decelerated, and the braking prediction means It is preferable to predict that the vehicle is braked when the detection means detects that there is a moving obstacle ahead of the vehicle, or when deceleration of the preceding vehicle is detected.

  In this case, when it is detected that there is a moving obstacle in front of the vehicle, or when deceleration of the preceding vehicle is detected, it is predicted that the vehicle will be braked soon. Therefore, it can be predicted that the vehicle is braked more accurately. Therefore, for example, the opportunity to shift to regenerative brake control can be reduced by operating the brake immediately after inertial running control is started, and the regenerative time can be increased.

  In the control apparatus for a hybrid vehicle according to the present invention, the external environment detection unit detects the road surface gradient of the traveling road, the braking prediction unit detects that the road surface gradient detected by the external environment detection unit is a negative gradient, and is predetermined. It is preferable to predict that braking of the vehicle will be required if the value is below the value.

  In this case, when the road surface gradient of the traveling road is a negative road surface gradient and is equal to or less than a predetermined value (that is, in the case of a steep downhill), it is predicted that braking of the vehicle will be required soon. Therefore, it can be predicted more accurately that engine braking and regenerative braking will be required soon. Therefore, for example, immediately after the inertial running control is started, an engine brake, a regenerative brake, and the like are required, and the opportunity to shift to the regenerative brake control can be reduced, and the regenerative time can be increased.

  In the hybrid vehicle control device according to the present invention, the external environment detection unit detects the road surface friction coefficient of the traveling road, and the braking prediction unit detects that the road surface friction coefficient detected by the external environment detection unit is equal to or less than a predetermined value. It is preferable to predict that braking of the vehicle will be required.

  In this case, when the road surface friction coefficient is less than or equal to a predetermined value, it is predicted that braking of the vehicle will be required soon. Therefore, it can be predicted more accurately that engine braking and regenerative braking will be required soon. Therefore, for example, immediately after the inertia running control is started, the engine brake and the regenerative brake are required, and the opportunity to shift to the regenerative brake control can be reduced, and the regenerative time can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the energy regeneration amount at the time of coasting (at the time of coasting) can be increased, and it becomes possible to improve a fuel consumption more.

1 is a block diagram illustrating a configuration of a main part of a hybrid vehicle control device according to an embodiment and a hybrid vehicle to which the control device is applied. It is a flowchart which shows the process sequence of inertial running control (coasting control) by the control apparatus of the hybrid vehicle which concerns on embodiment. It is a timing chart which shows operation | movement of the control apparatus of the hybrid vehicle which concerns on embodiment when it approaches a curve. It is a timing chart which shows operation | movement of the control apparatus of the hybrid vehicle which concerns on embodiment when it approaches a curve.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, the configuration of the main part of a hybrid vehicle control device 1 according to the embodiment and a mild hybrid vehicle to which the control device 1 is applied will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a hybrid vehicle control device 1 and a main part of a mild hybrid vehicle to which the control device 1 is applied.

  The engine 10 may be of any type, but is, for example, a horizontally opposed in-cylinder four-cylinder gasoline engine. In the engine 10, air sucked from an air cleaner (not shown) is throttled by an electronically controlled throttle valve (hereinafter simply referred to as “throttle valve”) 13 provided in an intake pipe, passes through an intake manifold, and enters the engine 10. It is sucked into each formed cylinder. Here, the amount of air sucked from the air cleaner is detected by the air flow meter 61. Further, the throttle valve 13 is provided with a throttle opening sensor 14 for detecting the opening of the throttle valve 13. Each cylinder is provided with an injector for injecting fuel. Each cylinder is provided with an ignition plug for igniting the air-fuel mixture and an igniter built-in coil for applying a high voltage to the ignition plug. In each cylinder of the engine 10, an air-fuel mixture of the sucked air and the fuel injected by the injector is ignited by the spark plug and burned. The exhaust gas after combustion is exhausted through an exhaust pipe.

  In addition to the air flow meter 61 and the throttle opening sensor 14 described above, a cam angle sensor for determining the cylinder of the engine 10 is attached in the vicinity of the cam shaft of the engine 10. A crank angle sensor that detects the position of the crankshaft is attached in the vicinity of the crankshaft of the engine 10. These sensors are connected to an engine control unit (hereinafter referred to as “ECU”) 60 described later. The ECU 60 is also connected to various sensors such as an accelerator pedal sensor 62 that detects the amount of depression of the accelerator pedal, that is, the opening of the accelerator pedal, and a water temperature sensor that detects the temperature of the cooling water of the engine 10.

  A BSG (Belt Starter Generator) 11 is attached to one end (the vehicle front side) of the crankshaft 15 of the engine 10. Between the output shaft of the BSG 11 and the crankshaft 15, a belt 12 that transmits driving force is stretched. As a result, the BSG 11 can transmit power to and from the crankshaft 15 of the engine 10. The BSG 11 operates as a generator during braking (deceleration) of the vehicle, converts kinetic energy into electric power, and charges a storage battery (for example, a 42V battery) (regenerative braking function / energy regeneration function). The BSG 11 operates as a starter motor when restarting from an idling stop, for example, and cranks and restarts the engine 10 (starter motor function). Further, the BSG 11 operates as an electric motor at the time of starting or accelerating, for example, and assists the engine 10 to reduce the load on the engine 10 (motor assist function). That is, the BSG 11 functions as an electric motor described in the claims.

  The driving force from the engine 10 is converted at the other end (rear side of the vehicle) of the crankshaft 15 of the engine 10 via a torque converter 21 having a clutch function and a torque amplification function and a forward / reverse switching mechanism 27. Thus, a continuously variable transmission 20 that is output is connected.

  The torque converter 21 mainly includes a pump impeller 22, a turbine liner 23, and a stator 24. A pump impeller 22 connected to the crankshaft 15 generates an oil flow, and a turbine liner 23 disposed facing the pump impeller 22 receives the power of the engine 10 via the oil to drive the output shaft. The stator 24 located between the two rectifies the exhaust flow (return) from the turbine liner 23 and returns it to the pump impeller 22 to generate a torque amplifying action.

  The torque converter 21 has a lock-up clutch 25 that directly connects the input and the output. The torque converter 21 amplifies the torque of the driving force of the engine 10 and transmits it to the continuously variable transmission 20 when the lock-up clutch 25 is not engaged (in the non-lock-up state), and the lock-up clutch 25 is engaged. When driving (when locking up), the driving force of the engine 10 is directly transmitted to the continuously variable transmission 20.

  The forward / reverse switching mechanism 27 switches between forward rotation and reverse rotation (forward and reverse of the vehicle) of the drive wheels. The forward / reverse switching mechanism 27 mainly includes a double pinion planetary gear train 28, a forward clutch 29, and a reverse brake 30. The forward / reverse switching mechanism 27 is configured to be able to switch the transmission path of the engine driving force by controlling the states of the forward clutch 29 and the reverse brake 30.

  More specifically, when the D range (forward travel range) is selected, the forward clutch 29 is engaged and the reverse brake 30 is released, so that the rotation of the turbine shaft 26 directly changes to the primary shaft 32 described later. The vehicle can be moved forward by being transmitted. When the R range (reverse travel range) is selected, the forward clutch 29 is released and the reverse brake 30 is engaged to operate the planetary gear train 28 and reverse the rotation direction of the primary shaft 32. This makes it possible to drive the vehicle backward. When the N range or the P range is selected, the turbine clutch 26 and the primary shaft 32 are disconnected by releasing the forward clutch 29 and the reverse brake 30 (transmission of engine driving force is interrupted), The forward / reverse switching mechanism 27 is in a neutral state where power is not transmitted to the primary shaft 32.

  By using the forward clutch 29 and the reverse brake 30, inertia traveling control (coating control) is performed (details will be described later). That is, during inertial traveling control, the forward clutch 29 and the reverse brake 30 are released, and the engine 10 (crankshaft 15) is disconnected from the drive wheels. That is, the forward clutch 29 and the reverse brake 30 function as clutches described in the claims. The operations of the forward clutch 29 and the reverse brake 30 are controlled by a transmission control unit (hereinafter referred to as “TCU”) 40 and a valve body (control valve) 50 which will be described later.

  The continuously variable transmission 20 includes a primary shaft 32 connected to the turbine shaft (output shaft) 26 of the torque converter 21 via a forward / reverse switching mechanism 27, and a secondary shaft 37 disposed in parallel with the primary shaft 32. have.

  A primary pulley 34 is provided on the primary shaft 32. The primary pulley 34 includes a fixed pulley 34a joined to the primary shaft 32, and a movable pulley 34b mounted to be slidable in the axial direction of the primary shaft 32 so as to face the fixed pulley 34a. The cone surface interval of the pulleys 34a and 34b, that is, the pulley groove width can be changed. On the other hand, a secondary pulley 35 is provided on the secondary shaft 37. The secondary pulley 35 has a fixed pulley 35a joined to the secondary shaft 37, and a movable pulley 35b mounted to be slidable in the axial direction of the secondary shaft 37 so as to face the fixed pulley 35a. The width can be changed.

  Between the primary pulley 34 and the secondary pulley 35, a chain 36 for transmitting a driving force is suspended. By changing the groove width of the primary pulley 34 and the secondary pulley 35 and changing the ratio of the winding diameter of the chain 36 to the pulleys 34 and 35 (pulley ratio), the transmission ratio is changed steplessly. Here, if the winding diameter of the chain 36 around the primary pulley 34 is Rp, and the winding diameter around the secondary pulley 35 is Rs, the gear ratio i is expressed by i = Rs / Rp. Therefore, the gear ratio i is obtained by dividing the primary pulley rotation speed Np by the secondary pulley rotation speed Ns (i = Np / Ns).

  Here, a hydraulic chamber 34c is formed in the primary pulley 34 (movable pulley 34b). On the other hand, a hydraulic chamber 35c is formed in the secondary pulley 35 (movable pulley 35b). The groove width of each of the primary pulley 34 and the secondary pulley 35 is set and changed by adjusting the primary hydraulic pressure introduced into the hydraulic chamber 34c of the primary pulley 34 and the secondary hydraulic pressure introduced into the hydraulic chamber 35c of the secondary pulley 35. Is done.

  The hydraulic pressure for shifting the continuously variable transmission 20, that is, the primary hydraulic pressure and the secondary hydraulic pressure described above are controlled by a valve body (control valve) 50. The valve body 50 opens and closes an oil passage formed in the valve body 50 by using a spool valve and a solenoid valve (solenoid valve) that moves the spool valve, so that the hydraulic pressure discharged from an oil pump (not shown) is reduced. The pressure is adjusted and supplied to the hydraulic chamber 34 c of the primary pulley 34 and the hydraulic chamber 35 c of the secondary pulley 35. The valve body 50 also supplies hydraulic pressure to the forward / reverse switching mechanism 27 and the like.

  Shift control of the continuously variable transmission 20 is executed by the TCU 40. That is, the TCU 40 adjusts the hydraulic pressure supplied to the hydraulic chamber 34c of the primary pulley 34 and the hydraulic chamber 35c of the secondary pulley 35 by controlling the driving of the solenoid valve (electromagnetic valve) constituting the valve body 50 described above. The gear ratio of the continuously variable transmission 20 is changed. Further, the TCU 40 controls the drive of the forward clutch solenoid 50a that constitutes the valve body 50 described above, thereby adjusting the amount of ATF (Automatic Transmission Fluid) supplied / discharged to the forward clutch 29, and engaging the forward clutch 29. / Release. Similarly, the TCU 40 controls the drive of the reverse clutch solenoid 50 b constituting the valve body 50 to adjust the amount of ATF supplied / discharged to the reverse clutch 30 to engage / release the reverse clutch 30.

  The TCU 40 is connected to a primary pulley rotation sensor 57 that detects the rotation speed of the primary pulley 34, a secondary pulley rotation sensor 58 that detects the rotation speed (corresponding to the vehicle speed) of the secondary pulley 35, and the like. The TCU 40 includes, for example, an ECU 60 that comprehensively controls the engine 10 via a CAN (Controller Area Network) 100, a vehicle dynamic control unit (hereinafter referred to as “VDCU”) 70, a driving support device 80, and a navigation system 90. Etc. so that they can communicate with each other.

  The ECU 60 determines the cylinder from the output of the cam angle sensor described above, and obtains the engine speed from the change in the rotational position of the crankshaft detected by the output of the crank angle sensor. Further, the ECU 60 acquires various information such as the intake air amount, the accelerator pedal opening, the air-fuel ratio of the air-fuel mixture, and the water temperature based on the detection signals input from the various sensors described above. Then, the ECU 60 comprehensively controls the engine 10 by controlling the fuel injection amount, the ignition timing, and various devices such as the throttle valve 13 based on the acquired various pieces of information. The ECU 60 stops fuel injection to the engine 10 (performs fuel cut) during inertial running control (coasting control). Similarly, the ECU 60 stops fuel injection to the engine 10 during regenerative braking control.

  Further, the ECU 60 calculates the engine shaft torque (output torque) of the engine 10 based on the intake air amount detected by the air flow meter 61. And ECU60 transmits information, such as an engine speed, an engine shaft torque, and an accelerator pedal opening degree, to TCU40 via CAN100.

  Connected to the VDCU 70 are a brake switch 71 that detects whether or not the brake pedal is depressed, and a brake fluid pressure sensor 72 that detects the master cylinder pressure (brake hydraulic pressure) of the brake actuator 74. In addition, a wheel speed sensor 73 that detects the rotational speed (vehicle speed) of each wheel of the vehicle is connected to the VDCU 70.

  The VDCU 70 drives the brake actuator 74 in accordance with the operation amount (depression amount) of the brake pedal to brake the vehicle, and various vehicle behaviors (for example, a wheel speed sensor 73, a steering angle sensor, an acceleration sensor, a yaw rate sensor, etc.) ), And by controlling the brake by automatic pressurization and the torque control of the engine 10, the skid is suppressed and the vehicle stability at the time of turning is ensured. In addition, the VDCU 70 prevents wheel lock that occurs when braking suddenly or braking on a slippery road surface, and by keeping the slip rate of each wheel appropriate, it ensures the direction stability and steering performance during braking and is optimal. Anti-lock brake function (ABS function) that provides a good braking force, and traction that ensures vehicle stability and acceleration during start-up and acceleration by preventing slipping of the drive wheels caused by slippery road surfaces and excessive driving force It also has a control function (TCS function).

  The VDCU 70 transmits braking information (brake operation information) such as the detected brake switch 71 and brake fluid pressure, wheel speed (vehicle speed), and the like to the TCU 40 and the ECU 50 via the CAN 100.

  The driving support device 80 has a function (automatic braking function / pre-crash brake function) for detecting an external environment of the vehicle (for example, a driving environment in front of the vehicle) and performing an alarm or automatic braking (automatic braking) for a front obstacle. ing. The driving support device 80 also has a function of supporting the driving operation of the driver by performing follow-up control and warning control on the detected preceding vehicle.

  The driving support device 80 processes image data captured by, for example, a stereo camera 81 including a pair of cameras for acquiring an image in front of the vehicle, and, for example, the condition of the traveling road, the vehicle ahead of the vehicle, such as a preceding vehicle and an obstacle. Detects the driving environment (external environment). That is, the driving support device 80 functions as an external environment detection unit described in the claims.

  In particular, the driving support device 80 performs image processing on the image data and detects a lane (travel lane) based on a road marking line (white line) drawn on a road on which the vehicle travels. The driving support device 80 detects, for example, the presence or absence of a curve, the distance to the curve, the radius (curvature) of the curve, the width of the road, and the like based on the detected lane. In addition, the driving support device 80 extracts a preceding vehicle from the captured image by edge extraction or pattern recognition processing, etc., and based on the difference between the preceding vehicle positions in the left and right acquired images, the driving support device 80 is compared with the preceding vehicle by a triangulation method. The inter-vehicle distance is obtained, and the relative speed (whether the preceding vehicle has decelerated) is obtained from the amount of change with respect to the distance obtained at the previous frame.

  Similarly, the driving support device 80 detects whether or not there are, for example, a railroad crossing, a pedestrian crossing, a temporarily stopped road sign, and the like, and the distance to them if present. In addition, the driving support device 80 detects, for example, whether there are moving obstacles (for example, pedestrians, bicycles, etc.) in front of the vehicle, and if there are, obstacles to them.

  Furthermore, the driving assistance device 80 detects the road surface gradient of the traveling road. Further, the driving support device 80 recognizes, for example, whether the road surface is wet, snowy, or frozen based on the reflectance information of the road surface (that is, the road surface friction coefficient of the traveling road). ). Then, the driving support device 80 transmits the detected external environment information to the TCU 40 via the CAN 100.

  The car navigation system 90 detects the position of the host vehicle based on GPS satellite signals received by GPS (Global Positioning System). Further, the travel distance is calculated based on the vehicle speed information, and the traveling direction of the vehicle is detected according to the signal from the gyro sensor. In addition, the car navigation system 90 can store road information (that is, for example, whether there is a curve, a curve, etc.) from a built-in map information storage device such as a hard disk or a DVD disk. External environment information such as distance, curve radius, road width, railroad crossing, pedestrian crossing, stop sign, and road slope). That is, the car navigation system 90 also functions as an external environment detection unit described in the claims. The car navigation system 90 obtains the own vehicle position information and road information (for example, whether there is a curve, the distance to the curve, the curve radius, the road width, the railroad crossing, the pedestrian crossing, the stop sign, and the road surface via the CAN 100. External environment information such as gradient) is transmitted to the TCU 40.

  The TCU 40 includes a microprocessor that performs calculations, a ROM that stores programs for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, a backup RAM in which the stored contents are held by a battery, And an input / output I / F or the like. The TCU 40 receives the various external environment information, brake operation information, vehicle speed information, accelerator operation information, and the like described above from the ECU 60, the VDCU 70, the driving support device 80, and the navigation system 90 via the CAN 100.

  The TCU 40 automatically shifts the gear ratio steplessly in accordance with the driving state of the vehicle (for example, the accelerator pedal opening and the vehicle speed) according to the shift map. A shift map corresponding to the automatic shift mode is stored in the ROM in the TCU 40.

  Further, the TCU 40 has a function of further improving fuel efficiency by increasing the amount of energy regeneration during coasting (coasting). Therefore, the TCU 40 functionally includes a road surface gradient detection unit 41, a road surface frictional engagement detection unit 42, a braking prediction unit 43, and an inertia traveling control unit 44. In the TCU 40, the program stored in the ROM is executed by the microprocessor, thereby realizing the functions of the road surface gradient detection unit 41, the road surface frictional engagement detection unit 42, the braking prediction unit 43, and the inertia traveling control unit 44. The

The road surface gradient detector 41 detects the road surface gradient of the traveling road. That is, the road surface gradient detection unit 41 also functions as an external environment detection unit described in the claims. More specifically, as shown in the following equations (1) and (2), for example, the road surface gradient detection unit 41 includes a corrected acceleration sensor value obtained by adding a zero-point learning value to the vehicle acceleration, and the vehicle speed A road surface gradient is detected based on the difference from the differential value.
Road surface gradient value = corrected acceleration sensor value-vehicle speed differential value (1)
However, the corrected acceleration sensor value is calculated by the following equation (2).
Corrected acceleration sensor value = acceleration sensor value + 0-point learning value (2)
Here, the vehicle speed can be acquired based on the rotation speed of the output shaft of the continuously variable transmission 20 (or the average value of all wheel speeds).

  The road surface gradient detector 41 estimates the road surface gradient based on the driving force obtained from the output torque of the engine 10, the vehicle acceleration obtained from the differential value of the vehicle speed, and a preset vehicle weight. At the same time, the zero point of the longitudinal acceleration sensor is learned when the vehicle is traveling at a substantially constant speed on a flat road where the estimated road surface gradient is substantially zero (below a predetermined gradient). Then, as indicated by the above equation (2), the output value of the longitudinal acceleration sensor is corrected (added) at the learned zero point. The road surface gradient detected by the road surface gradient detection unit 41 is output to the braking prediction unit 43.

  The road surface friction coefficient detecting unit 42 acquires a road surface friction coefficient μ of the traveling road. That is, the road surface friction coefficient detection unit 42 also corresponds to the external environment detection means described in the claims. More specifically, the road surface friction coefficient detection unit 42 can determine (acquire) the road surface friction coefficient μ based on the deceleration during ABS operation, for example. That is, the road surface friction coefficient detection unit 42 determines that the road is low μ when the ABS is operated at a low deceleration according to the front and rear G during ABS operation, and is high when the ABS is operated at a high deceleration. It can be determined that it is a μ road. However, in this case, it is preferable to set a delay from the wheel speed ratio and not determine the road surface friction coefficient μ during the delay, for example, in order to prevent erroneous determination in a situation where the ABS operates momentarily in a manhole or the like.

  In addition, the road surface friction coefficient detection unit 42 uses the fact that the lateral G (lateral G estimated value) estimated from the wheel speed decreases when the tire slips, and looks at the difference between the lateral G sensor value and the lateral G estimated value, The road surface friction coefficient μ can also be estimated from the lateral G absolute value when the lateral G estimated value decreases. Further, the road surface friction coefficient detection unit 42 can also estimate the road surface friction coefficient μ based on the rack reaction force of the power steering. The road surface friction coefficient μ acquired by the road surface friction coefficient detection unit 42 is output to the braking prediction unit 43.

  Based on the external environment information detected by the driving support device 80, the navigation system 90, the road surface gradient detection unit 41, and / or the road surface friction detection unit 42, the brake prediction unit 43 is soon (for example, a few seconds later) Whether or not the vehicle is braked (the brake pedal is depressed, i.e. regenerative braking is required) and / or whether the vehicle needs to be braked soon (engine brake or regenerative brake is required) Predict. That is, the braking prediction unit 43 functions as a braking prediction unit described in the claims.

  More specifically, the braking prediction unit 43 is detected by the driving assistance device 80 and / or the navigation system 90 when there is a curve, a railroad crossing, a pedestrian crossing, or a stop road sign in front of the vehicle. The vehicle will be braked soon (the brake pedal will be depressed, that is, regenerative braking will be required).

  In addition, the braking prediction unit 43 is detected when the driving support device 80 detects that there is a moving obstacle such as a pedestrian or a bicycle in front of the vehicle, or when deceleration of the preceding vehicle is detected. Predict that the vehicle will be braked soon. At that time, the braking prediction unit 43 may predict that the possibility of braking is higher as the width is narrower in consideration of the width of the travel path. Similarly, considering the number and speed of moving obstacles such as pedestrians and bicycles, it may be predicted that the greater the number and the higher the speed, the higher the possibility of braking.

  Furthermore, the braking prediction unit 43 is a case where the road surface gradient detected by the driving support device 80, the navigation system 90, and / or the road surface gradient detection unit 41 is a negative gradient and is equal to or less than a predetermined value (that is, It is predicted that braking (engine braking and regenerative braking) will soon be required in the case of a steep downhill.

  Similarly, the brake prediction unit 43 is used when the road surface friction coefficient detected by the driving support device 80, the navigation system 90, and / or the road surface frictional engagement detection unit 42 is equal to or less than a predetermined value (that is, in the case of a low μ road). Predict that the vehicle will soon need braking. Note that the prediction result by the braking prediction unit 43 is output to the inertial traveling control unit 44.

  The inertial traveling control unit 44 satisfies a predetermined inertial traveling control condition (for example, the vehicle speed is equal to or higher than a predetermined speed, the accelerator pedal is not depressed, and the brake pedal is not depressed). In addition, the forward clutch 29 (and the reverse clutch 30) is released, and fuel supply to the engine 10 is stopped (fuel cut request information is sent to the ECU 60). That is, the inertial traveling control unit 44 functions as inertial traveling control means described in the claims.

  However, the inertial traveling control unit 44 may detect the braking of the vehicle (engine) when the braking prediction unit 43 predicts that the vehicle will be braked (for example, within a few seconds) (the brake pedal is depressed) soon. When it is predicted that a brake or a regenerative brake will be required, even if the inertia traveling control condition is satisfied, the forward clutch 29 (and the reverse clutch 30) is prohibited from being released (performance of inertia traveling control is prohibited). ). Then, after that, for example, when the brake pedal is depressed, the process immediately shifts to regenerative brake control.

  Next, the operation of the hybrid vehicle control device 1 will be described with reference to FIG. FIG. 2 is a flowchart showing a processing procedure of inertial running control (coating control) by the control device 1 of the hybrid vehicle. This process is repeatedly executed in the TCU 40 every predetermined time (for example, every 10 ms).

  First, in step S100, vehicle speed information, accelerator operation information, and brake operation information are read. Then, in the following step S102, based on the information read in step S100, whether or not the inertial running control execution condition is satisfied (that is, the vehicle speed is equal to or higher than a predetermined value and the accelerator pedal is not depressed, A determination is made as to whether or not the brake pedal is depressed. Here, if the inertial traveling control execution condition is satisfied, the process proceeds to step S104. On the other hand, when the inertial running control execution condition is not satisfied, the process once exits.

  In step S104, the external environment information described above is read. Since the external environment information is as described above, detailed description thereof is omitted here.

  Subsequently, in step S106, based on the external environment information read in step S104, it is predicted that the vehicle will be braked soon (for example, after a few seconds) (the brake pedal is depressed, that is, regenerative braking is required). And / or whether or not it is predicted that braking of the vehicle will soon be required (engine braking or regenerative braking is required).

  Here, if it is not predicted that the vehicle will be braked soon and it is not predicted that the vehicle will be braked soon, inertial running control is executed in step S108. That is, the forward clutch 29 (and the reverse clutch 30) is released and the fuel supply to the engine 10 is stopped. Then, in the subsequent step S110, a determination is made as to whether or not a predetermined inertial traveling control end condition is satisfied. Here, if the inertial travel control end condition is not satisfied, the process returns to step S108, and the inertial travel control is executed until the inertial travel control end condition is satisfied. On the other hand, when the inertial traveling control end condition is satisfied, the inertial traveling control is stopped in step S112, and then the process is temporarily exited.

  On the other hand, when the above-described step S108 is affirmed, that is, when it is predicted that the vehicle will be braked soon or that the vehicle needs to be braked soon, inertial traveling control is not executed as it is ( That is, the process is temporarily exited without releasing the forward clutch 29 and the reverse clutch 30).

  Next, timing charts showing an example of the operation of the above-described hybrid vehicle control device 1 are shown in FIGS. FIG. 3 is a timing chart showing the operation of the control device 1 of the hybrid vehicle when approaching a curve. In addition, the timing chart of a prior art is shown in the upper stage of FIG. 3 as a comparative example, and the timing chart of this embodiment is shown in the lower stage of FIG. FIG. 4 is a timing chart showing the operation of the hybrid vehicle control device 1 when it is predicted whether or not the vehicle will be braked with further consideration of the curve radius. Similar to FIG. 3, the upper part of FIG. 4 shows a timing chart of the related art as a comparative example, and the lower part of FIG. 4 shows the timing chart of the present embodiment.

  As shown in the upper part of FIG. 3, when approaching a curve from time t10, in the conventional technique, coasting control (coating control) is performed when the accelerator pedal is released at time t11. The forward clutch 29 (and the reverse clutch 30) is released. After that, when the vehicle further approaches the curve and the brake pedal is depressed at time t12 (that is, when the regenerative brake control execution condition is satisfied), switching from inertial travel control to regenerative brake control is started. In order to shift from the control to the regenerative brake control, it takes time to re-engage the forward clutch 29 and to synchronize the engine speed and the BSG speed, so there is a delay before the regenerative brake is actually applied. . Therefore, during that time (between times t12 and t13), power generation by the BSG11, that is, energy regeneration cannot be performed.

  On the other hand, as shown in the lower part of FIG. 3, according to the present embodiment, even when the accelerator pedal is released at time t11, the distance to the curve is short and the vehicle is braked soon (for example, several seconds later). When it is predicted that the inertial running control is performed, the forward clutch 29 is prohibited from being released. Therefore, when the brake pedal is depressed at time t12 (that is, when the regenerative brake control execution condition is satisfied), the regenerative brake operation can be started immediately.

  Next, with reference to FIG. 4, the operation when it is predicted whether or not the vehicle will be braked with further consideration of the curve radius will be described. Since the conventional technique does not originally predict whether or not the vehicle is braked, as shown in the upper part of FIG. 4, the movement is the same as the timing chart shown in the upper part of FIG. 3 described above.

  On the other hand, in the present embodiment, the set coasting control prohibition distance changes according to the curve radius. That is, if the vehicle speed is the same, the shorter the radius of the curve, the longer the coasting control prohibition distance, and it is predicted that the brake pedal will be stepped on (or regenerative braking will be required) at a farther position. . Therefore, in this case, as shown in the lower part of FIG. 4, when the depression of the accelerator pedal is released at time t21, the release of the forward clutch 29 is prohibited and the coasting regeneration control is executed once. Then, when the vehicle further approaches the curve and the brake pedal is depressed at time t22 (that is, when the regenerative brake control execution condition is satisfied), the regenerative brake control is executed immediately.

  As described above in detail, according to the present embodiment, when it is predicted that the vehicle will be braked soon (for example, after a few seconds) (the brake pedal is depressed, that is, regenerative braking is required), or If it is predicted that braking of the vehicle will soon be required (engine braking or regenerative braking is required), the release of the forward clutch 29 is prohibited even if the inertial traveling control condition is satisfied. Therefore, for example, it is possible to reduce the chance of shifting to the regenerative brake control immediately after the inertia running control (coating control) is started. Here, in order to shift from inertial running control to regenerative braking control, it takes time to re-engage the clutch and synchronize the engine speed and the BSG rotation speed. Thus, the regeneration time can be increased. As a result, the amount of energy regeneration during inertial running can be increased, and fuel consumption can be further improved.

  In particular, according to this embodiment, when it is detected that there is a curve, a railroad crossing, a pedestrian crossing, or a temporary stop sign in front of the vehicle, the vehicle is braked soon (the brake pedal is depressed). It is predicted. Therefore, it can be predicted that the vehicle is braked more accurately. Therefore, for example, the opportunity to shift to regenerative brake control can be reduced by operating the brake immediately after inertial running control is started, and the regenerative time can be increased.

  Further, according to the present embodiment, when it is detected that there is a moving obstacle in front of the vehicle, or when deceleration of the preceding vehicle is detected, it is predicted that the vehicle will be braked soon. Therefore, it can be predicted that the vehicle is braked more accurately. Therefore, for example, the opportunity to shift to regenerative brake control can be reduced by operating the brake immediately after inertial running control is started, and the regenerative time can be increased.

  According to the present embodiment, when the road surface gradient of the traveling road is a negative gradient and not more than a predetermined value (that is, a steep downhill), it is predicted that braking of the vehicle will be required soon. . Therefore, it can be predicted that engine brakes, regenerative brakes, and the like are required more accurately. Therefore, for example, immediately after the inertial running control is started, an engine brake, a regenerative brake, and the like are required, and the opportunity to shift to the regenerative brake control can be reduced, and the regenerative time can be increased.

  Further, according to the present embodiment, it is predicted that braking of the vehicle will be required soon when the road surface friction coefficient is equal to or less than a predetermined value. Therefore, it can be predicted that the engine brake and the regenerative brake are required more accurately. Therefore, for example, immediately after the inertial running control is started, an engine brake, a regenerative brake, and the like are required, and the opportunity to shift to the regenerative brake control can be reduced, and the regenerative time can be increased.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the above embodiment, the stereo camera 61 is used to detect the external environment. However, instead of the stereo camera, for example, a monocular camera, a millimeter wave radar, a laser radar, an ultrasonic sensor, or the like may be used. Good. A plurality of different sensors may be used in combination.

  In the above embodiment, based on the external environment information, whether or not the vehicle will be braked soon (the brake pedal is depressed) and / or whether or not the vehicle will be braked soon (engine braking or regenerative braking). However, the external environment information described above is merely an example and is not limited to the above embodiment.

  In the above-described embodiment, the forward / reverse switching mechanism 27 is arranged at the front stage of the primary pulley 34, but may be arranged at the rear stage of the secondary pulley 35.

  In the above embodiment, the hydraulic clutch is used as the forward clutch 29 and the reverse brake 30, but an electromagnetic type can be used, for example.

  In the above embodiment, the present invention is applied to a chain type continuously variable transmission (CVT). However, instead of the chain type continuously variable transmission, for example, a belt type continuously variable transmission or a toroidal type continuously variable transmission is used. It can also be applied to a transmission or the like. Moreover, it may replace with a continuously variable transmission (CVT) and may apply to a stepped automatic transmission (AT).

  In the above embodiment, the execution determination of the inertial traveling control is performed by the TCU 40. However, the inertial traveling control execution determination may be performed on the ECU 60 side, and the determination result may be transmitted to the TCU 40 via the CAN 100. Moreover, in the said embodiment, although ECU60 which controls the engine 10 and TCU40 which controls the continuously variable transmission 20 were comprised by separate hardware, you may comprise by integral hardware.

1 Control device for hybrid vehicle 10 Engine 11 BSG
12 belt 20 continuously variable transmission 21 torque converter 27 forward / reverse switching mechanism 28 planetary gear train 29 forward clutch 30 reverse brake 34 primary pulley 35 secondary pulley 36 chain 40 TCU
41 Road surface gradient detection unit 42 Road surface frictional engagement detection unit 43 Brake prediction unit 44 Inertia travel control unit 50 Control valve (valve body)
60 ECU
70 VDCU
71 Brake Fluid Pressure Sensor 72 Wheel Speed Sensor 73 Brake Actuator 80 Driving Support Device 90 Navigation System 100 CAN

Claims (5)

In a control apparatus for a hybrid vehicle comprising an engine and an electric motor capable of transmitting power between the engine and a crankshaft of the engine,
A clutch that is provided between the crankshaft of the engine and a drive wheel of the vehicle, and interrupts a driving force transmitted from the crankshaft of the engine to the drive wheel of the vehicle;
Inertial traveling control means for executing inertial traveling control for releasing the clutch and stopping fuel supply to the engine when a predetermined inertial traveling control condition is satisfied;
An external environment detection means for detecting the external environment of the vehicle;
Braking prediction means for predicting whether regenerative braking is required after a predetermined time in a state where the vehicle is not braked based on the external environment detected by the external environment detection means,
The inertial traveling control means may be configured to satisfy the inertial traveling control condition when the braking prediction means predicts that regenerative braking is required after a predetermined time in a state where the vehicle is not braked. A hybrid vehicle control device that prohibits release of the clutch without starting execution of the inertial running control . The external environment detection means detects whether there is a curve, a railroad crossing, a pedestrian crossing, or a temporary stop road sign in front of the vehicle,
The braking prediction means predicts that the vehicle will be braked when the external environment detection means detects that there is a curve, a railroad crossing, a pedestrian crossing, or a temporary stop road sign ahead of the vehicle. The control apparatus of the hybrid vehicle of Claim 1 characterized by these. The external environment detection means detects whether there is a moving obstacle in front of the vehicle or whether the preceding vehicle has decelerated,
The braking prediction means predicts that the vehicle is braked when the external environment detection means detects that there is a moving obstacle ahead of the vehicle or when the deceleration of the preceding vehicle is detected. The hybrid vehicle control device according to claim 1. The external environment detection means detects a road surface gradient of the traveling road,
The braking prediction means predicts that braking of the vehicle is required when the road surface gradient detected by the external environment detection means is a negative gradient and not more than a predetermined value. The control apparatus of the hybrid vehicle of any one of 1-3. The external environment detection means detects a road surface friction coefficient of the traveling road,
5. The vehicle braking prediction apparatus according to claim 1, wherein the braking prediction unit predicts that braking of the vehicle is required when a road surface friction coefficient detected by the external environment detection unit is a predetermined value or less. The control apparatus of the hybrid vehicle described in 2.

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