JP2010089584A - Vehicle controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a driver to optionally select starting control after automatically stopping an engine. <P>SOLUTION: If automatic stopping requirements are not met after the automatic stopping requirements have been met and an engine has been stopped, it is checked whether or not a brake is not turned on accompanied by the release of a brake pedal (S4), if the brake is not turned on, a starter is actuated to initiate the cranking of the engine (S5), and it is checked whether or not engine speed Ne has become equal to or higher than a set speed Ns (S6). Once Ne is equal to or higher than Ns, the clutch hydraulic pressure of an automatic transmission is started to rise by the inclination of a pressure buildup speed that matches a mode selected by the driver, and brake hydraulic pressure is started to be released by the inclination of a pressure drop speed that matches the mode selected (S7). Thereafter, once the clutch hydraulic pressure reaches a set value, the clutch hydraulic pressure is switched to hydraulic pressure for complete fastening (S9), and the process is ended when the brake hydraulic pressure reaches the set value (S10). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device that allows a driver to select start control when an engine is automatically stopped and then restarted.

  In recent years, for the purpose of reducing exhaust gas or improving fuel efficiency, vehicles having a so-called idling stop system that stops the engine when the vehicle is stopped or when driving force is unnecessary have been developed. A vehicle equipped with this idling stop system automatically stops driving the engine and detects a re-start operation such as depressing the accelerator when a condition for determining that the vehicle is stopped or driving force is unnecessary is established. Restart the engine.

  In a vehicle equipped with such an idling stop system, the engine is stopped regardless of the driver's intention. Therefore, the entire system that operates depending on the driving of the engine is stopped when the engine is stopped, and the engine is restarted. Along with this, the operation starts. For this reason, there is a possibility that an operation shock of the transmission or the like due to a change in the operation state may occur, and in a vehicle with an automatic transmission, the reverse of the vehicle due to the disappearance of creep may occur due to the stop of the engine. There is. As countermeasures, there have been proposed control for reducing the shock of the engine and the automatic transmission when the engine is restarted, control for interlocking with the automatic brake, and the like.

For example, Patent Document 1 discloses a technique for changing the braking force according to the engine speed and torque for the purpose of preventing a feeling of popping out when starting the engine when the automatic transmission is operated from N position to D position. Has been proposed. Patent Document 2 proposes a technique for performing rapid pressure increase control when the engine speed becomes a predetermined value or more in order to reduce the engagement shock of the starting clutch at the time of restart.
JP 2000-127927 A JP 11-303981 A

  As described above, in a vehicle equipped with a conventional idling stop system, in order to prevent the driver from feeling uncomfortable due to a stop not intended by the driver, a shock due to restart, etc., the engine is started. Controls such as reducing vibration at the time and gradual clutch engagement of the automatic transmission are adopted. However, since such control can be an element that causes a delay in restart, it is not necessarily a preferable control for a driver who does not like a shock or the like but does not like a delay in starting.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle control device that allows a driver to arbitrarily select start control after an engine is automatically stopped.

  To achieve the above object, the present invention provides a mode selection unit that selects a predetermined control mode including at least a first mode and a second mode based on a driver's operation, and a forward position of an automatic transmission. A first control unit that automatically stops the engine when a predetermined stop condition including that is selected is satisfied, and restarts the engine that is automatically stopped when the predetermined restart condition is satisfied; When the first mode is selected, when the engine is restarted, the pressure increase rate of the pressure medium enabling the power transmission by engaging the engagement element of the automatic transmission is A second control unit configured to make the pressure increase rate faster than the selected speed; and a brake hydraulic pressure is maintained in an automatic stop state of the engine to maintain a vehicle stop state; When releasing the stop state of the vehicle by reducing the hydraulic pressure, the pressure reduction speed of the brake hydraulic pressure when the first mode is selected is greater than the pressure reduction speed when the second mode is selected. And a third control unit for speeding up.

  According to the present invention, the driver can arbitrarily select the start control after the engine is automatically stopped, the vehicle is agile, the vehicle is started with less shock, etc. according to the driver's preference and convenience. Can be made possible.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 relate to a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a vehicle control system, FIG. 2 is an explanatory diagram showing a pressure increase speed for each mode of clutch hydraulic pressure, and FIG. FIG. 4 is a flowchart of cooperative control, FIG. 5 is an explanatory diagram showing various waveforms in cooperative control, and FIG. 6 is an explanatory diagram showing waveforms of brake hydraulic pressure and clutch hydraulic pressure.

  In FIG. 1, reference numeral 1 denotes an engine mounted on a vehicle (not shown), and an automatic transmission 3 is connected to an output shaft of the engine 1 via a motor generator 2. The motor generator 2 is directly connected to the output shaft of the engine 1 and functions as a starter at the start, and also functions as a generator after the engine is started. After the engine 1 is automatically stopped by a temporary stop of the vehicle, When the vehicle is restarted, the engine 1 is cranked by the motor generator 2 and the engine 1 is restarted.

  The automatic transmission 3 includes a torque converter and a starting clutch, and is a control in which various control valves for controlling the pressure of oil (pressure medium) supplied to each mechanism portion and engaging element of the power transmission mechanism are integrally formed. The valve body 3a is accommodated in the oil pan. By this control valve body 3a, engaging elements such as clutches and brakes are individually supplied and discharged and engaged / disengaged, and the power from the engine 1 is transmitted at a predetermined shift speed.

  Further, the above vehicle is provided with a plurality of control units that constitute a system control system. Each of the plurality of control units includes a microcomputer and peripheral circuits, and includes an engine control unit 10 that controls the engine 1, a power control unit 20 that manages driving of the motor generator 2 and charge / discharge of a battery (not shown), A transmission control unit 30 that controls the automatic transmission 3, a brake control unit 50 that controls a brake device 40 that performs braking by restraining rotation of wheels, a mode selection unit 60 that selects a control mode to be described later, and the like. Each of these units is connected to an in-vehicle network 100 such as a CAN (Controller Area Network), and is configured to be able to exchange control information with each other.

  The engine control unit 10 is connected to various sensors such as an accelerator position sensor 11 that detects the amount of depression of the accelerator pedal, an engine speed sensor 12 that detects the engine speed, and a vehicle speed sensor 13 that detects the vehicle speed. The engine control unit 10 controls the amount of fuel supplied to the engine 1 (fuel injection amount), ignition timing, and the like based on information from these sensors and information acquired via the in-vehicle network 100.

  The power control unit 20 is connected to an inverter 21 that drives the motor generator 2 and a battery (not shown). The power control unit 20 receives an engine start control command and various control information from the engine control unit 10 via the in-vehicle network 100, and drives the motor generator 2 via the inverter 21 when the engine 1 is started. While running, the regenerative electric power from the motor generator 2 is collected in the battery via the inverter 21, and the charge / discharge current of the battery is monitored to perform power management.

  The transmission control unit 30 is connected to an inhibitor switch 31 for detecting a shift shift position, a plurality of hydraulic sensor groups 32 for detecting the hydraulic pressure of oil supplied to each engagement element of the automatic transmission 3, and the like. Various control information from the engine control unit 10, the brake control unit 50, and the like is input via 100. The transmission control unit 30 outputs a control signal for each control valve of the control valve body 3a based on the control information, and performs the shift control of the automatic transmission 3.

  The brake control unit 50 is connected to a brake hydraulic pressure sensor 51 that detects the brake hydraulic pressure, a brake switch 52 that turns ON / OFF the brake hydraulic pressure threshold and detects the brake operating state. The brake control unit 50 is a signal from these sensors and switches. And based on the various control information acquired via the in-vehicle network 100, the brake device 40 which consists of a hydraulic unit provided with the pressurization valve, the pressure-reduction valve, the pressure increase valve, etc. is controlled.

  The brake control unit 50 has a hill hold function that activates the brake regardless of the driver's brake operation. When the engine is automatically stopped and the vehicle is stopped, the master cylinder hydraulic pressure of the brake device 40 is reduced. The brake operating pressure is maintained to prevent the vehicle from retreating on a slope.

  The mode selection unit 60 functions as a mode selection unit that selects a control mode for the engine 1, the automatic transmission 3, and the brake device 40 according to the preference and convenience of the driver when the vehicle is restarted after the engine is automatically stopped. An operation unit 61 is connected to receive an operation input for mode selection by the driver. The operation unit 61 includes a dial, a switch, a touch panel, and the like, and outputs a signal corresponding to the operation state of the driver to the mode selection unit 60. The mode selection unit 60 selects a control mode corresponding to the signal from the operation unit 61, and transmits information on the selected control mode to other units via the in-vehicle network 100.

  For example, when the operation unit 61 is configured with a dial volume that outputs voltages corresponding to a plurality of control modes, when the driver operates the dial and rotates it to the indicated position corresponding to the first mode, the dial position is set. A voltage signal in a corresponding state is output from the operation unit 61 to the mode selection unit 60, and a corresponding control mode is selected. Further, when the operation unit 61 is configured by a plurality of switches connected to a matrix circuit, for example, a logic signal corresponding to the switch operated by the driver is output from the operation unit 61 to the mode selection unit 60, The corresponding control mode is selected.

  Although FIG. 1 shows an example in which the mode selection unit 60 is configured as an independent unit, the function of the mode selection unit 60 is not provided with the independent mode selection unit 60, and the functions of the engine control unit 10 and transmission You may make it comprise as one function in other units, such as the control unit 30. FIG.

  In the present embodiment, the modes selected by mode selection unit 60 are the three control modes of the first to third modes. In the vehicle system configured by each of the above units, engine control unit 10 and The power control unit 20 is a first control unit, the transmission control unit 30 is a second control unit, and the brake control unit 50 is a third control unit, and these first to third control units control each other in cooperation with each other. The system control according to the mode selected by the driver is realized.

  Specifically, when the engine 1 is automatically stopped, such as when the vehicle is temporarily stopped, the brake device 40 is automatically operated by the hill hold function of the brake control unit 50, and the vehicle is maintained in the stopped state. Thereafter, when the accelerator is depressed to restart the vehicle, the engine 1 is restarted via the motor generator 2. When the engine 1 is restarted, the engagement element (the present embodiment) of the automatic transmission 3 is restarted. In the embodiment, the oil pressure (clutch hydraulic pressure) supplied to the starting clutch) is controlled to increase at a speed set corresponding to the mode selected by the driver from the first to third modes, Further, the brake hydraulic pressure is controlled to decrease at a speed set corresponding to the mode selected by the driver.

  As shown below, the first to third modes are modes set in consideration of start performance after engine restart and shock reduction, respectively, and can be selected according to the preference and convenience of the driver. It has become.

[First mode]
This mode prioritizes agile start after engine restart, and agile start is enabled by advancing the engagement timing of the start clutch of the automatic transmission 3 and the brake release timing. For this reason, in the first mode, the rate of increase of the clutch hydraulic pressure is made faster than in the second and third modes, and the rate of decrease in the brake hydraulic pressure is made faster than in the second and third modes.

  That is, as shown in FIG. 2, in the first mode, the rising inclination of the clutch hydraulic pressure Ptm is set to the steepest inclination a1, and a slight shock is allowed to minimize the start clutch engagement time. In addition, as shown in FIG. 3, the slope of the fall of the brake hydraulic pressure Pb is set to the steepest slope b1, the brake release timing is the shortest, and the time from the start of the brake hydraulic pressure by the hill hold function to the release of the brake Is also the shortest.

  Furthermore, in the first mode, when the engine is restarted, the ignition start timing of the engine is made faster than those in the second and third modes, and ignition in the first compression stroke is enabled to minimize the start time. By this control for advancing the ignition start timing, the rotation can be quickly increased after the engine is started, and the start-up of the torque at the time of starting can be accelerated to start the vehicle more quickly.

[Second mode]
The second mode is a mode that considers shock reduction at the time of start rather than agile start after engine restart, and as shown by the inclination a2 in FIG. It is set more gently than in the first mode, and the shock at the time of start is made minute. In the second mode, the engagement time of the starting clutch is the same as the engagement time in normal control.

  Further, as shown by the inclination b2 in FIG. 3, the rate of decrease in the brake hydraulic pressure Pb is set relatively more gently than in the first mode, and the brake release timing is the normal control timing. The time from the start of the brake hydraulic pressure by the hill hold function to the release of the brake is also the normal control time. The ignition start timing of the engine is set so as to be ignited after exceeding the roll resonance, and the start time, the rotation increase after the start, and the rising of the torque at the start are the same as in the normal control state.

[Third mode]
The third mode is a mode for further reducing the shock than the second mode. The clutch hydraulic pressure increase rate is made slower than the second mode, and the brake hydraulic pressure decrease rate is set to be lower than that of the second mode. By slowing down, the shock is reduced to the extent that the driver does not feel the shock.

  In the third mode, as shown by the inclination a3 in FIG. 2, the rising speed of the clutch hydraulic pressure Ptm is set most gently in each mode, and the engagement time of the starting clutch is longer than usual. The shock at the start is substantially zero.

  Further, the decrease rate (falling slope) of the brake hydraulic pressure Pb is set most gradually in each mode, as shown by the slope b3 in FIG. The time from the start of brake hydraulic pressure to the release of the brake is also set longer than usual. The ignition start timing of the engine is set so as to be ignited after exceeding the roll resonance as in the second mode, and the start time is the same as in the second mode, but there is no run-up of the rotation after the start. In addition, the torque rise at the time of starting is also slower than usual.

  The control in each mode described above is realized as cooperative control of the entire vehicle system by each unit. Next, program processing related to the cooperative control of the entire system will be described with reference to the flowchart of FIG.

  First, in the first step S1, the engine control unit 10 checks whether or not an automatic engine stop condition is satisfied based on signals from sensors and switches and control information via the in-vehicle network 100. The engine automatic stop condition is, for example, a condition in which all of the condition that the accelerator is fully opened, the condition that the shift position is the forward position, the condition that the brake is ON, and the condition that the vehicle speed is 0 (vehicle stop state) are satisfied. When any of the conditions is not satisfied, the automatic stop condition is not satisfied.

  When the automatic stop condition in step S1 is satisfied, the process proceeds from step S1 to step S2. In step S2, the fuel injection to the engine is stopped, the ignition is cut, the engine is stopped, and the process is exited.

  On the other hand, if the automatic stop condition is not satisfied in step S1, the process proceeds from step S1 to step S3 to check whether the engine is stopped. Then, if the engine is not stopped, the process is exited. If the engine is stopped, the process proceeds to step S4 and subsequent steps to restart the engine.

  In the process of step S4, the brake control unit 50 checks whether or not the brake pedal is released based on a signal from the brake hydraulic pressure sensor 51. Then, when the brake pedal is not released (when the brake is ON), this process is terminated, and when the brake pedal is released (when the brake is no longer ON), the engine control is performed from the brake control unit 50. Brake OFF is transmitted to the unit 10.

  In step S5, the engine control unit 10 transmits a cranking instruction to the power control unit 20, energizes the motor generator 2 through the power control unit 20, operates as a starter, and starts engine cranking. In step S6, it is checked whether or not the engine speed Ne is equal to or higher than a predetermined set speed Ns after complete explosion (for example, 1000 rpm). If Ne <Ns, the process returns to step S5, and Ne ≧ Ns. The transmission control unit 30 and the brake control unit 50 are notified of the engine complete explosion, and the process proceeds to step S7 and subsequent steps.

  In the process of step S7, the transmission control unit 30 and the brake control unit 50 each perform control in accordance with the mode selected by the driver. In other words, the transmission control unit 30 starts to increase the clutch hydraulic pressure of the automatic transmission 3 with the gradient of the pressure increase speed in accordance with the selected mode via the control valve body 3a, and the brake control unit 50 selects the selected mode. The brake hydraulic pressure of the brake device 40 is started to be released with the inclination of the pressure decrease speed in accordance with.

  Thereafter, in step S8, it is checked whether or not the clutch hydraulic pressure has reached a set value. If the clutch hydraulic pressure has not reached the set value, the process of step S7 is continued. When the clutch hydraulic pressure reaches the set value, the clutch hydraulic pressure is switched to the fully engaged hydraulic pressure in step S9, and the brake hydraulic pressure is set in step S10. This process is terminated when the brake hydraulic pressure reaches the set value.

  The operation of the system according to the above procedure will be described with reference to FIGS. When the engine is automatically stopped and the accelerator is depressed from a state where the vehicle is stopped by the brake hill hold, it is determined that the engine is restarted, and a cranking instruction is output from the engine control unit 10 to crank the engine. .

  When the engine speed increases due to the cranking of the engine and exceeds the set speed after the complete explosion, the pressure increase control of the starting clutch of the automatic transmission 3 is started, and the pressure according to the mode selected by the driver is started. The clutch hydraulic pressure is increased at the rising speed. Further, at this time, the hill hold of the brake device 40 is released and the master cylinder hydraulic pressure is set to 0, and the brake hydraulic pressure is released at a pressure decreasing speed in accordance with the selected mode as shown in FIG. The brake hydraulic pressure is released in coordination with the increased pressure.

  As described above, when the first mode is selected, the rising speed of the clutch hydraulic pressure and the decreasing speed of the brake hydraulic pressure are made the fastest, the start timing of the starting clutch is advanced, and the brake release timing is advanced. And agile start is possible. In addition, when the second and third modes are selected, the clutch hydraulic pressure increase speed and the brake hydraulic pressure decrease speed are moderated, and the shock at the time of start is small (second mode) or substantially. 0 (third mode) is set. Thereafter, when the clutch hydraulic pressure reaches the set value, the clutch hydraulic pressure is set to the command hydraulic pressure for completely engaging the starting clutch, and this control is finished.

  As described above, in the present embodiment, when the vehicle starts after the engine is automatically stopped, depending on the driver's preference and convenience, a slight shock is allowed to start agile, or the start performance is somewhat Even if it is sacrificed, it is possible to select whether the level of shock is small or not felt at all, and a flexible and convenient system can be obtained. In addition, when the mode that prioritizes shock reduction over the start performance is selected, the brake hydraulic pressure release control is implemented in coordination with the clutch hydraulic pressure increase control, thus preventing the feeling of popping out when the vehicle starts. It does not give the driver a sense of incongruity.

  Next, a second embodiment of the present invention will be described. FIG. 7 is a configuration diagram of a vehicle power supply system according to a second embodiment of the present invention.

  The second mode is applied to a vehicle that improves power supply characteristics by connecting an auxiliary power source in parallel to the main power source in addition to the main power source of the vehicle.

  That is, as shown in FIG. 7, the power supply system of the vehicle in the second embodiment is configured such that an auxiliary power supply composed of a large-capacity capacitor 6 is connected in parallel to a lead battery 5 that is a main power supply, A relay RY <b> 1 is interposed between the load 7 and the relay RY <b> 2 between the relay RY <b> 1 and the vehicle load 7 and the positive electrode side of the lead battery 5.

  Further, the positive contact side of the lead battery 5 is connected to the fixed contact side terminal of the magnet switch of the starter 8 and to the rectification output terminal of the alternator 9 via the relay RY2. Further, the rectification output terminal of the alternator 9 is connected to the positive electrode side of the capacitor 6 via the relay RY1, and regenerative energy at the time of deceleration is stored in the capacitor 6 to compensate for the lead battery 5 which is not good at rapid charge. The power generation load of the alternator 9 is reduced to improve fuel efficiency. The starter 8 and the alternator 9 may be the motor generator 2 described in the first embodiment.

  In the second mode, the engine control, the transmission control, and the brake control are the same as those in the first mode. However, when the engine is restarted, the lead battery 5 alone or the lead battery is selected according to the mode selected by the driver. Power is supplied from both 5 and the capacitor 6 to the starter 8 to crank the engine.

  Specifically, when the first mode is selected, both relays RY1 and RY2 are turned ON to close the respective relay contacts, and power is supplied to starter 8 from both lead battery 5 and capacitor 6. And crank the engine. Thereby, the engine can be cranked more stably and strongly, and the engine can be started in a shorter time.

  When the second mode or the third mode is selected, the relays RY1 and RY2 are turned OFF to open the relay contacts, and the starter 8 is supplied with power from only the lead battery 5 to crank the engine. Let In this case, the starter 8 cranks the engine at a normal speed, but it is possible to suppress wear of the starter brush.

  In the second mode, as in the first mode, when starting the vehicle after the engine is automatically stopped, not only can the driver select according to the preference and convenience of the driver, but also the starter according to the selected mode. The power to be supplied can be changed. Therefore, more effective start control can be performed by a synergistic effect with the engine start control.

1 is a schematic configuration diagram of a vehicle control system according to a first embodiment of the present invention. As above, an explanatory diagram showing the pressure increase speed for each clutch hydraulic pressure mode Same as above, explanatory diagram showing the pressure drop speed for each brake hydraulic pressure mode Same as above, flowchart of cooperative control Same as above, explanatory diagram showing various waveforms in cooperative control Same as above, explanatory diagram showing waveforms of brake hydraulic pressure and clutch hydraulic pressure A configuration diagram of a vehicle power supply system according to a second embodiment of the present invention.

Explanation of symbols

1 Engine 2 Motor generator (starter)
3 Automatic transmission 5 Lead battery (main power supply)
6 Capacitor (auxiliary power supply)
8 Starter 10 Engine control unit (first control unit)
20 Power control unit (first control unit)
30 Transmission control unit (second control unit)
40 Brake device 50 Brake control unit (third control unit)
60 mode selection unit (mode selection unit)
61 Operation unit

Claims (8)

A mode selection unit that selects a predetermined control mode including at least a first mode and a second mode based on a driver's operation;
A first engine that automatically stops the engine when a predetermined stop condition including that the forward position of the automatic transmission is selected is satisfied, and restarts the engine that is automatically stopped when the predetermined restart condition is satisfied. A control unit of
When the first mode is selected, when the engine is restarted, the pressure increasing speed of the pressure medium that enables power transmission by engaging the engagement element of the automatic transmission is set to the second mode. A second control unit that makes the pressure increase rate faster than when the is selected,
The first mode is selected when the brake hydraulic pressure is maintained while the engine is automatically stopped to maintain the vehicle stopped state, and when the engine is restarted, the brake hydraulic pressure is decreased to release the vehicle stopped state. A vehicle control device comprising: a third control unit configured to make a pressure decrease rate of the brake hydraulic pressure when the second mode is set higher than a pressure decrease rate when the second mode is selected.   When the first mode is selected, the first control unit makes the ignition start timing of the engine earlier than the ignition start timing when the second mode is selected when the engine is restarted. The vehicle control device according to claim 1.   When the first mode is selected, the second control unit determines a time period from when the engine restart condition is satisfied until the pressure medium starts to increase in pressure. The vehicle control device according to claim 1 or 2, wherein the time is shorter than a time until the pressure medium starts to rise when selected.   When the first mode is selected, the third control unit determines the time from when the engine restart condition is satisfied until the pressure decrease of the brake hydraulic pressure is started in the second mode. The vehicle control device according to claim 1, wherein the time is shorter than a time until the start of pressure drop of the brake hydraulic pressure when selected.   The mode selection unit includes an operation unit that is operated to a predetermined state including at least a first state and a second state by a driver of the vehicle, and the operation unit is operated to the first state. 5. The device according to claim 1, wherein when the operation unit is operated, the first mode is selected, and when the operation unit is operated in the second state, the second mode is selected. 6. Vehicle control device.   When the first mode is selected, the first control unit determines the degree of increase in the output of the engine with respect to the accelerator depression amount, and the degree of the accelerator depression with respect to the accelerator depression amount when the second mode is selected. The vehicle control device according to any one of claims 1 to 5, wherein the vehicle output device is larger than a degree of increase in engine output. The mode selection unit can select a third mode different from the first mode and the second mode,
When the third mode is selected, the second control unit indicates the pressure increase rate of the pressure medium when the engine is restarted, and the pressure increase rate when the first mode is selected. Slower,
When the third mode is selected, the third control unit determines a decrease rate of the brake hydraulic pressure when the engine is restarted, and the brake hydraulic pressure when the first mode is selected. The vehicle control device according to any one of claims 1 to 6, wherein the vehicle control device is slower than the lowering speed. The vehicle includes an auxiliary power source connected in parallel via a relay to a main power source that supplies power to a vehicle load,
When the first mode is selected, the first control unit controls the relay so that power is supplied from both the main power source and the auxiliary power source to the starter, and restarts the engine. The vehicle control device according to claim 1, wherein the vehicle control device is a vehicle control device.

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