JP7420184B2 - vehicle control system - Google Patents

Description

The present invention relates to a vehicle control system for controlling coasting of a vehicle.

Conventionally, in order to save energy in automobiles (that is, to reduce fuel and electric power consumption), a clutch device was installed on the drive power transmission path between the power source such as an engine or motor and the drive wheels. A vehicle is known that enables coasting during high-speed cruising by controlling switching between the engaged and disconnected states of this clutch device (for example, see Japanese Patent Laid-Open No. 2014-136476). Note that coasting is sometimes called, for example, coasting or sailing.

Japanese Patent Application Publication No. 2014-136476

However, in conventional systems, the information used to determine whether or not to coast (for example, information such as driving force and acceleration/deceleration) must be estimated from vehicle speed, accelerator opening, etc. There is a lot of information that is not available. On the other hand, before implementing a system in a vehicle, for each of these pieces of information, tedious tasks such as building logic and models for estimating, matching the model with actual measurements, and setting safety factors for estimated values are necessary. need to be done. Therefore, since there is a large amount of information that must be estimated, it takes time and effort to implement it in a vehicle. Further, even after the system is installed in a vehicle, there are problems such as a delay in determining whether to coast due to calculation processing for estimation.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to realize a structure that can be easily implemented in a vehicle and that can suppress delays in determining whether to perform coasting. It's about doing.

The vehicle control system of the present invention includes a clutch device, an actual torque detection means, and a control device.
The clutch device is provided on a drive force transmission path between a drive source and drive wheels of a vehicle.
The actual torque detection means detects the actual torque of a portion of the driving force transmission path located downstream of the connection/disconnection portion of the clutch device.
The control device uses the actual torque detected by the actual torque detection means to determine whether coasting of the vehicle is possible, and determines that coasting of the vehicle is possible. In this case, control is performed to switch the clutch device from a connected state to a disconnected state.

The vehicle control system of the present invention includes a vehicle speed sensor that detects the speed of the vehicle, and an accelerator opening sensor that detects the amount of operation of the accelerator pedal by the driver of the vehicle, and the control device is configured to control the speed of the vehicle. A configuration is adopted in which the determination as to whether coasting is possible is made by further utilizing the speed of the vehicle detected by the vehicle speed sensor and the operation amount of the accelerator pedal detected by the accelerator opening sensor. can do.

The vehicle control system of the present invention includes an accelerator opening sensor that detects an operation amount of an accelerator pedal by a driver of the vehicle, and the control device controls the operation of the accelerator pedal detected by the accelerator opening sensor. It is possible to adopt a configuration in which the required accelerator torque is estimated based on the amount and the required accelerator torque is further used to determine whether or not coasting of the vehicle is possible.

According to the vehicle control system of the present invention, it is possible to easily implement it in a vehicle, and it is also possible to suppress a delay in determining whether to perform coasting.

FIG. 1 is a block diagram showing main parts of a vehicle related to a first example of an embodiment of the present invention. FIG. 2 is a flowchart illustrating a procedure for determining whether coasting is to be executed or stopped by the ECU, according to the first example of the embodiment of the present invention.

[First example of embodiment]
A first example of the embodiment of the present invention will be described using FIGS. 1 and 2.
FIG. 1 shows a simplified part of a vehicle 1 equipped with a vehicle control system of this example. The vehicle 1 is an automatic clutch vehicle that automatically performs clutch control, and includes an engine 2, a manual transmission 3, a clutch device 4, a torque sensor 5 as an actual torque detection means, and an ECU (Electronic Control Unit) as a control device. ) 6, a differential 7, a drive shaft 8, a pair of drive wheels 9, and the like.

The rotation of the crankshaft 10 constituting the engine 2 is input to the input shaft 11 of the manual transmission 3 via the clutch device 4, and is transmitted from the output shaft 12 of the manual transmission 3 to the differential 7, drive shaft 8, etc. is transmitted to the drive wheels 9.

The engine 2 includes a plurality of cylinders, a fuel injection device, and a throttle valve. Based on control signals from the ECU 6, the fuel injection device injects an appropriate amount of fuel into each cylinder at an appropriate timing or stops fuel injection. The throttle valve adjusts the amount of air supplied to each cylinder based on a control signal from the ECU 6. The mixture of fuel and air supplied into each cylinder is ignited and combusted by a spark plug operated based on a control signal from the ECU 6. Then, the air-fuel mixture is combusted in each cylinder, causing the crankshaft 10 to rotate.

The manual transmission 3 has a plurality of gears with different speed ratios, and includes a transmission actuator (not shown). The transmission actuator is electrically connected to the shift lever 13 via the ECU 6, and changes the gear stage of the manual transmission 3 according to the operating position of the shift lever 13. The manual transmission 3 changes the rotational speed of the crankshaft 10 to a desired rotational speed according to the selected gear stage, and finally transmits the rotational speed to the pair of drive wheels 9.

The clutch device 4 includes a clutch 14, which is a connecting/disconnecting portion provided between the crankshaft 10 and the input shaft 11, and a hydraulic or electric clutch switching device 15. The clutch device 4 operates a clutch switching device 15 based on a control signal from the ECU 6 to switch between a connected and disconnected state of the clutch 14 (that is, a torque transmission state between the crankshaft 10 and the input shaft 11). ). Specifically, the clutch 14 is switched between a fully connected state (clutch engaged state), an incompletely connected state (half-clutched state), and a completely disconnected state (clutch disengaged state).

The torque sensor 5 is for detecting the actual torque (actual transmission torque) input to the input shaft 11 via the clutch device 4, and is used to transmit driving force between the engine 2 and the pair of drive wheels 9. It is arranged around the input shaft 11 located downstream of the clutch device 4 on the path. The torque sensor 5 has an annular shape as a whole, is disposed so as to surround the input shaft 11, and is supported by a part such as a housing that does not rotate during use, and its detection part is It is made to closely oppose the outer circumferential surface of the input shaft 11, which is the detected portion. In this example, the torque sensor 5 is a magnetostrictive torque sensor equipped with a plurality of coil layers constituting a bridge circuit. Measurement is performed using the inverse magnetostriction effect. For this reason, the input shaft 11, including the detected portion, is partially or entirely made of a material having magnetostrictive characteristics.

The ECU 6 controls the entire vehicle and includes a plurality of control units such as a clutch control unit, an engine control unit, a transmission control unit, and a brake control unit. In addition to a position sensor 16 for detecting the operation position of the shift lever 13 by the driver of the vehicle 1, the ECU 6 includes a torque sensor 5, and a torque sensor 5, which detects the operation amount (depression amount, accelerator opening amount) of the accelerator pedal 17 by the driver of the vehicle 1. ), a brake opening sensor 20 for detecting the operation amount (depression amount, brake opening) of the brake pedal 19 by the driver of the vehicle 1, and the speed of the vehicle 1 (vehicle speed). A vehicle speed sensor 21 for detecting the rotation speed of the engine 2, an engine rotation speed sensor 22 for detecting the rotation speed of the engine 2, and the like are connected.

In particular, in this example, a vehicle control system is configured by the clutch device 4, the torque sensor 5, the ECU 6, etc., and coasting control of the vehicle 1 is performed. For this purpose, the ECU 6 uses actual torque information detected by the torque sensor 5 to control the clutch device 4.

Specifically, when the vehicle 1 is not performing coasting, the ECU 6 determines whether coasting is to be performed if all conditions 1 to 4 below continue for a predetermined period of time (for example, 5 seconds). It is determined that it is possible. Then, the clutch device 4 is instructed to gently disengage the clutch 14 and start coasting.

Condition 1: The vehicle speed is greater than or equal to a predetermined value (for example, 30 km/h), and the variation in vehicle speed is within a predetermined range (for example, ±2 km/h).
Condition 2: The accelerator opening is within a predetermined range (for example, 3 to 5%).
Condition 3: The clutch 14 of the clutch device 4 is fully connected (completely connected), and the brake is not operating {that is, the brake opening is zero (brake OFF)}.
Condition 4: The required accelerator torque is smaller than the actual torque, or the actual torque is less than a predetermined value (for example, 100 Nm).

Note that the required accelerator torque is the required output torque of the engine 2 according to the amount of operation of the accelerator pedal 17 by the driver of the vehicle 1. Regarding condition 4, the required accelerator torque is estimated from the accelerator opening degree, and the actual torque is detected using the torque sensor 5. For this purpose, the ECU 6 stores a map prepared in advance for estimating the required accelerator torque from the accelerator opening degree.

In addition, when the vehicle 1 is coasting, the ECU 6 determines whether the following condition 6 is satisfied for a predetermined period of time (for example, 2 seconds), or when the following condition 5, condition 7, and condition 8 are satisfied. If at least one of the following is true, it is determined that coasting should be stopped. Then, the clutch device 4 is instructed to gently connect the clutch 14 and stop coasting.

Condition 5: The vehicle speed is below a predetermined value (for example, 20 km/h).
Condition 6: The accelerator opening is outside a predetermined range (for example, 8% or more or 0%), or the accelerator request torque is greater than or equal to a predetermined magnitude (for example, actual torque + 10 Nm).
Condition 7: A gear shift instruction has been issued.
Condition 8: The brake is operating {that is, the brake opening is not zero (brake ON)}.

The procedure for determining whether to perform or cancel coasting by the ECU 6 as described above will be explained based on the flowchart of FIG. 2.

In the first step S1, it is determined whether the vehicle 1 is coasting. When the determination in step S1 is no (that is, when the vehicle 1 is not coasting), the process advances to step S2.

In step S2, it is determined whether a part of condition 1 is satisfied (that is, whether the vehicle speed is greater than or equal to a predetermined value (for example, 30 km/h)). If the determination in step S2 is no, the process returns to step S1. On the other hand, if the determination in step S2 is yes, the process advances to step S3.

In step S3, it is determined whether condition 2 is satisfied (that is, whether the accelerator opening is within a predetermined range (for example, 3 to 5%)). If the determination in step S3 is no, the process returns to step S1. On the other hand, if the determination in step S3 is yes, the process advances to step S4.

In step S4, it is determined whether condition 3 is satisfied (that is, the clutch 14 of the clutch device 4 is in a fully connected state (completely connected), and the brake is not in operation (brake OFF). whether it is true or not. If the determination in step S4 is no, the process returns to step S1. On the other hand, if the determination in step S4 is yes, the process advances to step S5.

In step S5, it is determined whether condition 4 is satisfied (that is, whether the accelerator request torque is smaller than the actual torque, or whether the actual torque is less than or equal to a predetermined value (for example, 100 Nm). } is determined. If the determination in step S5 is no, the process returns to step S1. On the other hand, when the determination in step S5 is yes, the process advances to step S6.
Note that the order of steps S2 to S5 may be changed as appropriate.

In step S6, it is determined whether a state in which part of Condition 1 and all of Conditions 2 to 4 described above are satisfied continues (continuously elapses) for a predetermined period of time (for example, 5 seconds). If the determination in step S6 is no, the process returns to step S1. On the other hand, if the determination in step S6 is yes, the process advances to step S7.

In step S7, whether or not the remainder of condition 1 is satisfied during that time {that is, during the predetermined period of time (for example, 5 seconds) in step S6} {that is, the variation in vehicle speed is within a predetermined range (for example, ±2 km/h) } is determined. If the determination in step S7 is no, the process returns to step S1. On the other hand, if the determination in step S7 is yes, the process advances to step S8.

In step S8, it is determined that coasting can be performed, and the clutch device 4 is instructed to gently disengage the clutch 14 and start coasting. Then, the process returns to step S1.

On the other hand, when the determination in the first step S1 is yes (that is, when the vehicle 1 is coasting), the process proceeds to step S9.

In step S9, it is determined whether condition 5 is satisfied (that is, whether the vehicle speed is less than or equal to a predetermined value (for example, 20 km/h)). If the determination in step S9 is yes, the process advances to step S14. In step S14, it is determined that the coasting should be stopped, and the clutch device 4 is instructed to gently connect the clutch 14 to stop the coasting. Then, the process returns to step S1. On the other hand, if the determination in step S9 is no, the process advances to step S10.

In step S10, it is determined whether condition 7 is satisfied (that is, whether a shift instruction has been issued). If the determination in step S10 is yes, the process advances to step S14. In step S14, it is determined that the coasting should be stopped, and the clutch device 4 is instructed to gently connect the clutch 14 to stop the coasting. Then, the process returns to step S1. On the other hand, when the determination in step S10 is no, the process advances to step S11.

In step S11, it is determined whether condition 8 is satisfied {that is, whether the brake is operating (brake ON)}. If the determination in step S11 is yes, the process advances to step S14. In step S14, it is determined that the coasting should be stopped, and the clutch device 4 is instructed to gently connect the clutch 14 to stop the coasting. Then, the process returns to step S1. On the other hand, when the determination in step S11 is no, the process advances to step S12.
Note that the order of steps S9 to S11 may be changed as appropriate.

In step S12, it is determined whether condition 6 is satisfied (that is, whether the accelerator opening is outside a predetermined range (for example, 8% or more or 0%), or whether the accelerator request torque is within a predetermined magnitude (for example, Actual torque + 10 Nm) or more is determined. If the determination in step S12 is no, the process returns to step S1. On the other hand, when the determination in step S12 is YES, the process advances to step S13.

In step S13, it is determined whether the state satisfying condition 6 described above continues (continuously elapses) for a predetermined period of time (for example, 2 seconds). If the determination in step S13 is no, the process returns to step S1. On the other hand, if the determination in step S13 is yes, the process advances to step S14.

In step S14, it is determined that the coasting should be stopped, and the clutch device 4 is instructed to gently connect the clutch 14 to stop the coasting. Then, the process returns to step S1.

Note that the numerical values in the flowchart of FIG. 2 are just one example. The present invention can be implemented by changing these values as appropriate. That is, in the present invention, by appropriately changing these values, it is possible to freely determine the driving conditions under which the vehicle 1 performs coasting.

In any case, in this example, the ECU 6 suppresses fuel consumption by reducing the rotation of the engine 2 to idle rotation or stopping the engine 2 while the vehicle 1 is coasting. . In addition, when stopping the engine 2 at this time, the ECU 6 determines whether or not the engine 2 can be pushed forward before stopping coasting (that is, before connecting the clutch 14). However, if pushing is not possible, an engine 2 start request command is sent to an engine starting motor (not shown) to start the engine 2.

As explained above, in the vehicle control system of this example, the ECU 6 performs coasting control of the vehicle 1 using the torque input to the input shaft 11. In particular, in this example, the torque input to the input shaft 11 is not estimated from the vehicle speed or the accelerator opening, but is actually measured by the torque sensor 5. Therefore, troublesome work such as constructing logic and models for estimating the torque input to the input shaft 11, matching the model with actual measurements, and setting a safety factor to the estimated value is unnecessary. Therefore, the mounting on the vehicle 1 can be made easier. In addition, even after it is installed in the vehicle 1, calculation processing for estimating the torque input to the input shaft 11 is no longer necessary, so the delay in determining whether to perform or cancel coasting can be suppressed accordingly.

Further, when implementing the vehicle control system of this example, it is determined in step S5 of the flowchart shown in FIG. If a configuration is adopted in which it is determined in S12 whether or not the accelerator opening is outside a predetermined range (for example, 8% or more or 0%), there is no need to estimate the required accelerator torque. Therefore, in this case, it is not necessary to construct a logic or model for estimating the accelerator request torque, to match the model with actual measurements, and to set a safety factor to the estimated value. Therefore, the system can be more easily installed in the vehicle 1. Furthermore, even after the system is installed in the vehicle 1, calculation processing for estimating the accelerator request torque is no longer necessary, so that delays in determining whether to perform or cancel coasting can be further suppressed.

In addition, when carrying out the present invention, as a modification of the first example of the embodiment, the installation position of the torque sensor 5 on the driving force transmission path between the engine 2 and the pair of drive wheels 9 (actual The torque detection position) was changed, for example, to between the manual transmission 3 and the differential 7 (the specific position is not limited, but as an example, the chain line α in FIG. 1 around the output shaft 12). Adopt a changed configuration between the differential 7 and the drive wheels 9 (the specific position is not limited, but as an example, the chain line β in FIG. 1 near the pair of drive wheels 9). I can do it.

INDUSTRIAL APPLICABILITY The present invention can be applied to various types of vehicles in which a clutch device capable of switching the power transmission state is provided on a power transmission path between a drive source and drive wheels. Therefore, the present invention is applicable not only to vehicles equipped with a manual transmission but also to vehicles equipped with an automatic transmission. Further, the present invention can also be applied to a vehicle equipped with an electric motor instead of an engine as a drive source, or a vehicle equipped with both an engine and an electric motor as a drive source. Furthermore, in the case of a vehicle equipped with only an electric motor as a drive source, it is not necessary to include a transmission.
In a vehicle equipped with an electric motor as a drive source, power consumption can be reduced by stopping the electric motor during coasting.
In a vehicle equipped with an electric motor as a drive source, if the electric motor is to be stopped during coasting, the electric motor must be stopped before coasting is stopped (that is, before the clutch device is connected). start.
Moreover, when implementing the present invention, the installation position of the clutch device on the power transmission path between the drive source and the drive wheels is not particularly limited. Further, the installation position of the actual torque detection means on the power transmission path between the drive source and the drive wheels is not particularly limited as long as it is downstream of the connection/disconnection portion of the clutch device.
Further, the method of detecting torque by the actual torque detecting means is not limited. That is, the actual torque detecting means is not limited to the magnetostrictive type, and various types such as a phase difference type that detects a shift in torsional phase between two points can be adopted.

1 Vehicle 2 Engine 3 Manual transmission 4 Clutch device 5 Torque sensor 6 ECU
7 Differential 8 Drive shaft 9 Drive wheel 10 Crankshaft 11 Input shaft 12 Output shaft 13 Shift lever 14 Clutch 15 Clutch switching device 16 Position sensor 17 Accelerator pedal 18 Accelerator opening sensor 19 Brake pedal 20 Brake opening sensor 21 Vehicle speed sensor 22 Engine rotation speed sensor

Claims (2)

a clutch device provided on a drive power transmission path between a drive source and drive wheels of a vehicle;
actual torque detection means for detecting actual torque of a portion located downstream of the connecting/disconnecting portion of the clutch device on the driving force transmission path;
an accelerator opening sensor that detects the amount of operation of an accelerator pedal by the driver of the vehicle;
a control device that controls switching the clutch device from a connected state to a disconnected state when it is determined that coasting of the vehicle is possible;
Equipped with
The control device estimates an accelerator request torque based on the operation amount of the accelerator pedal detected by the accelerator opening degree sensor, and estimates the accelerator request torque from the actual torque detected by the actual torque detection means. determining that coasting of the vehicle is possible on one condition that the vehicle is also small;
Vehicle control system. The vehicle is equipped with a vehicle speed sensor that detects the speed of the vehicle;
The control device further sets the condition that the speed of the vehicle detected by the vehicle speed sensor is equal to or higher than a predetermined value, and that fluctuations in the speed of the vehicle are within a predetermined range. , determining that coasting of the vehicle is possible ;
The vehicle control system according to claim 1.

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