JP7800501B2 - vehicle - Google Patents

Description

This disclosure relates to vehicles.

Conventionally, for this type of vehicle, a system has been proposed that uses detection data from a crank angle sensor that detects the engine crank angle to determine whether or not to enable idling stop control (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2007-237961

In a vehicle equipped with a first control device that controls the engine and a second control device capable of communicating with the first control device, the first control device transmits a sensor-driven signal based on a sensor signal from a crank angle sensor that detects the engine crank angle to the second control device via a dedicated communication line, and the second control device determines whether to permit idling stop control using the engine speed based on the sensor-driven signal, the system prohibits idling stop control if an abnormality occurs in the dedicated communication line.

The primary purpose of the vehicle disclosed herein is to be able to determine whether or not to permit idling stop control even if an abnormality occurs in the dedicated communication line.

The vehicle disclosed herein employs the following measures to achieve the above-mentioned primary objective.

The vehicle of the present disclosure includes:
A vehicle including a first control device that controls an engine, and a second control device that is capable of communicating with the first control device and determines whether or not to permit idling stop control,
the first control device transmits a sensor-induced signal based on a sensor signal from a crank angle sensor for detecting a crank angle of the engine to the second control device via a dedicated communication line, and transmits a first rotation speed, which is the rotation speed of the engine based on the sensor signal, to the second control device via a shared communication line;
When the dedicated communication line is normal, the second control device determines whether or not to permit the idling stop control using a second rotation speed, which is the rotation speed of the engine based on the sensor-induced signal, and when the dedicated communication line is abnormal, determines whether or not to permit the idling stop control using the first rotation speed.
The gist of this is as follows.

The vehicle disclosed herein includes a first control device and a second control device. The first control device transmits a sensor-induced signal based on a sensor signal from a crank angle sensor that detects the engine crank angle to the second control device via a dedicated communication line, and transmits a first rotation speed, which is the engine rotation speed based on the sensor signal, to the second control device via a shared communication line. When the dedicated communication line is normal, the second control device determines whether to permit idling stop control using the second rotation speed, which is the engine rotation speed based on the sensor-induced signal, and when the dedicated communication line is abnormal, it determines whether to permit idling stop control using the first rotation speed. This makes it possible to determine whether to permit idling stop control even if an abnormality occurs in the dedicated communication line.

In the vehicle disclosed herein, the second control device may determine whether the dedicated communication line is normal by comparing the first rotation speed with the second rotation speed.

In the vehicle disclosed herein, the second control device may, when determining whether to permit idling stop control, shorten the determination time when the first rotation speed is used compared to the determination time when the second rotation speed is used.

The vehicle of the present disclosure may be equipped with a neutral start switch that is turned on when the operating position of the shift lever is a non-driving position and turned off when the operating position is a driving position, and the first control unit acquires the operating position of the shift lever as a shift position and transmits it to the second control unit via the shared communication line, and the second control unit receives an on/off signal indicating whether the neutral start switch is on or off via a second dedicated communication line, and during and/or after a stop determination of the engine due to the idling stop control, if the second dedicated communication line is normal, the second control unit uses the on/off signal to determine whether to request the implementation of brake holding control that applies braking force to the vehicle, and if the second dedicated communication line is abnormal, to determine whether to request the implementation of brake holding control.

In this case, the second control device may determine whether the second dedicated communication line is normal by comparing the on/off signal with the shift position.

1 is a schematic configuration diagram of a vehicle 10 according to the present disclosure. FIG. 2 is a control block diagram of the vehicle 10. 10 is a flowchart showing an example of a determination rotation speed setting routine. 10 is a flowchart showing an example of a brake holding control execution request determination routine.

Embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic diagram of a vehicle 10 of the present disclosure. As shown in FIG. 1, the vehicle 10 includes an engine 12, an auxiliary battery 18, and a power transmission device 20. The vehicle 10 may be a rear-wheel drive vehicle as shown, a front-wheel drive vehicle, or a four-wheel drive vehicle.

The engine 12 is configured as a multiple-cylinder internal combustion engine that outputs power using fuel such as gasoline or diesel, and the crankshaft of the engine 12 is connected to the power transmission device 20. A starter motor 14 for cranking the engine 12 is connected to the crankshaft of the engine 12.

The auxiliary battery 18 is a lead-acid battery with a rated voltage of 12V, 24V, or 48V. The auxiliary battery 18 is connected to the starter motor 14 via a neutral start switch 32 and a key/push switch 36, as well as via a start-stop electronic control unit (hereinafter referred to as "S&SECU") 48. The neutral start switch 32 turns on and off depending on the operating position of the shift lever. The operating positions of the shift lever include, for example, the parking position (P position), reverse position (R position), neutral position (N position), and forward position (D position). The neutral start switch 32 is on when the shift lever is in a non-driving position (P position or N position) and off when the shift lever is in a driving position (R position or D position). When the shift lever is shifted from a position other than P to P, the drive wheels DW are locked by a parking lock mechanism (not shown), and when the shift lever is shifted from P to a position other than P, the drive wheels DW are unlocked. Details of the S&SECU 48 will be described later.

The power transmission device 20 is configured to transmit power from the engine 12 to the left and right drive wheels (rear wheels) and includes a starting device 21, a mechanical oil pump 22, a transmission 23, a differential gear 24, and a hydraulic control device 25. The starting device 21 is a torque converter with torque amplification function and includes a lock-up clutch 21c and a damper mechanism 21d. The mechanical oil pump 22 is driven by power from the engine 12. The transmission 23 is configured as a multi-speed (stepped) transmission with 4 to 10 speeds and includes an input shaft, an output shaft, multiple planetary gears, and multiple hydraulically driven clutches and brakes. The input shaft is connected to the crankshaft of the engine 12 via the starting device 21, and the output shaft is connected to the left and right drive wheels DW via the differential gear 24 and drive shaft DS. The transmission 23 changes the speed of the power transmitted from the engine 12 to the input shaft via the starting device 21 in multiple stages and outputs the power to the output shaft. Instead of a multi-speed transmission, the transmission 23 may be a continuously variable transmission (CVT) or a dual clutch transmission. The hydraulic control device 25 has a valve body with multiple oil passages, multiple regulator valves, and multiple linear solenoid valves. The hydraulic control device 25 regulates the hydraulic pressure of the hydraulic oil from the mechanical oil pump 22 and supplies it to the starting device 21 and the multiple clutches and brakes of the transmission 23.

Figure 2 is a control block diagram of vehicle 10. As shown in Figure 2, vehicle 10 includes an engine electronic control unit (hereinafter referred to as "engine ECU") 40, a transmission electronic control unit (hereinafter referred to as "TMECU") 42, a brake electronic control unit (hereinafter referred to as "brake ECU") 44, and an S&SECU 48. The engine ECU 40, TMECU 42, brake ECU 44, and S&SECU 48 can communicate via a shared communication line (CAN bus) CB. The engine ECU 40 and S&SECU 48 can also communicate via a dedicated communication line (local bus) LB1. Note that communication delays between the engine ECU 40 and S&SECU 48 via the dedicated communication line LB1 are significantly reduced compared to communication between the two ECUs via the shared communication line CB.

The engine ECU 40 includes a microcomputer with a CPU, ROM, RAM, flash memory, and input/output interface. The engine ECU 40 receives signals related to the engine 12 status from various sensors, such as the first pulse signal Sp1 from the crank angle sensor 13. The crank angle sensor 13 is attached to the crankshaft of the engine 12 and includes a timing rotor with 34 protrusions (excluding the two consecutive protrusions) on its outer periphery, which are located every 10 degrees. The timing rotor also includes an electromagnetic pickup that outputs the first pulse signal Sp1 each time the protrusion passes through the rotor as the timing rotor rotates. The engine ECU 40 also receives the accelerator pedal position (Acc), which indicates the amount of accelerator pedal depression, from the accelerator pedal position sensor 49. The engine ECU 40 controls the operation of the engine 12 (e.g., intake air volume control, fuel injection control, ignition control, etc.). The engine ECU 40 calculates the crank angle θcr of the crankshaft of the engine 12 and calculates the engine 12 rotation speed as a first rotation speed Ne1 based on the first pulse signal Sp1 from the crank angle sensor 13. The engine ECU 40 transmits a second pulse signal Sp2 (e.g., the same signal as the first pulse signal Sp1), which is a sensor-induced signal based on the first pulse signal Sp1, to the S&SECU 48 via a dedicated communication line LB1. The engine ECU 40 transmits the first rotation speed Ne1 and accelerator opening Acc of the engine 12 to the S&SECU 48 via a shared communication line CB.

The TMECU 42, like the engine ECU 40, is equipped with a microcomputer. The shift lever operating position is input to the TMECU 42 from the shift position sensor 34 as the shift position SP. The TMECU 42 controls the hydraulic control device 25 to regulate the hydraulic pressure from the mechanical oil pump 22 and supply it to the starting device 21 and multiple clutches and brakes of the transmission 23. The TMECU 42 transmits the shift position SP to the S&SECU 48 via the shared communication line CB.

The brake ECU 44, like the engine ECU 40, is equipped with a microcomputer. The brake ECU 44 receives inputs of the brake pedal position BP, which represents the amount of brake pedal depression, from the brake pedal position sensor 50, and the vehicle speed V from the vehicle speed sensor 51. The brake ECU 44 controls the brake actuator 30 of the hydraulic brake system to apply braking force to the vehicle (each wheel, including the drive wheels DW), based on the amount of brake pedal depression. In addition, in response to a request from another ECU (e.g., the S&SECU 48), the brake ECU 44 controls the brake actuator 30 to apply braking force to the vehicle, regardless of the driver's brake pedal depression. The brake ECU 44 transmits the brake pedal position BP and vehicle speed V to the S&SECU 48.

The S&SECU 48 includes a microcomputer similar to the engine ECU 40. The S&SECU 48 receives the second pulse signal Sp2 from the engine ECU 40 via a dedicated communication line LB1, and receives an on/off signal NSW indicating whether the neutral start switch 32 is on or off via a dedicated communication line LB2. The S&SECU 48 receives the first engine speed Ne1 and accelerator opening Acc of the engine 12 from the engine ECU 40 via a shared communication line CB, the shift position SP from the TMECU 42 via a shared communication line CB, and the brake pedal position BP and vehicle speed V from the brake ECU 44 via a shared communication line CB. The S&SECU 48 calculates the engine speed as the second engine speed Ne2 based on the second pulse signal Sp2. The S&SECU 48 controls the starter motor 14.

In the vehicle 10 of this embodiment configured as described above, when the neutral start switch 32 is turned on (the shift lever is in the non-driving position) and the key/push switch 36 is turned on, the starter motor 14 cranks the engine 12, and as the engine 12 speed increases, the engine ECU 42 begins operating control of the engine 12, starting the engine 12.

In addition, in the vehicle 10 of this embodiment, the S&SECU 48 executes idling stop control, stopping the engine 12 when a stop condition is met while the engine 12 is operating, and starting the engine 12 when a start condition is met. Examples of stop conditions include the shift position SP being in the D position, the accelerator being off (accelerator opening Acc is 0), the brake being on (brake pedal position BP is a positive value), the vehicle speed V being equal to or less than a threshold value Vref, and the engine 12 rotation speed, which is a determination rotation speed Nej, being equal to or less than a threshold value Neref. The determination rotation speed Nej is set by a determination rotation speed setting routine, which will be described later. Examples of starting conditions include when the shift position SP is in D and the brake is released (brake pedal position BP is 0), when the shift position SP is shifted from D to N or R, or when the shift position SP is shifted from D to P and then the brake is on (brake pedal position BP is a positive value) and the shift position SP is shifted to a position other than P. When a stop condition is met while the engine 12 is running, the S&SECU 48 stops the engine 12 by causing the engine ECU 40 to stop control of the engine 12. When a start condition is met, the S&SECU 48 starts the engine 12 by causing the starter motor 14 to crank the engine 12 and causing the engine ECU 42 to start control of the engine 12.

Next, the operation of the vehicle 10 of this embodiment, particularly the process for setting the determination rotation speed Nej, will be described. Figure 3 is a flowchart showing an example of a determination rotation speed setting routine that is repeatedly executed by the S&SECU 48. This routine is executed repeatedly.

When the engine speed setting routine of FIG. 3 is executed, the S&S ECU 48 determines whether the dedicated communication line LB1 is normal (step S100). This determination can be made by determining whether the difference ΔNe between the second engine speed Ne2 of the engine 12 based on the second pulse signal Sp2 received from the engine ECU 40 via the dedicated communication line LB1 and the first engine speed Ne of the engine 12 received from the engine ECU 40 via the shared communication line CB is equal to or less than a threshold value ΔNeref. For example, if the second pulse signal Sp2 is interrupted due to a break in the dedicated communication line LB1 and the second engine speed Ne2 is zero, but the first engine speed Ne1 is a certain positive value, the dedicated communication line LB1 is determined to be abnormal.

If step S100 determines that the dedicated communication line LB1 is normal, the second rotation speed Ne2 of the engine 12 is set to the determination rotation speed Nej (step S110), and the routine ends. As described above, communication via the dedicated communication line LB1 significantly reduces communication delays compared to communication via the shared communication line CB. Therefore, by setting the second rotation speed Ne2 of the engine 12 to the determination rotation speed Nej, the determination rotation speed Nej can be set to a more appropriate value (closer to the actual rotation speed) than when the first rotation speed Ne1 of the engine 12 is set to the determination rotation speed Nej. As a result, it is possible to more appropriately determine whether the stop condition is met, i.e., whether idling stop control is permitted or not. Then, when the stop condition is met and the engine 12 is to be stopped, the determination rotation speed Nej is used to determine whether the engine 12 has stopped. The engine 12 stop determination is used to adjust the drive timing of the starter motor 14, etc.

If it is determined in step S100 that the dedicated communication line LB1 is abnormal, the first rotation speed Ne1 of the engine 12 is set to the determination rotation speed Nej (step S120), and the routine ends. This makes it possible to determine whether or not to permit idling stop control even if an abnormality such as a break occurs in the dedicated communication line LB1.

In the idling stop control, when determining whether the determination rotation speed Nej, one of the stop conditions, is equal to or less than the threshold value Neref, or when determining whether the engine 12 has stopped, it is preferable to set the determination time Tj1 when the first rotation speed Ne1 of the engine 12 is set to the determination rotation speed Nej (when the dedicated communication line LB1 is abnormal) to be shorter than the determination time Tj2 when the second rotation speed Ne2 of the engine 12 is set to the determination rotation speed Nej (when the dedicated communication line LB1 is normal). As described above, communication delays are sufficiently reduced in communication via the dedicated communication line LB1 compared to communication via the shared communication line CB. Therefore, if the determination times Tj1 and Tj2 are set to be the same, the required determination time from transmission of the first engine speed Ne1 or the second pulse signal Sp2 of the engine 12 from the engine ECU 40 to completion of the determination may be somewhat longer when the first engine speed Ne1 is set to the determination speed Nej than when the second engine speed Ne2 is set to the determination speed Nej. By making the determination time Tj1 shorter than the determination time Tj2, the required determination time can be prevented from being longer when the first engine speed Ne1 is set to the determination speed Nej than when the second engine speed Ne2 is set to the determination speed Nej. Note that the determination times Tj1 and Tj2 may also be set to be the same.

Next, the operation during and/or after the engine 12 stop determination during idling stop control will be described. During and/or after the engine 12 stop determination, the S&SECU 48 repeatedly executes the brake maintenance control implementation request determination routine shown in Figure 4 until the engine 12 has been started or until the request to implement brake maintenance control, which applies braking force to the vehicle regardless of whether the brake pedal is depressed (whether the brake pedal position BP is a positive value or zero), is canceled.

When the brake hold control implementation request determination routine of FIG. 4 is executed, the S&SECU 48 determines whether the dedicated communication line LB2 is normal (step S200). This determination can be made by checking whether the on/off signal NSW has been received from the neutral start switch 32, or by comparing the on/off signal NSW with the shift position SP from the shift position sensor 34. For example, if the on/off signal NSW is on and the shift position SP is in D, it is determined that the dedicated communication line LB2 is abnormal.

If step S200 determines that the dedicated communication line LB2 is normal, the ECU 48 determines that the on/off signal NSW should be used (step S210) and determines whether the on/off signal NSW is on (step S220). If step S200 determines that the on/off signal NSW is off, the ECU 48 transmits a request to the brake ECU 44 to implement brake hold control (step S250), terminating this routine. Upon receiving the request, the brake ECU 44 executes brake hold control. As described above, when the brake is released with the shift position SP in the D position or when the shift position SP is shifted from the D position to the R position, the start condition is met, and the engine 12 is started. Once the engine 12 has been started (for example, when the S&SECU 48 determines that the engine has been started using the determination rotation speed Nej), the S&SECU 48 transmits a cancellation of the request to implement brake hold control to the brake ECU 44. When the brake ECU 44 receives a cancellation of the request to implement brake hold control, it basically cancels the implementation of brake hold control and applies a braking force to the vehicle according to the amount of depression of the brake pedal. However, even if the request to implement brake hold control is canceled, there are cases in which brake hold control continues due to other factors.

If it is determined in step S220 that the on/off signal NSW is on, a cancellation of the request to implement brake hold control is sent to the brake ECU 44 (step S260), and this routine ends.

If it is determined in step S200 that there is an abnormality in the dedicated communication line LB2, it is determined that the shift position SP should be used instead of the on/off signal NSW (step S230), and the shift position SP is checked (step S240). If it is determined that the shift position SP is the D position or the R position, a request is made to implement brake hold control (step S250), and the routine ends. On the other hand, if it is determined that the shift position SP is the P position or the N position, the request to implement brake hold control is canceled (step S260), and the routine ends. This makes it possible to determine whether to request the implementation of brake hold control even if there is an abnormality, such as a break in the dedicated communication line LB2.

In the vehicle 10 of this embodiment described above, the engine ECU 40 (first control device) transmits a second pulse signal Sp2 (sensor-induced signal) based on a first pulse signal Sp1 (sensor signal) from the crank angle sensor 13 to the S&SECU 48 (second control device) via the dedicated communication line LB1, and transmits a first rotation speed Ne1 of the engine 12 based on the first pulse signal Sp1 to the S&SECU 48 via the shared communication line CB. When the dedicated communication line LB1 is normal, the S&SECU 48 determines whether to permit idling stop control using the second rotation speed Ne2 of the engine 12 based on the second pulse signal Sp2. When the dedicated communication line LB1 is abnormal, the S&SECU 48 determines whether to permit idling stop control using the first rotation speed Ne1 of the engine 12. This makes it possible to determine whether to permit idling stop control even if an abnormality occurs in the dedicated communication line LB1.

Furthermore, in the vehicle 10 of this embodiment, when determining whether the determination rotation speed Nej, one of the stop conditions for idling stop control, is equal to or less than the threshold value Neref, and when determining whether the engine 12 has stopped, the determination time Tj1 when the first rotation speed Ne1 of the engine 12 is used (when the dedicated communication line LB1 is abnormal) is set to be shorter than the determination time Tj2 when the second rotation speed Ne2 of the engine 12 is used (when the dedicated communication line LB1 is normal). This prevents the determination required time from transmission of the first rotation speed Ne1 or the second pulse signal Sp2 of the engine 12 from the engine ECU 40 to completion of the determination from being longer when the first rotation speed Ne1 is used than when the second rotation speed Ne2 is used.

Furthermore, in the vehicle 10 of this embodiment, the TMECU 42 acquires the shift position SP and transmits it to the S&SECU 48 via the shared communication line CB. The S&SECU 48 also receives an on/off signal NSW, indicating whether the neutral start switch 32 is on or off, via the dedicated communication line LB2. Furthermore, during and/or after the engine 12 stop determination during idling control, if the dedicated communication line LB2 is normal, the on/off signal NSW is used to determine whether to request the implementation of brake hold control. If the dedicated communication line LB2 is abnormal, the shift position SP is used to determine whether to request the implementation of brake hold control. This makes it possible to determine whether to request the implementation of brake hold control even if an abnormality occurs in the dedicated communication line LB2.

In the above-described embodiment, the vehicle 10 is equipped with the engine ECU 40, the TMECU 42, the brake ECU 44, and the S&SECU 48. However, at least two of the engine ECU 40, the TMECU, and the brake ECU 44 may be configured as an integrated unit. Furthermore, the TMECU 42 and the S&SECU 48 may be configured as an integrated unit, or the brake ECU 44 and the S&SECU 48 may be configured as an integrated unit.

The following explains the correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section. In the embodiment, the engine ECU 40 corresponds to the "first control device," the S&SECU 48 corresponds to the "second control device," the crank angle sensor 13 corresponds to the "crank angle sensor," the dedicated communication line LB1 corresponds to the "dedicated communication line," and the shared communication line CB corresponds to the "shared communication line." Furthermore, the neutral start switch 32 corresponds to the "neutral start switch," the TMECU 42 corresponds to the "first control device," and the dedicated communication line LB2 corresponds to the "second dedicated communication line."

The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, as the embodiments are examples used to specifically explain the form for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

The above describes embodiments for implementing the present disclosure, but the present disclosure is in no way limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the spirit of the present disclosure.

This disclosure can be used in the vehicle manufacturing industry, etc.

10 vehicle, 12 engine, 13 crank angle sensor, 14 starter motor, 18 auxiliary battery, 20 power transmission device, 21 starting device, 21c lock-up clutch, 21d damper mechanism, 22 mechanical oil pump, 23 transmission, 25 hydraulic control device, 30 brake actuator, 32 neutral start switch, 34 shift position sensor, 36 key/push switch, 40 engine ECU, 42 TM ECU, 44 brake ECU, 48 S&SECU, 49 accelerator pedal position sensor, 50 brake pedal position sensor, 51 vehicle speed sensor, CB common communication line, LB1, LB2 dedicated communication lines.

Claims (4)

A vehicle including a first control device that controls an engine, and a second control device that is capable of communicating with the first control device and determines whether or not to permit idling stop control,
the first control device transmits a sensor-induced signal based on a sensor signal from a crank angle sensor for detecting a crank angle of the engine to the second control device via a dedicated communication line, and transmits a first rotation speed, which is the rotation speed of the engine based on the sensor signal, to the second control device via a shared communication line;
the second control device, when the dedicated communication line is normal, determines whether to permit the idling stop control using a second rotation speed that is a rotation speed of the engine based on the sensor-induced signal, and, when the dedicated communication line is abnormal, determines whether to permit the idling stop control using the first rotation speed ;
the vehicle includes a neutral start switch that is turned on when an operating position of a shift lever is a non-driving position and that is turned off when the operating position of the shift lever is a driving position, and a third control device that acquires the operating position of the shift lever as a shift position and transmits the acquired shift position to the second control device via the shared communication line;
the second control device receives an on/off signal indicating whether the neutral start switch is on or off via a second dedicated communication line;
During and/or after the engine stop determination due to the idling stop control, when the second dedicated communication line is normal, the second control device determines whether or not to issue a request for brake holding control to apply braking force to the vehicle, using the on/off signal, and when the second dedicated communication line is abnormal, determines whether or not to issue a request for brake holding control, using the shift position.
vehicle. 2. The vehicle according to claim 1,
the second control device determines whether the dedicated communication line is normal by comparing the first rotation speed with the second rotation speed;
vehicle. 3. The vehicle according to claim 1 or 2,
the second control device, in determining whether or not to permit the idling stop control, sets a determination time when the first rotation speed is used shorter than a determination time when the second rotation speed is used.
vehicle. 2. The vehicle according to claim 1 ,
the second control device determines whether the second dedicated communication line is normal by comparing the on/off signal with the shift position;
vehicle.