JP2012236557A - Control device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a hybrid vehicle that can estimate the engine torque of the engine that drives an engine driving shaft by using the torque of the motor that drives the motor driving shaft.SOLUTION: The control device of the hybrid vehicle includes: an engine information detection means (steps S5-S8 and steps S10-S13) that detects the engine state information that has the proportional relation to the engine torque, and is displayed by the proportion to the maximum engine torque; a conversion factor calculating means (steps S14-S19) that calculates the conversion factor which converts the engine state information into the engine torque based on the variation of the motor torque when the motor torque is changed by the prescribed amount in a state where the total driving force of the vehicle is maintained constant and the variation of the engine state information according to the change in the motor torque; and an engine torque calculating means (steps S20-S23) that calculates the engine torque based on the conversion factor and the engine state information.

Description

  The present invention relates to a control device for a hybrid vehicle that estimates an engine torque of an engine that rotationally drives an engine drive shaft using a motor torque of a motor that rotationally drives a motor drive shaft.

2. Description of the Related Art Conventionally, a connected vehicle is known in which a plurality of vehicles including an engine-driven vehicle and a motor-driven vehicle are connected, and the driving force is shared by the motor-driven vehicle to improve the fuel efficiency of the engine-driven vehicle (for example, Patent Document 1). reference).
In this coupled vehicle, in order to control both the engine-driven vehicle and the motor-driven vehicle in an integrated manner, the respective control devices are connected to the integrated controller. Here, engine state information indicating the operating state of the engine is input to the integrated controller. In this coupled vehicle, the engine-driven vehicle and the motor-driven vehicle can be separated and replaced with different vehicles as appropriate.

On the other hand, in a hybrid vehicle having an engine and a motor as drive sources, a hybrid vehicle control device that uses a motor torque command value as an actual engine torque is known (see, for example, Patent Document 2).
In this hybrid vehicle control device, first, the amount of torque change of the engine when the engine torque command value is changed is estimated. Next, the motor torque is controlled in a direction that cancels the estimated engine torque variation while maintaining the output rotational speed from the power train. The motor torque command value at this time is set as the actual engine torque.

JP 2008-12938 A JP 2000-130203 A

However, in a conventional coupled vehicle, the engine state information is proportional to the engine output torque and is displayed as a ratio (percentage) to the maximum output torque according to the engine speed. That is, the engine state information has different change characteristics for each maximum output torque of the engine that changes according to the engine speed.
Here, the maximum output torque of the engine according to the engine speed has different characteristics for each engine. Therefore, every time the engine-driven vehicle is replaced, the change characteristics of the engine state information also differ, and the engine output torque cannot be grasped from the engine state information, and the motor-driven vehicle is appropriately controlled to improve fuel efficiency. It was difficult.

  On the other hand, in the conventional hybrid vehicle control device, the amount of engine torque change when the engine torque command value is changed is estimated. Here, the estimation of the engine torque change amount is performed based on the relationship between the engine torque command value and the actual engine torque that have been experimentally obtained in advance. That is, in the conventional hybrid vehicle control device, it is necessary to grasp in advance the relationship between the engine torque command value and the actual engine torque.

  On the other hand, in a coupled vehicle in which an engine-driven vehicle and a motor-driven vehicle are connected, the engine-driven vehicle can be replaced. For this reason, it is difficult to grasp in advance the relationship between the engine torque command value and the actual engine torque. That is, when the torque characteristics of the engine cannot be grasped, the engine torque change amount cannot be estimated as in the conventional hybrid vehicle control device, and the motor torque command value cannot be set to the actual engine torque.

  Therefore, the present invention has been made paying attention to the above problem, and uses the torque of the motor that rotationally drives the motor drive shaft even when the torque characteristics of the engine that rotationally drives the engine drive shaft are unknown. It is an object of the present invention to provide a hybrid vehicle control device that can estimate engine torque.

In order to achieve the above object, in the hybrid vehicle control device of the present invention, an engine drive shaft that is rotationally driven by an engine, a motor drive shaft that is rotationally driven by a motor, and an engine torque estimating means that estimates the engine torque of the engine; Motor assist control means for controlling the engine torque by driving the motor to rotate and assisting the driving force of the engine drive shaft, the engine torque estimating means comprising engine information detecting means and driving force holding means Means, motor control means, conversion coefficient calculation means, and engine torque calculation means.
The engine information detection means detects engine state information that is proportional to the engine torque and that is displayed as a percentage of the maximum engine torque.
The driving force holding means holds a total driving force that is a sum of the driving force of the engine driving shaft and the driving force of the motor driving shaft constant.
The motor control means changes the motor torque by a predetermined amount while keeping the total driving force constant.
The conversion coefficient calculation unit calculates a conversion coefficient for converting the engine state information into the engine torque based on the change amount of the motor torque and the change amount of the engine state information accompanying the change of the motor torque.
The engine torque calculation means calculates the engine torque based on the conversion coefficient and the engine state information.

Therefore, in the hybrid vehicle control device of the present invention, the engine torque is calculated from the conversion coefficient calculated based on the change amount of the motor torque and the change amount of the engine state information and the engine state information.
That is, the amount of change in the motor torque output from the motor by changing the motor torque by a predetermined amount while keeping the total driving force, which is the sum of the driving force of the engine driving shaft and the driving force of the motor driving shaft, constant. Is regarded as the amount of change in engine torque. On the other hand, the engine state information has a proportional relationship with the conversion coefficient as a proportional constant with respect to the engine torque.
Thus, a conversion coefficient is obtained from the change amount of the motor torque and the change amount of the engine information, and the engine torque is calculated from the engine state information using the conversion coefficient.
As a result, even if the torque characteristics of the engine that rotationally drives the engine drive shaft are unknown, the engine torque can be estimated using the torque of the motor that rotationally drives the motor drive shaft.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external view showing a full trailer truck to which a hybrid vehicle control device according to a first embodiment is applied. 1 is an overall system diagram illustrating a tractor of a full trailer truck according to a first embodiment. 1 is an overall system diagram illustrating a trailer of a full trailer truck according to Embodiment 1. FIG. FIG. 2 is a control block diagram of a full trailer truck to which the hybrid vehicle control device of the first embodiment is applied. It is explanatory drawing which shows the relationship between an engine torque instruction | command and an actual engine torque, (a) shows when an engine speed is (alpha), (b) shows when an engine speed is (beta). 3 is a flowchart illustrating a flow of engine torque estimation processing executed by the integrated controller of the first embodiment. It is explanatory drawing which shows an example of an engine speed area table. It is explanatory drawing which shows an example of the conversion coefficient table produced in an engine torque estimation process. It is a flowchart which shows the flow of the engine efficiency estimation process performed in the integrated controller of Example 1. FIG. It is explanatory drawing which shows an example of an engine torque area | region table. It is explanatory drawing which shows an example of the engine efficiency table created in an engine efficiency estimation process. It is explanatory drawing which shows an example of the optimal fuel consumption line map created in an engine efficiency estimation process. 4 is a flowchart illustrating a flow of a motor assist process executed by the integrated controller according to the first embodiment. It is an example of the motor assist torque setting map used in a motor assist process. It is the figure which showed the characteristic of the motor torque maximum value with respect to motor rotation speed. 4 is a time chart showing characteristics of an auto cruise signal, an engine torque command, and an actual motor torque in an engine torque estimation scene in the full trailer truck of the first embodiment. (a) is a characteristic diagram showing the relationship between the accelerator opening and the driving force in the trailer truck of Example 1, and (b) is a characteristic diagram showing the motor assist force. It is a time chart which shows each characteristic of an auto cruise signal, an engine torque command, and an actual motor torque in an engine torque estimation scene in a control device for a hybrid vehicle of another example.

  Hereinafter, a mode for realizing a control device for a hybrid vehicle of the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
FIG. 1 is an external view showing a full trailer truck to which a control device for a hybrid vehicle of Example 1 is applied. A full trailer truck (hybrid vehicle) 1 shown in FIG. 1 includes a tractor 2 and a trailer 3.

  The tractor 2 is a self-propelled tow vehicle, and here is a full tractor having a total vehicle weight of 25 t and a total length of 12 m. The tractor 2 includes a driver's cab 2a and a cargo compartment 2b for loading cargo.

  The trailer 3 is a non-self-propelled towed vehicle towed by the tractor 2, and here is a full trailer having a total vehicle weight of 19 t and a total length of 7 m. The trailer 3 has a luggage compartment 3b for loading cargo.

Next, the drive system of the tractor 2 will be described.
FIG. 2 is an overall system diagram illustrating the tractor of the full trailer truck according to the first embodiment.

  As shown in FIG. 2, the drive system of the tractor 2 in the first embodiment includes an engine 201, a clutch 202, a transmission 203, a propeller shaft (engine drive shaft) 204, and first and second differentials 205a and 205b. First left and right drive shafts 206a and 206b, second left and right drive shafts 207a and 207b, first left and right rear wheels 208a and 208b (drive wheels), second left and right rear wheels 209a and 209b (drive wheels), and brakes Unit 210. Reference numerals 214 and 214 denote left and right front wheels.

  Here, the engine 201 is a diesel engine having a maximum output of 380 kW. Based on an engine torque command or the like from the engine controller 221, an engine start control, an engine stop control, a throttle valve opening control, a fuel cut control, etc. Is done. The engine 201 is connected to a starter motor 201a, and the engine 201 is started by driving the starter motor 201a. The starter motor 201a is driven by power supplied from a 24V on-vehicle battery 201b.

  The clutch 202 is operated based on a clutch control command from the engine controller 221 and connects and disconnects the force flow between the engine 201 and the transmission 203.

  The transmission 203 is a stepped transmission that automatically switches the shift speed based on a shift control command from the AT controller 222. A propeller shaft 204 is connected to the transmission output shaft of the transmission 203.

  The propeller shaft 204 is connected to the first left and right rear wheels 208a and 208b via the first differential 205a and the first left and right drive shafts 206a and 206b, and the second differential 205b and the second left and right drive shafts 207a and 207b are connected to each other. The second left and right rear wheels 209a and 209b are connected to each other.

  The brake unit 210 includes a plurality of brake devices 211,... And a retarder device 212.

  The brake device 211 includes a brake disk 211a fixed so as not to rotate with respect to the first and second left and right drive shafts 206a, 206b, 207a, and 207b, and a brake disposed so as to sandwich the brake disk 211a. A cylinder 211b. The brake device 211 restricts the rotation of the brake disc 211a with the brake cylinder 211b based on a brake control command from the brake controller 223, and individually controls the first and second left and right rear wheels 208a, 208b, 209a, and 209b. To brake.

  The retarder device 212 is driven by ON-controlling a retarder switch (not shown) disposed in the cab 2a, and controls and brakes the rotation of the propeller shaft 204 using, for example, fluid resistance.

Further, a display device 213 is mounted in the cab 2a of the tractor 2.
The display device 213 displays the driving state of the tractor 2 and is connected to an integrated controller 315 (to be described later) via a CAN communication line 231, and is mounted on the driving instruction information output from the integrated controller 315 and the trailer 3. Information on various devices is displayed as appropriate.

Next, the control system of the tractor 2 will be described.
As shown in FIG. 2, the control system of the tractor 2 according to the first embodiment includes an engine controller 221, an AT controller 222, and a brake controller 223. The engine controller 221, the AT controller 222, and the brake controller 223 are connected via a CAN communication line 220 that can exchange information with each other.

The engine controller 221 inputs necessary information from the engine speed sensor 224, the auto cruise switch 225, and other sensors. Then, for example, an engine torque command or a fuel consumption control command for controlling the engine operating point (Ne, Te) so as to obtain a driving force corresponding to the driver's required driving force obtained from the accelerator opening, It outputs to the valve actuator and outputs a clutch control command to the clutch 202.
Here, the auto-cruise switch 225 is disposed in the driver's cab 2a and is set to the auto-cruise mode by being turned on. The “auto cruise mode” is a traveling mode in which the total driving force in the full trailer truck 1 that combines the driving force of the tractor 2 and the driving force of the trailer 3 is kept constant and a predetermined vehicle speed is maintained.

  The AT controller 222 inputs necessary information from an accelerator opening sensor 226, a vehicle speed sensor 227, and other sensors. Then, when traveling with the D range selected, a shift control for obtaining an optimum shift stage by searching for an optimum shift stage based on a position where an operating point determined by the accelerator opening and the vehicle speed exists on a shift map (not shown). The command is output to the hydraulic control valve unit of the transmission 203.

  The brake controller 223 inputs necessary information from a wheel speed sensor 228 for detecting each wheel speed of the four wheels, a brake stroke sensor 229, and other sensors. Then, for example, a brake control command for obtaining a braking force corresponding to the required braking force obtained from the brake stroke is output to the brake device 211. When a retarder switch (not shown) is ON-controlled, a retarder control command for driving the retarder device 212 is output.

  Further, the engine controller 221 is connected to an integrated controller 315 described later via a CAN communication line 230. The engine controller 221 then sends the engine torque command information, accelerator opening information, engine speed information, vehicle speed information, fuel injection amount information, auto cruise information, and other necessary information to the integrated controller 315 via the CAN communication line 230. Is output.

Next, the drive system of the trailer 3 will be described.
FIG. 3 is an overall system diagram illustrating the trailer of the full trailer truck according to the first embodiment.

  As shown in FIG. 3, the drive system of the trailer 3 in the first embodiment includes a motor generator (motor) 301, a propeller shaft (motor drive shaft) 302, a differential 303, left and right drive shafts 304a and 304b, and left and right rears. Wheels 305a and 305b (drive wheels) and a brake unit (not shown) are included. Reference numerals 306 and 306 denote left and right front wheels.

  Here, the motor generator 301 is a synchronous motor in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and has a rated output of 134 kW and a maximum output of 300 kW. The motor generator 301 is controlled by applying a three-phase alternating current generated by the inverter 312. The motor generator 301 is driven to rotate by receiving power supplied from the battery 313, and can operate as an electric motor that drives the left and right rear wheels 305a and 305b (powering), or the rotor can be operated as the left and right rear wheels 305a and 305b. When rotating energy is received from the battery, it functions as a generator that generates electromotive force at both ends of the stator coil, and can also charge the battery 313 (regeneration). A propeller shaft 302 is connected to the motor output shaft of the motor generator 301.

  The propeller shaft 302 is connected to left and right rear wheels 305a and 305b via a differential 303 and left and right drive shafts 304a and 304b.

Next, the control system of the trailer 3 will be described.
As shown in FIG. 3, the control system of the trailer 3 in the first embodiment includes a motor controller 311, an inverter 312, a battery 313, a battery controller 314, an integrated controller 315, and a cooling system (not shown). Configured. The motor controller 311, the battery controller 314, the cooling system, and the integrated controller 315 are connected via a CAN communication line 310 that can exchange information with each other.

  The motor controller 311 includes a resolver 316 for detecting the rotor rotational position of the motor generator 301, a motor rotational speed sensor 317, a target motor torque or target motor rotational speed from the integrated controller 315, and information from other sensors. Enter. Then, a motor torque command or a motor rotation speed command for controlling the motor operating point (Nm, Tm) of motor generator 301 is output to inverter 312.

  The battery controller 314 monitors the battery SOC indicating the charging capacity of the battery 313, the battery voltage, the battery current, the battery temperature, and the like, and supplies the battery information to the integrated controller 315 via the CAN communication line 310. To do. Here, the battery 313 is a lithium ion battery having a maximum charging capacity of 36.3 kW.

  The cooling system includes a cooling fan for the motor generator 301, a cooling fan for the battery 313, and the like. In this cooling system, on the basis of a cooling command from the integrated controller 315, each cooling fan or the like is ON / OFF controlled to adjust the temperature of the motor generator 301 and the battery 313.

The integrated controller 315 is responsible for managing the energy consumption of the entire vehicle and for running the vehicle with the highest efficiency. That is, the integrated controller 315 performs at least engine torque estimation processing, engine efficiency estimation processing, and motor assist control processing.
Here, the engine torque estimation process is a process for estimating the engine torque output from the engine 201 of the tractor 2. The engine efficiency estimation process is a process for estimating the engine torque when the engine efficiency is maximized for each rotation speed of the engine 201. The motor assist control process is a process for driving and controlling the motor generator 301 so that the output torque of the engine 201 becomes the engine torque (optimum fuel efficiency torque) when the engine efficiency becomes maximum.

  Therefore, as shown in FIG. 4, the motor speed information, motor temperature information, inverter temperature information, motor torque information, and other necessary information are input to the integrated controller 315 from the motor controller 311 via the CAN communication line 310. Battery SOC information, battery voltage information, battery current information, battery temperature information, and other necessary information are input from the battery controller 314. Further, this integrated controller 315 requires engine torque command information, accelerator opening information, engine speed information, vehicle speed information, fuel injection amount information, auto cruise information, and other necessary information from the engine controller 221 via the CAN communication line 230. Information is entered. Further, information from a dolly rotation angle sensor (not shown) and information from an air brake pressure sensor (not shown) are input to the integrated controller 315.

  The integrated controller 315 outputs the target motor torque or the target motor rotation speed to the motor controller 311 via the CAN communication line 310, outputs a cooling command to a cooling system (not shown), and issues a brake command to a brake unit (not shown). Output. Further, the integrated controller 315 displays the shift position information of the transmission 203, the clutch ON / OFF information, the retarder ON / OFF information, the battery SOC information of the battery 313, and the trailer side failure information via the CAN communication line 231. Output to.

Here, the CAN communication line 230 and the CAN communication line 231 are connected to the integrated controller 315 via the gateway controller 232. The gateway controller 232 converts the output signal from the engine controller 221 of the tractor 2 so that it can be read by the integrated controller 315, and enables the display device 213 to display the output signal from the integrated controller 315. And a conversion program for converting to
Therefore, the engine torque command output from the engine controller 221 has a proportional relationship with the actual engine torque (actual engine torque) as shown in FIG. 5A, and the maximum engine torque at that time. It is displayed as a percentage (percentage). Here, the maximum engine torque varies depending on the engine speed. For this reason, as shown in FIG. 5 (b), when the engine speed is different, the maximum engine torque varies, and the change characteristic (proportional constant) of the engine torque command also differs. It should be noted that the integrated engine 315 cannot grasp the maximum engine torque that fluctuates according to the engine speed, that is, the engine torque characteristic. For this reason, the integrated controller 315 cannot grasp the change characteristic of the engine torque command that varies depending on the engine speed. The “engine torque command” corresponds to engine state information indicating the operating state of the engine 201.

  The integrated controller 315 further includes a backup memory (storage means) 315a for storing necessary operators such as conversion coefficients described later. The backup memory 315a is driven by being supplied with power from an in-vehicle battery 201b mounted on the tractor 2. That is, the backup memory 315a is electrically connected / disconnected to the in-vehicle battery 201b in accordance with the dividing / connecting operation of the tractor 2 and the trailer 3 and is ON / OFF controlled. The backup memory 315a is turned off when the tractor 2 and the trailer 3 are disconnected, and the stored contents are reset. When the tractor 2 and the trailer 3 are connected, the power is turned on and set to a preset initial value.

  The tractor 2 and the trailer 3 are connected in tandem by one connector 4 </ b> A provided at the rear portion of the tractor 2 and the other connector 4 </ b> B provided at the front portion of the trailer 3. The pair of couplers 4A and 4B have a well-known configuration and will not be described in detail here. The pair of connectors 4A and 4B are disconnected as necessary, and the tractor 2 or trailer 3 can be replaced.

  Further, at the rear part of the tractor 2 and the front part of the trailer 3, communication connectors 5A and 5B for connecting the mutual communication systems, hydraulic connectors 6A and 6B for connecting the respective hydraulic systems, and the respective pneumatic systems are provided. Pneumatic connectors 7A and 7B to be connected are respectively provided. The communication connectors 5A and 5B, the hydraulic connectors 6A and 6B, and the pneumatic connectors 7A and 7B each have a known configuration that can be connected and disconnected, and detailed description thereof is omitted here. Each connector 5A, 5B, 6A, 6B, 7A, 7B is disconnected with the pair of connectors 4A, 4B as necessary. Furthermore, here, the electrical connectors for electrically connecting the in-vehicle battery 201b and the backup memory 315a to the communication connectors 5A and 5B are included. That is, the power supply of the backup memory 315a is ON / OFF controlled in accordance with the connection / disconnection of the communication connectors 5A and 5B.

  FIG. 6 is a flowchart illustrating a flow of engine torque estimation processing executed by the integrated controller of the first embodiment. Hereinafter, each step of FIG. 6 will be described. This engine torque estimation process corresponds to engine torque estimation means for estimating the engine torque of the engine 201.

  In step S1, it is determined whether or not the backup memory 315a has been reset. If YES (memory reset), the process proceeds to step S2, and if NO (memory non-reset), the process proceeds to step S20.

In step S2, following the determination that the backup memory is reset in step S1, it is determined whether or not the auto cruise switch 225 has been turned ON. If YES (auto cruise ON), the process proceeds to step S3. If NO (auto cruise OFF), step S2 is repeated.
Here, ON / OFF determination of the auto cruise switch 225 is performed based on auto cruise information input from the engine controller 221 via the CAN communication line 230.

  In step S3, following the determination that auto-cruise is ON in step S2, the current rotational speed of the engine 201 is read, and the process proceeds to step S4. This engine speed is input from the engine controller 221 via the CAN communication line 230.

In step S4, following the reading of the engine speed in step S3, a rotation speed range of the read engine speed is set, and the process proceeds to step S5.
Here, in the setting of the engine speed range, it is determined whether the read engine speed corresponds to the engine speed range in the preset engine speed range table (see FIG. 7), and the corresponding area is determined. This is done by setting the current engine speed range. The “engine speed range” refers to a rotational speed width having a specific width with respect to a predetermined engine speed.

  In step S5, following the setting of the engine speed range in step S4, the current engine torque command is read, and the process proceeds to step S6. This engine torque command is input from the engine controller 221 via the CAN communication line 230.

In step S6, following the reading of the engine torque command in step S5, it is determined whether or not the amount of change in the engine torque command is within a predetermined range with respect to the read engine torque command. If YES (change amount is within the predetermined range), the process proceeds to step S7. If NO (change amount is outside the predetermined range), the process returns to step S2.
Here, the “predetermined range” is a variation range necessary for the engine torque command to be considered constant, and is set in advance.

In step S7, following the determination that the engine torque command change amount in step S6 is within a predetermined range, it is determined whether or not a predetermined time has elapsed since the reading of the engine torque command in step S5. If YES (predetermined time has elapsed), the process proceeds to step S8. If NO (predetermined time has not elapsed), the process returns to step S2.
Here, the “predetermined time” is a time necessary for the engine torque command to be considered constant, and is set in advance.

  In step S8, following the determination that the predetermined time has elapsed in step S7, assuming that the engine torque command is constant, the engine torque command read in step S5 is determined as the “engine torque command before motor driving”, and the process proceeds to step S9. move on.

In step S9, following the determination of the engine torque command before motor driving in step S8, the motor generator 301 of the trailer 3 is driven with a predetermined motor torque, and the process proceeds to step S10.
Here, the “predetermined motor torque” may be a positive torque when the motor generator 301 is operated as an electric motor and assists the driving force of the engine 201, or the motor generator 301 is operated as a generator and the battery is operated. It may be a negative torque when charging 313.

In step S10, following the driving of the motor generator 301 in step S9, the current engine torque command is read, and the process proceeds to step S11. This engine torque command is input from the engine controller 221 via the CAN communication line 230.
Here, the engine torque command is small when the engine driving force is assisted by the motor generator 301 and is large when the battery is charged by the motor generator 301.

In step S11, following the reading of the engine torque command in step S10, it is determined whether or not the change amount of the engine torque command is within a predetermined range with respect to the read engine torque command. If YES (within the predetermined amount of change), the process proceeds to step S12. If NO (outside the predetermined amount of change), the process returns to step S10.
Here, the “predetermined range” is a variation range necessary for the engine torque command to be considered constant as in step S6, and is set in advance.

In step S12, following the determination that the engine torque command change amount in step S11 is within a predetermined range, it is determined whether or not a predetermined time has elapsed since the reading of the engine torque command in step S10. If YES (predetermined time has elapsed), the process proceeds to step S13. If NO (predetermined time has not elapsed), the process returns to step S10.
Here, the “predetermined time” is a time necessary for the engine torque command to be considered constant as in step S7, and is set in advance.

  In step S13, following the determination that the predetermined time has elapsed in step S12, assuming that the engine torque command is constant, the engine torque command read in step S10 is determined as the “motor torque command after motor driving”, and the process proceeds to step S14. move on.

In step S14, following the determination of the engine torque command after motor driving in step S13, a conversion coefficient for converting the engine torque command into an estimated value of the engine torque is calculated, and the process proceeds to step S15.
Here, the calculation of the conversion coefficient is performed based on the motor torque when the motor generator 301 is driven in step S <b> 9 and the change amount of the engine torque command accompanying the driving of the motor generator 301. In step S14, the “change amount of the engine torque command” is obtained from the difference between the pre-motor engine torque command value determined in step S8 and the post-motor engine torque command determined in step S13.
That is, the total driving force in the full trailer truck 1 that combines the driving force of the tractor 2 and the driving force of the trailer 3 is constant (does not change) before and after the motor generator 301 is driven because the auto cruise switch 225 is turned on. It is considered. As a result, when the tractor driving force before driving the motor generator 301 is EFb [kN], the tractor driving force after driving the motor generator 301 is EFa [kN], and the motive generator driving force is MFc [kN], (1) is established.
EFa = EFb + MFc (1)
If the conversion coefficient for converting the engine torque command into the estimated value of the engine torque is “Kc [Nm /%]”, the engine torque command is proportional to the engine torque with the conversion coefficient as a proportional constant. have.
Furthermore, the following formulas (2) to (4) are established from a general relational expression of driving force and torque.
EFb = (ETb × Kc × ie × ηte) / (1000 × rde) (2)
MFc = (MTc × im × ηtm) / (1000 × rdm) (3)
EFa = (ETa × Kc × ie × ηte) / (1000 × rde) (4)
Here, “ETb” is an engine torque command [%] before motor driving, “MTc” is a driving torque [Nm] of motor generator 301, and “EFa” is an engine torque command [%] after motor driving. , “Ie” is the total reduction ratio in the engine 201, “im” is the total reduction ratio in the motor generator 301, “ηte” is the engine power transmission efficiency, and “ηtm” is the motor generator power transmission efficiency. , “Rde” is the effective tire radius [m] of the engine drive wheels (first and second left and right rear wheels 208a, 208b, 209a, 209b), and “rdm” is the motor drive wheels (left and right rear wheels 305a, 305b). The effective tire radius is [m].
On the other hand, the following equation (5) is established from the above equation (1). That is, the motor generator driving force is regarded as a change amount of the engine driving force.
MFc = EFa−EFb (5)
Therefore, the following equation (6) is established based on the above equations (2), (4), and (5).
MFc = {(ETa × Kc × ie × ηte) / (1000 × rde)} − {(ETb × Kc × ie × ηte) / (1000 × rde)} (6)
When this equation (6) is arranged, the following equation (7) is obtained.
MFc = {(ETa−ETb) × Kc × ie × ηte)} / (1000 × rde) (7)
Therefore, the following expression (8) for calculating the conversion coefficient is derived from the above expression (7), and the conversion coefficient for converting the engine torque command into the estimated value of the engine torque is calculated based on the expression (8). Is done.
Kc = [MFc × (1000 × rde) / (ie × ηte)] / (ETa−ETb) (8)

  In step S15, following the calculation of the conversion coefficient in step S14, the calculated conversion coefficient is stored in the backup memory 315a in association with the engine speed range set in step S4, and the process proceeds to step S16.

In step S16, following the storage of the conversion coefficient in step S15, it is determined whether or not the conversion coefficient has been calculated a predetermined number of times in the same engine speed range. If YES (calculated a predetermined number of times), the process proceeds to step S17. If NO (predetermined number of times has not been calculated), the process returns to step S2.
Here, whether or not the conversion coefficient has been calculated a predetermined number of times is determined based on whether or not a predetermined number of conversion coefficients have been stored in the backup memory 315a in the same engine speed range.

In step S17, following the determination of calculating the predetermined number of times in step S16, an average value of conversion coefficients calculated for the predetermined number of times (hereinafter referred to as “conversion coefficient value”) is calculated, and the process proceeds to step S18.
Here, the conversion coefficient value is calculated using either a simple averaging method (arithmetic averaging) or a weighting method. The “simple averaging method” is a method of obtaining the conversion coefficient value by dividing the total sum of the calculated conversion coefficients by the total number of calculations. The “weighting method” is a method for obtaining a conversion coefficient value in consideration of the weight for the calculated conversion coefficient, and is obtained by the following equation (9).
Kca = d * Kcn + (1-d) * Kca (9)
Here, “Kca” is a conversion coefficient value stored in the backup memory 315a, “Kcn” is a newly calculated conversion coefficient, and “d” is a weighting coefficient (0 <d <1).

  In step S18, following the calculation of the conversion coefficient value in step S17, the calculated conversion coefficient value is stored in the backup memory 315a in association with the engine speed range set in step S16, and the process proceeds to step S19.

In step S19, following the storage of the conversion coefficient value in step S18, it is determined whether or not the conversion coefficient value is stored in all of the preset engine speed ranges. If YES (stores all), the process proceeds to step S20 because the conversion coefficient table has been created. If NO (does not store all), the process returns to step S16 because the conversion coefficient table has not been created.
Here, the “conversion coefficient table” is a table in which conversion coefficient values are set for each engine speed range as shown in FIG.

  In step S20, following the determination of backup non-reset in step S1 or the determination of conversion coefficient table generation in step S19, the current rotational speed of the engine 201 is read, and the process proceeds to step S21. This engine speed is input from the engine controller 221 via the CAN communication line 230.

  In step S21, following the reading of the engine speed in step S20, the conversion coefficient value in the engine speed range corresponding to the read engine speed is read based on the “conversion coefficient table”, and the process proceeds to step S22.

  In step S22, following the reading of the conversion coefficient value in step S21, the current engine torque command is read, and the process proceeds to step S23. This engine torque command is input from the engine controller 221 via the CAN communication line 230.

In step S23, following the reading of the engine torque command in step S22, the current engine torque is calculated based on the engine torque command and the conversion coefficient value read in step S21, and the process proceeds to the end.
Here, calculation of the engine torque (ET _ij ) is performed by the following equation (10).
ET _ij = ETc × Kcai (10)
At this time, “ETc” is the current engine torque command read in step S22, and “Kcai” is the conversion coefficient value corresponding to the current engine speed read in step S21.

  In the engine torque estimation process, step S2 is a driving force for keeping the total driving force, which is the sum of the driving force of the engine driving shaft (propeller shaft 204) and the driving force of the motor driving shaft (propeller shaft 302), constant. It corresponds to the holding means. Further, Step S5 to Step S8 and Step S10 to Step S13 are proportional to the engine torque, and engine information for detecting engine state information (engine torque command) displayed as a ratio to the maximum engine torque. It corresponds to detection means. Step S9 corresponds to motor control means for changing the motor torque by a predetermined amount while keeping the total driving force constant. Steps S14 to S19 are conversion coefficient calculation means for calculating a conversion coefficient for converting engine state information into engine torque based on the amount of change in motor torque and the amount of change in engine state information accompanying the change in motor torque. It corresponds to. Steps S20 to S23 correspond to engine torque calculating means for calculating the engine torque based on the conversion coefficient and the engine state information.

  FIG. 9 is a flowchart illustrating the flow of the engine efficiency estimation process executed by the integrated controller according to the first embodiment. Hereinafter, each step of FIG. 9 will be described. This engine efficiency estimation process is executed after the “conversion coefficient table” is created by the engine torque estimation process described above.

  In step S30, the current rotational speed of the engine 201 is read, and the process proceeds to step S31. This engine speed is input from the engine controller 221 via the CAN communication line 230.

  In step S31, following the reading of the engine speed in step S30, the conversion coefficient value in the engine speed range corresponding to the read engine speed is read based on the “conversion coefficient table” and proceeds to step S32.

  In step S32, following the reading of the conversion coefficient value in step S31, the current engine torque command is read, and the process proceeds to step S33. This engine torque command is input from the engine controller 221 via the CAN communication line 230.

  In step S33, following the reading of the engine torque command in step S32, the current engine torque is calculated based on the engine torque command and the conversion coefficient value read in step S31, and the process proceeds to step S34. Here, the calculation of the engine torque is performed based on the above equation (10).

In step S34, following the calculation of the engine torque in step S33, the calculated torque region of the engine torque is set, and the process proceeds to step S35.
Here, in setting the engine torque region, it is determined whether the calculated engine torque corresponds to an engine torque region in a preset engine torque region table (see FIG. 10), and the corresponding region is determined as the current engine torque. This is done by making it an area. The “engine torque region” is a torque width obtained by giving a specific width to a predetermined engine torque.

  In step S35, following the setting of the engine torque region in step S34, the current fuel injection amount in the engine 201 is read, and the process proceeds to step S36. This fuel injection amount is input from the engine controller 221 via the CAN communication line 230.

In step S36, following the reading of the engine fuel injection amount in step S35, the efficiency of the engine 201 is determined based on the engine fuel injection amount, the engine speed read in step S30, and the engine torque calculated in step S33. And proceeds to step S37.
Here, the calculation of the engine efficiency (ηe _ij ) is performed by the following equation (11).
ηe _ij = IC _ij / (ET _ij × Ne) (11)
“IC _ij ” is the current engine fuel injection amount read in step S35, “Ne” is the current engine speed read in step S30, and “ET _ij ” is the engine torque calculated in step S33. It is.

  In step S37, following the calculation of the engine efficiency in step S36, the calculated engine efficiency is backed up in association with the engine speed range corresponding to the engine speed read in step S30 and the engine torque range set in step S34. The data is stored in the memory 315a, and the process proceeds to step S38.

In step S38, following the storing of the engine efficiency in step S37, it is determined whether or not the engine efficiency has been calculated a predetermined number of times in the same engine speed range and engine torque range. If YES (calculated the predetermined number of times), the process proceeds to step S39. If NO (predetermined number of times has not been calculated), the process returns to step S30.
Here, whether or not the engine efficiency has been calculated a predetermined number of times is determined based on whether or not a predetermined number of engine efficiencies have been stored in the backup memory 315a in the same engine speed range and engine torque range.

In step S39, following the determination of calculating the predetermined number of times in step S38, an average value of engine efficiency calculated for the predetermined number of times (hereinafter referred to as “engine efficiency value”) is calculated, and the process proceeds to step S40.
Here, the engine efficiency value is calculated using a weighting method. This “weighting method” is a method for obtaining an engine efficiency value in consideration of a weight for the calculated engine efficiency, and is obtained by the following equation (12).
ηe _ij a = f × ηe _ij n + (1−f) × ηe _ij a (12)
Here, “ηe _ij a” is an engine efficiency value stored in the backup memory 315a, “ηe _ij n” is a newly calculated engine efficiency, and “f” is a weighting coefficient (0 <f <1). is there.

  In step S40, following the calculation of the engine efficiency value in step S39, the calculated engine efficiency value is stored in the backup memory 315a in association with the engine speed range and the engine torque region set in step S38, and the process proceeds to step S41. .

In step S41, following the storage of the engine efficiency value in step S40, it is determined whether or not the engine efficiency value is stored in all of the engine speed range and the engine torque range set in advance. If YES (store all), the process proceeds to step S42 because the engine efficiency table has been created. If NO (do not store all), the process returns to step S38 because the engine efficiency table has not been created.
Here, the “engine efficiency table” is a matrix table in which engine efficiency values are set for each engine speed region and engine torque region, as shown in FIG.

In step S42, following the determination of creating the engine efficiency table in step S41, based on the engine efficiency table, an engine torque region in which the engine efficiency value is maximized for each engine speed region (hereinafter referred to as optimum fuel efficiency torque). ), The selected optimum fuel efficiency torque and the engine speed range are associated with each other and stored in the backup memory 315a, and the process proceeds to the end.
That is, in this step S42, the characteristic indicating the optimum fuel consumption line of the engine 201 as shown in FIG. 12 is selected by selecting the optimum fuel consumption torque that is the engine torque region in which the engine efficiency value is maximized for each engine speed range. Create a diagram (hereinafter referred to as “optimum fuel consumption line map”).

  In the engine efficiency estimation process, step S30 corresponds to an engine speed detecting means for detecting the speed of the engine 201. Step S35 corresponds to fuel injection amount detection means for detecting the fuel injection amount of the engine 201. Steps S36 to S41 correspond to engine efficiency calculation means for calculating the engine efficiency according to the engine torque and the engine speed based on the engine torque, the fuel injection amount, and the engine speed. Step S42 corresponds to optimum fuel consumption torque estimating means for estimating the optimum fuel consumption torque that is the engine torque that maximizes the engine efficiency for each engine speed.

  FIG. 13 is a flowchart illustrating the flow of the motor assist control process executed by the integrated controller of the first embodiment. Hereinafter, each step of FIG. 13 will be described. This motor assist control process is executed after creating the “optimum fuel consumption line map” by the engine efficiency estimation process described above. In the motor assist control process shown in FIG. 13, when the engine torque becomes larger than the optimum fuel consumption torque, the motor (motor generator 301) is driven to rotate to drive the engine drive shaft (propeller shaft 204). It corresponds to a motor assist control means for assisting.

  In step S50, the current rotational speed of the engine 201 is read, and the process proceeds to step S51. This engine speed is input from the engine controller 221 via the CAN communication line 230.

  In step S51, following the reading of the engine speed in step S50, the optimum fuel consumption torque at the read engine speed is read based on the “optimum fuel consumption line map” and the engine speed range corresponding to the read engine speed is obtained. The conversion coefficient value at is read based on the “conversion coefficient table”, and the process proceeds to step S52.

  In step S52, following the reading of the optimum fuel consumption torque and conversion coefficient value in step S51, the current engine torque command is read, and the process proceeds to step S53. This engine torque command is input from the engine controller 221 via the CAN communication line 230.

  In step S53, following the reading of the engine torque command in step S52, the current engine torque is calculated based on the engine torque command and the conversion coefficient value read in step S51, and the process proceeds to step S54. Here, the calculation of the engine torque is performed by the above-described equation (10).

  In step S54, following the calculation of the engine torque in step S53, it is determined whether or not the current engine torque calculated in step S53 is larger than the optimum fuel consumption torque read in step S51. If YES (optimum fuel consumption torque> current engine torque), the process proceeds to step S55. If NO (optimum fuel consumption torque≤current engine torque), the process proceeds to step S56.

In step S55, following the determination of “optimum fuel consumption torque> current engine torque” in step S54, the motor assist torque set based on the accelerator opening in the tractor 2 and the total vehicle weight of the tractor 2 and trailer 3 is established. Is output to the motor controller 311 and the process proceeds to step S57.
Here, the “motor assist torque” includes accelerator opening information input from the engine controller 221 via the CAN communication line 230, weight information of the tractor 2, weight information of the trailer 3 detected by a weight detection sensor, and the like. It is set based on the accelerator opening shown in FIG. 14 and the assist torque setting map set in advance according to the total vehicle weight.
The “motor assist torque” increases as the accelerator opening increases, and increases as the total vehicle weight increases. Further, the “motor assist torque” has an upper limit value that is a motor torque maximum value (instantaneous maximum torque) set in advance according to the rotation speed of the motor generator 301. As shown in FIG. 15, the motor torque maximum value corresponding to the motor rotational speed has a characteristic of decreasing as the motor rotational speed increases.

  In step S56, following the determination of “optimum fuel consumption torque ≦ current engine torque” in step S54, the motor assist is not executed, and the process proceeds to step S57. That is, in this step S56, the motor generator 301 is not driven.

In step S57, it is determined whether or not a downshift has been performed in the transmission 203 of the tractor 2 following the execution of the motor assist in step S55 or the non-execution of motor assist in step S56. If YES (shift down execution), the process proceeds to return. If NO (shift down non-execution), the process returns to step S55.
Here, the downshift is executed when the required driving force increases even if the motor assist torque set in step S55 reaches the upper limit value. This shift-down execution determination is made based on shift information input from the engine controller 221 via the CAN communication line 230.

Next, the operation will be described.
First, the “technical problem in the motor assist control” according to the present invention will be described, and subsequently, the operation in the hybrid vehicle control device of the first embodiment will be described as “engine torque estimation operation”, “engine efficiency estimation operation”, “ The description will be divided into “motor assist operation”.

[Technical issues in motor assist control]
2. Description of the Related Art Conventionally, in a connected vehicle in which a towed vehicle is an engine-driven vehicle and a towed vehicle is a motor-driven vehicle, a connected vehicle that assists driving the engine-driven vehicle with the output torque of the motor-driven vehicle is known. In this coupled vehicle, the tow vehicle and the towed vehicle can be appropriately separated, and the tow vehicle can be replaced with another engine-driven vehicle.

  In such a connected vehicle, the control devices of each other are connected to the integrated controller in order to control both vehicles in an integrated manner. At this time, engine state information indicating the operating state of the engine in the engine-driven vehicle is input to the integrated controller. This engine state information is, for example, an engine torque command output from the engine controller, and is proportional to the output torque from the engine and is displayed as a percentage (percentage) with respect to the maximum output torque according to the engine speed. The

  On the other hand, the maximum output torque of the engine corresponding to the engine speed has different characteristics for each engine. However, the engine maximum output characteristic, that is, the engine torque characteristic, cannot be grasped by the integrated controller. That is, in a coupled vehicle, the engine-driven vehicle and the motor-driven vehicle can be separated and replaced with different vehicles as appropriate, and therefore the integrated controller cannot grasp the torque characteristics of the engine of the engine-driven vehicle.

  Furthermore, although the change characteristic of the engine state information varies from engine to engine, the integrated controller cannot grasp the torque characteristic of the engine. Therefore, the change characteristic of the engine state information cannot be grasped by the integrated controller. For this reason, it is difficult to estimate the engine torque from the engine state information. As a result, it is difficult to control the output torque of the engine-driven vehicle and the output torque of the motor-driven vehicle in a coordinated manner, and the energy efficiency of the entire connected vehicle cannot be improved.

  In recent years, in Europe and other countries, there are an increasing number of modified trucks that change the wheelbase and cargo bed of commercially available front-engine / front-drive trucks that use the front axle as the engine drive shaft and the rear axle as free. If the rear axle of such a modified vehicle is modified so that it can be driven by a motor, an effect equivalent to that of a connected vehicle that assists the driving of the engine driven vehicle of the towed vehicle by the output torque of the motor driven vehicle of the towed vehicle can be obtained. . In other words, the appearance of a modified car with a rear axle electrified can be considered.

  Even in such a modified vehicle, it is necessary to determine the motor assist amount and the regenerative amount according to the engine torque, but the actual engine torque cannot be grasped, and the improvement in energy efficiency cannot be expected. Therefore, it is necessary to estimate the engine torque even if the torque characteristics of the engine are unknown.

[Engine torque estimation effect]
FIG. 16 is a time chart showing characteristics of an auto cruise signal, an engine torque command, and an actual motor torque in an engine torque estimation scene in the full trailer truck of the first embodiment.

  In the full trailer truck 1 of the first embodiment, in order to estimate the output torque from the engine 201 of the tractor 2, when the vehicle is in an auto-cruise traveling state and the engine torque command is considered to be substantially constant, the motor generator 301 is used. Drive. Then, the amount of change in the engine torque command at this time is regarded as the output torque of the motor generator 301, and a conversion coefficient for converting the engine torque command into the engine torque is obtained based on the amount of change in the engine torque command. Since the engine torque command has different change characteristics depending on the engine speed, it is necessary to obtain a conversion coefficient for each engine speed. And if a conversion coefficient is calculated | required, an engine torque can be estimated by integrating | accumulating this conversion coefficient to an engine torque command.

  That is, at time t1 shown in FIG. 16, when the auto-cruise switch is ON-controlled and the auto-cruise signal is “ON”, the total driving force that combines the driving force of the tractor 2 and the driving force of the trailer 3 is held constant. The As a result, in the flowchart shown in FIG. 6, the process proceeds from step S1, step S2, step S3, step S4, and step S5 to set an engine speed range corresponding to the current engine speed (engine speed). Read the current engine torque command. Here, the engine torque command is ETb.

  Then, at a time t2, a change amount of the engine torque command is within a certain range (here, ± C%) with respect to the read engine torque command (ETb), and a predetermined time (here, Δt (= time t2) -When time t1) has elapsed, the process proceeds from step S6 to step S7 to step S8 in the flowchart shown in Fig. 6 to determine the engine torque command before motor driving, that is, the engine torque before the motor generator 301 is driven is stable. The engine torque command when it can be regarded as having been determined is the “engine torque command before motor driving”, and here “ETb”.

  If the engine torque command before motor driving is determined, the process proceeds to step S9 in the flowchart shown in FIG. 6 to drive the motor generator 301 with a predetermined motor torque. Here, regenerative control for charging the battery 313 by operating the motor generator 301 as a generator is performed, and the motor torque is controlled to be −Mct.

  On the other hand, a braking force acts on the full trailer track 1 by the regeneration control of the motor generator 301. Here, since the auto cruise signal is ON, the engine torque command increases so as to keep the total driving force of the tractor 2 and the trailer 3 constant.

  When the motor torque becomes -Mct at time t3, the process proceeds to step S10 in the flowchart shown in FIG. 6, and the current engine torque command is read. Here, the engine torque command is ETa. At time t4, if the change amount of the engine torque command is within a certain range (± C% in this case) with respect to the read engine torque command (ETa), the time count in this state is counted. Start. At a time t5, if a predetermined time (here, Δt (= time t4−time t5) elapses in a state where the variation amount of the engine torque command is within a certain range, step S11 → step S12 → step in the flowchart shown in FIG. The process proceeds to S13 to determine the engine torque command after driving the motor, that is, the engine torque command when the engine torque after driving the motor generator 301 can be regarded as stable is referred to as “engine torque command after motor driving”. Let's say “ETa”.

  When the engine torque command before and after driving motor generator 301 is determined, the process proceeds to step S14 in the flowchart shown in FIG. 6, and the engine torque command is converted into the engine torque based on these engine torque commands and the above equation (8). A conversion coefficient is calculated.

  Then, in the flowchart shown in FIG. 6, the process proceeds from step S15 to step S16, step S17, step S18, and step S19 to create a conversion coefficient table in which conversion coefficients are set for each engine speed range. That is, the calculated conversion coefficient is stored in association with the engine speed range, and if the conversion coefficient is calculated a predetermined number of times in the same engine speed range, the average conversion coefficient value is obtained, and the engine speed range The conversion coefficient values are stored in association with each other. For the conversion coefficient value, either a simple averaging method or a weighting method is selected.

  Once the conversion coefficient table is created, the conversion coefficient is not calculated again until the power source of the backup memory 315a is controlled to be turned on / off in accordance with the connection / disconnection of the communication connectors 5A and 5B. The engine torque is estimated using the measured value. That is, in the flowchart shown in FIG. 6, the process proceeds from step S20 to step S21 to step S22 to step S23. To estimate the actual engine torque.

  Thus, as shown in Expression (5), the motor driving force when the motor generator 301 is driven is regarded as the amount of change in the engine driving force. On the other hand, as shown in equations (2) and (4), it is assumed that the engine driving force can be calculated from a conversion coefficient for converting engine state information into engine torque and an engine torque command.

  And even if it is a case where the torque characteristic of the engine 201 is unknown, an engine torque can be calculated | required from the torque command from which a change characteristic changes according to an engine maximum output by calculating | requiring this conversion coefficient. As a result, the actual engine torque output from the engine 201 can be accurately grasped, and the respective output torques in the tractor 2 and the trailer 3 can be controlled in cooperation.

In the hybrid vehicle control apparatus according to the first embodiment, the engine torque command change amount is a value before the motor torque is changed and the motor torque pre-motor engine torque command which is a value when the engine torque command is stable. This is obtained from the difference between the motor torque after the motor driving and the post-motor engine torque command, which is a value when the engine torque command is stable.
Therefore, an error in the engine torque command with respect to the actual engine torque is suppressed, and the engine torque calculation accuracy can be improved.

  In addition, when the engine torque command change amount is within a predetermined range for a predetermined time, the engine torque command is stabilized, so that the stable state of the engine torque command can be easily and accurately determined. .

Further, in the hybrid vehicle control apparatus of the first embodiment, a conversion coefficient is calculated a predetermined number of times in the same engine speed range, and a conversion coefficient value that is an average value of the plurality of conversion coefficients is obtained. Then, the engine torque is calculated based on the conversion coefficient value and the engine torque command.
Thus, by calculating | requiring the average value of a conversion coefficient, the calculation precision of a conversion coefficient can be raised and the improvement of the calculation precision of an engine torque can be aimed at.

In the hybrid vehicle control apparatus of the first embodiment, the backup memory 315a for storing the conversion coefficient is reset when the tractor 2 and the trailer 3 are disconnected, and when the tractor 2 and the trailer 3 are connected, the backup memory 315a is set to a predetermined initial value. Is set.
For this reason, the replacement of the tractor 2 can be reliably detected, and the conversion coefficient can be calculated every time the engine 201 is different.

[Engine efficiency estimation effect]
In the hybrid vehicle control apparatus according to the first embodiment, the engine torque obtained based on the engine torque command and the conversion coefficient table input via the CAN communication line 230 and the engine 201 input via the CAN communication line 230 are used. The efficiency (engine efficiency) of the engine 201 of the tractor 2 is estimated from the fuel injection amount.

  Here, in order to estimate the engine efficiency, in the flowchart shown in FIG. 9, the process proceeds from step S30 to step S31 to step S32 to step S33, and from the engine torque command according to the conversion coefficient value corresponding to the current engine speed. The engine torque is obtained and the actual engine torque is calculated. When the current engine torque is calculated, the process proceeds to step S34, and an engine torque region corresponding to the calculated engine torque is set.

  On the other hand, in the flowchart shown in FIG. 9, the process proceeds from step S35 to step S36, and the engine efficiency is calculated based on the current engine fuel injection amount and the engine torque by the above equation (11).

  Then, in the flowchart shown in FIG. 9, the process proceeds from step S37 to step S38, step S39, step S40, and step S41, and an engine efficiency table in which engine efficiency is set for each engine speed region and engine torque region is created. That is, if the calculated engine efficiency is stored in association with both the engine speed range and the engine torque range, and the engine efficiency is calculated a predetermined number of times in the same engine speed range and engine torque range, the engine that is the average value is calculated. An efficiency value is obtained, and the engine speed range, the engine torque range, and the engine efficiency value are stored in association with each other. The engine efficiency value is obtained by a weighting method.

  After the engine efficiency table is created, the process proceeds to step S42, and the optimum fuel consumption line of the engine is determined by selecting the optimum fuel consumption torque that is the engine torque region in which the engine efficiency value is maximized for each engine speed range. Create an “optimum fuel consumption line map”.

  Thereby, it is possible to grasp the engine torque that maximizes the engine efficiency in accordance with the engine speed. Therefore, the engine 201 can be accurately controlled so as to be in an efficient state, and fuel consumption can be improved.

In the hybrid vehicle control apparatus according to the first embodiment, the engine efficiency is calculated a predetermined number of times in the same engine speed range and engine torque range, and an engine efficiency value that is an average value of the plurality of engine efficiencies is obtained. The engine torque that maximizes the engine efficiency value is set as the optimum fuel efficiency torque.
Thus, by calculating | requiring the average value of engine efficiency, the calculation precision of engine efficiency can be improved and the estimation precision of optimal fuel consumption torque can be improved.

[Motor assist function]
FIG. 17A is a characteristic diagram showing the relationship between the accelerator opening and the drive torque in the trailer truck of the first embodiment, and FIG. 17B is a characteristic diagram showing the motor assist torque.

  In the full trailer truck 1 of the first embodiment, in order to improve the fuel consumption of the engine 201, the engine 201 needs to be operated in a state where the engine efficiency is good. Generally, it has been found that the engine efficiency is good when the output torque is about 80% of the maximum output torque of the engine. On the other hand, since there is a limit to the amount of electric power for driving the motor generator 301, that is, the remaining battery level, for example, when driving on an uphill road, the scene in which drive assist is preferentially performed by the motor generator 301 is limited.

  Therefore, in the hybrid vehicle control apparatus of the first embodiment, the drive assist and shift down by the motor generator 301 are not executed until the output torque of the engine 201 reaches the engine torque region where the engine efficiency is maximum, that is, the optimum fuel efficiency torque. .

That is, in the flowchart shown in FIG. 13, the process proceeds from step S50 → step S51 → step S52 → step S53 → step S54, and the optimum fuel economy torque at the current engine speed is compared with the current engine torque. In FIG. 17, the current engine torque is less than the optimum fuel consumption torque (ETu in this case) until the accelerator opening reaches P ₁ , so the process proceeds to step S56 and motor assist by the motor generator 301 is not executed. Thus, the accelerator opening degree from zero up to the P ₁ becomes the driving force of the tractor 2 (engine driving force) = total driving force of the full trailer truck 1.

Then, when a P ₁ accelerator opening is increased, the current engine torque is greater than the optimum fuel efficiency torque (here ETu is). Accordingly, the process proceeds from step S54 to step S55 in the flowchart shown in FIG. 13, and the target motor torque for realizing the motor assist torque according to the accelerator opening and the total vehicle weight is output to the motor controller 311.
That is, the motor assist torque is output from the motor generator 301 as shown in FIG. As a result, the total driving force in the full trailer truck 1 can be increased as the accelerator opening increases. On the other hand, the engine torque is kept in the vicinity of the optimum fuel efficiency torque (ETu). Thereby, the fall of engine efficiency can be suppressed and a fuel consumption improvement can be aimed at.

  Here, the “motor assist torque” is set according to the accelerator opening and the total vehicle weight. Therefore, driving assistance can be performed without causing a sense of incongruity in the acceleration feeling with respect to the accelerator opening.

  When further driving force is required and the driver performs a downshift in the transmission 203, the process proceeds from step S57 to return in the flowchart of FIG. Thus, driving force assist by the motor generator 301 is not performed until the engine torque reaches the optimum fuel efficiency torque at the engine speed after the downshift.

  Thereby, the driving force assist by the motor generator 301 can be performed at an appropriate timing, and wasteful power consumption can be prevented.

Next, the effect will be described.
In the hybrid vehicle control device of the first embodiment, the following effects can be obtained.

(1) An engine drive shaft (propeller shaft) 204 that is rotationally driven by the engine 201, a motor drive shaft (propeller shaft) 302 that is rotationally driven by a motor (motor generator) 301, and an engine torque that estimates the engine torque of the engine 201 A hybrid vehicle comprising: estimation means (FIG. 6); and motor assist control means (FIG. 13) for rotationally driving the motor 301 to assist the driving force of the engine drive shaft 204 to control the engine torque. In the control device,
The engine torque estimation means (FIG. 6) is proportional to the engine torque, and is engine information detection means for detecting engine state information (engine torque command) displayed at a ratio to the maximum engine torque. Step S5 to Step S8, Step S10 to Step S13),
Driving force holding means (step S2) for holding a total driving force that is a sum of driving force of the engine driving shaft 204 and driving force of the motor driving shaft 302 constant;
Motor control means (step S9) for changing the motor torque by a predetermined amount while keeping the total driving force constant;
Conversion coefficient calculation means for calculating a conversion coefficient for converting the engine state information into the engine torque based on the change amount of the motor torque and the change amount of the engine state information accompanying the change in the motor torque (steps S14 to S14). Step S19)
Engine torque calculation means (steps S20 to S23) for calculating the engine torque based on the conversion coefficient and the engine state information;
It was set as the structure provided with.
Thereby, even when the torque characteristic of the engine 201 that rotationally drives the engine drive shaft 204 is unknown, the engine torque can be estimated using the torque of the motor 301 that rotationally drives the motor drive shaft 302.

(2) engine speed detecting means (step S30) for detecting the speed of the engine 201;
Fuel injection amount detection means (step S35) for detecting the fuel injection amount of the engine 201;
Engine efficiency calculating means (steps S36 to S41) for calculating engine efficiency according to the engine torque and the engine speed based on the engine torque, the fuel injection amount, and the engine speed;
Optimum fuel consumption torque estimating means (step S42) for estimating optimum fuel consumption torque, which is engine torque at which the engine efficiency is maximized, for each engine speed;
It was set as the structure provided with.
Thereby, it is possible to grasp the engine torque that maximizes the engine efficiency in accordance with the engine speed. Therefore, the engine 201 can be accurately controlled so as to be in an efficient state, and fuel consumption can be improved.

(3) The motor assist control means (FIG. 13) assists the driving force of the engine drive shaft 204 by rotationally driving the motor 301 when the engine torque becomes larger than the optimum fuel efficiency torque. The configuration.
As a result, the total driving force in the vehicle (full trailer truck 1) increases as the required driving force increases, while the engine torque can be maintained near the optimum fuel efficiency torque, and a decrease in engine efficiency can be suppressed. This can improve fuel efficiency.

(4) storage means (backup memory) 315a for storing the conversion coefficient,
The hybrid vehicle 1 is a connected vehicle (full trailer truck) 1 in which a tow vehicle (tractor) 2 having the engine drive shaft 204 and a towed vehicle (trailer) 3 having the motor drive shaft 302 are connected.
The storage means 315a is reset when the tow vehicle 2 and the towed vehicle 3 are disconnected, and is set to a preset initial value when the tow vehicle 2 and the towed vehicle 3 are connected.
Thereby, replacement of the tractor 2 that is a towing vehicle can be reliably detected, and the conversion coefficient can be calculated every time the engine 201 is different.

(5) The conversion coefficient calculation means (steps S14 to S19) determines the amount of change in the engine state information before the motor torque changes and the engine state information when the engine state information is stable ( The configuration is obtained from the difference between the engine torque command before motor driving) and the engine status information (engine torque command after motor driving) when the engine status information is stable after the motor torque has changed.
Thereby, the error of the engine torque command with respect to the actual engine torque is suppressed, and the engine torque calculation accuracy can be improved.

(6) The engine information detection means (step S5 to step S8, step S10 to step S13) stabilizes the engine state information when a change amount of the engine state information is within a predetermined range for a predetermined time. Therefore, the engine state information is detected.
As a result, the stable state of the engine torque command can be easily and accurately determined.

(7) The conversion coefficient calculation means (steps S14 to S19) calculates the conversion coefficient a plurality of times and averages the plurality of conversion coefficients to obtain an average value.
The engine torque calculation means (steps S20 to S3) is configured to calculate the engine torque based on the average value of the conversion coefficients and the engine state information.
Thereby, by calculating the average value of the conversion coefficients, the calculation accuracy of the conversion coefficients can be increased, and the calculation accuracy of the engine torque can be improved.

(8) The engine efficiency calculating means (steps S36 to S41) calculates the engine efficiency a plurality of times and averages the plurality of engine efficiencies to obtain an average value.
The optimum fuel consumption torque estimating means (step S42) is configured such that the optimum fuel consumption torque is an engine torque that maximizes the average value of the engine efficiency for each engine speed.
Thereby, by calculating the average value of the engine efficiency, it is possible to increase the calculation accuracy of the engine efficiency and improve the estimation accuracy of the optimum fuel efficiency torque.

(9) required driving force detecting means for detecting required driving force of the hybrid vehicle (full trailer truck) 1;
Vehicle weight detection means for detecting the weight of the hybrid vehicle,
The motor assist control means (FIG. 13) sets the assist torque of the motor 301 when assisting the driving force of the engine drive shaft 204 according to the required driving force and the vehicle weight.
As a result, it is possible to assist driving without causing a sense of incongruity in the acceleration according to the change in the required driving force.

(10) A transmission (transmission) 203 provided on the engine drive shaft 204 is provided,
The motor assist control means (FIG. 13) sets an upper limit value of the assist torque of the motor 301, and when the required driving force increases even if the assist torque reaches the upper limit value, the gear shift of the transmission 203 is performed. The ratio is reduced, and the rotation drive of the motor 301 is stopped.
Thereby, the driving force assist by the motor generator 301 can be performed at an appropriate timing, and wasteful power consumption can be prevented.

(11) In the hybrid vehicle control method for assisting the driving force of the engine drive shaft 204 driven to rotate by the engine 201 with the driving force of the motor drive shaft 302 driven to rotate by the motor 301,
A driving force holding procedure (step S2) for keeping the total driving force, which is the sum of the driving force of the engine driving shaft 204 and the driving force of the motor driving shaft 302, constant;
Engine state information (engine torque command) that is proportional to the engine torque and displayed as a percentage of the maximum engine torque before the motor torque changes in a state where the total driving force is held constant. A pre-motor drive engine information detection procedure to detect (steps S5 to S8);
A motor control procedure (step S9) for changing the motor torque by a predetermined amount while keeping the total driving force constant;
A post-motor engine information detection procedure (step S10 to step S13) for detecting the engine state information after a change in motor torque with the total driving force held constant;
A conversion coefficient calculation procedure for calculating a conversion coefficient for converting the engine state information into the engine torque based on the change amount of the motor torque and the change amount of the engine state information accompanying the change of the motor torque (steps S14 to S14). Step S19)
An engine torque calculation procedure (step S20 to step S23) for calculating the engine torque based on the conversion coefficient and the engine state information is provided.
Thereby, even if the torque characteristics of the engine are unknown, the engine torque can be estimated.

(12) an optimum engine torque setting procedure (step S51) for setting an optimum fuel efficiency torque that is an engine torque when the efficiency of the engine 201 is maximized;
An engine torque estimation procedure (step S53) for estimating the current engine torque of the engine 201;
A motor assist procedure (step S55) for assisting the driving force of the engine drive shaft by rotationally driving the motor when the current engine torque becomes larger than the optimum fuel efficiency torque;
It was set as the structure which has.
As a result, the total driving force in the vehicle (full trailer truck 1) increases as the required driving force increases, while the engine torque can be maintained near the optimum fuel efficiency torque, and a decrease in engine efficiency can be suppressed. This can improve fuel efficiency.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on Example 1, it is not restricted to these Examples about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the hybrid vehicle control apparatus of the first embodiment, the amount of change in the engine state information is obtained from the difference between the engine torque command before motor driving and the engine torque command after motor driving. However, the present invention is not limited to this. For example, as shown in FIG. 18, the amount of change in motor torque is the amount of change in motor torque (ΔMt) per predetermined time (Δtx) during the change in motor torque. The engine torque command change amount (ΔEt) per predetermined time (Δtx) during the motor torque change may be used.

  In other words, when the auto-cruise signal is in the ON state and the change amount of the engine torque command is within the predetermined range for a predetermined time (time t10 to t11 in FIG. 18), driving of the motor generator 301 is started. Then, the motor torque at this time (the motor regeneration amount in FIG. 18) is gradually increased, and the conversion coefficient is calculated from the motor torque increase (ΔMt) in a certain time (Δtx) and the change amount (ΔEt) of the engine torque command. calculate.

  Depending on the accuracy of the auto cruise control, it may take time for the engine torque command to stabilize, which may cause a conversion error calculation error. No need to wait. As a result, the conversion coefficient can be obtained accurately in a short time. Further, the energy consumed by the motor generator 301 by regenerative control can be reduced.

  In this case, the change amount of the engine torque command may be obtained a plurality of times during the change of the motor torque, and the average value thereof may be used as the change amount of the engine torque command. By calculating the average value, the accuracy can be further increased.

  Furthermore, in the hybrid vehicle control device of the first embodiment, the engine torque command is used as the driving state information indicating the driving state of the engine 201. However, the present invention is not limited thereto, and has a proportional relationship with the actual engine torque. In addition, any information may be displayed as a ratio with respect to the maximum engine torque. That is, for example, it may be an engine fuel injection amount, an engine air supply / exhaust amount, a throttle opening, and the like.

  Furthermore, in the hybrid vehicle control apparatus of the first embodiment, the motor generator 301 that can perform the operation as the electric motor and the operation as the generator is used as the motor. I can do it. Further, as long as the engine torque is only estimated, a motor having only a function as a generator may be used.

  Furthermore, in the hybrid vehicle control device of the first embodiment, the stepped automatic transmission is used as the transmission, but a manual transmission that manually changes the shift stage may be used.

  In the first embodiment, an example in which the hybrid vehicle control device is applied to the full trailer truck 1 is shown. However, any vehicle having an engine drive shaft and a motor drive shaft may be used. In other words, in addition to semi-trailer trucks and multi-coupled full trailer trucks where the towed vehicle is engine driven and the towed vehicle is a motor driven vehicle, the front axle is engine driven and the rear axle is free, and the rear axle is motor driven. It may be a modified car modified to be. Furthermore, the present invention can also be applied to a railway vehicle that connects a connected vehicle to a towing vehicle driven by a diesel engine.

1 Full trailer truck (hybrid vehicle)
2 Tractor
201 Engine 202 Clutch 203 Transmission 204 Propeller shaft (engine drive shaft)
211 Brake device 213 Display device 221 Engine controller 222 AT controller 223 Brake controller 230 CAN communication line 3 Trailer (towed vehicle)
301 Motor generator (motor)
302 Propeller shaft (motor drive shaft)
311 Motor controller 312 Inverter 313 Battery 314 Battery controller 315 Integrated controller 315a Backup memory (storage means)

Claims (4)

An engine drive shaft that is rotationally driven by an engine, a motor drive shaft that is rotationally driven by a motor, engine torque estimating means for estimating an engine torque of the engine, and assisting the driving force of the engine drive shaft by rotationally driving the motor And a motor-assisted control means for controlling the engine torque, and a hybrid vehicle control device comprising:
The engine torque estimating means includes
Engine information detection means for detecting engine state information that is proportional to the engine torque and is displayed as a percentage of the maximum engine torque;
Driving force holding means for holding constant the total driving force which is the sum of the driving force of the engine driving shaft and the driving force of the motor driving shaft;
Motor control means for changing the motor torque by a predetermined amount while keeping the total driving force constant;
Conversion coefficient calculating means for calculating a conversion coefficient for converting the engine state information into the engine torque based on the change amount of the motor torque and the change amount of the engine state information accompanying the change of the motor torque;
Engine torque calculation means for calculating the engine torque based on the conversion coefficient and the engine state information;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 1,
Engine speed detecting means for detecting the engine speed;
Fuel injection amount detection means for detecting the fuel injection amount of the engine;
Engine efficiency calculating means for calculating engine efficiency according to the engine torque and the engine speed based on the engine torque, the fuel injection amount, and the engine speed;
Optimum fuel consumption torque estimating means for estimating an optimum fuel consumption torque that is an engine torque at which the engine efficiency is maximized for each engine speed;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 2,
The motor assist control means controls the hybrid vehicle to assist the driving force of the engine drive shaft by rotationally driving the motor when the engine torque becomes larger than the optimum fuel efficiency torque. apparatus. In the control apparatus of the hybrid vehicle as described in any one of Claims 1-3,
Storage means for storing the conversion coefficient;
The hybrid vehicle is a connected vehicle in which a tow vehicle having the engine drive shaft and a towed vehicle having the motor drive shaft are connected,
The control device for a hybrid vehicle, wherein the storage means is reset when the tow vehicle and the towed vehicle are disconnected, and is set to a preset initial value when the tow vehicle and the towed vehicle are connected.