JP5982783B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to an engine and transmission control device.

  In a conventional vehicle control device, such as an engine and transmission control device, an accelerator operation amount by a driver is input to an engine controller (hereinafter referred to as an engine ECU) and a transmission controller (hereinafter referred to as a transmission ECU). Therefore, the engine and the transmission are operated (see, for example, Patent Document 1).

  As a map for controlling the engine and the transmission, for example, there is a map as shown in FIG. 8 showing the correlation between the accelerator opening, the engine speed, the engine torque, and the engine output. In FIG. 8, a thick line A is a line connecting the points where the fuel injection amount per unit time is the smallest on the constant force line (hereinafter referred to as the minimum fuel injection amount line). If the engine is operated on this minimum fuel injection amount line, it is possible to continue the engine operation at the point where the fuel injection amount is the smallest for each output.

JP 2008-281057 A

  By the way, in a general engine and transmission control device, the engine is directly controlled in accordance with the accelerator operation amount. Therefore, the engine is not necessarily operated on the minimum fuel injection amount line. That is, the engine is operated using every point on the map of FIG. 8 according to the accelerator operation amount. The accelerator operation amount is also input to the transmission ECU, and is used to determine the transmission gear ratio. However, since the gear stage of the transmission is also set by a two-dimensional map of the vehicle speed and the accelerator opening, it is not always set to operate the engine on the minimum fuel injection amount line. Therefore, the efficiency of the engine is generally recognized as 30 to 40%, but this is the efficiency in the vicinity of the region B on the map of FIG. 8, and other regions are also used at the actual driving level. The engine efficiency is reduced to 10-20%.

  One technique for improving the efficiency of such an engine is called coasting control. In this coasting control, the engine is operated with the idling engine speed at which the fuel injection amount per unit time is minimized and the accelerator opening degree being zero when the engine output is zero (range of thick line C in FIG. 8). In other words, according to coasting control, wasteful fuel consumption can be suppressed by disengaging the clutch to reduce the accelerator opening to zero and dropping the engine to idle rotation.

  However, the application range of coasting control is limited to the range where the engine output is near zero (the range of the thick line C in FIG. 8), and therefore cannot be applied when the engine output is away from the vicinity of zero. The fuel consumption cannot be improved effectively.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicle capable of effectively improving the fuel consumption of an engine while enabling the vehicle to travel by a driver with a minimum fuel injection amount. It is to provide a control device.

In order to achieve the above object, a vehicle control apparatus according to the present invention is a vehicle control apparatus in which driving force of an engine is transmitted to drive wheels via a transmission, and an accelerator opening degree detection that detects an accelerator opening degree. Means, a rotation speed detection means for detecting the output rotation speed of the transmission, and a first output rotation speed line such as a plurality of transmissions on a coordinate plane corresponding to the accelerator opening and the engine output. The engine output setting means for setting the engine output of the engine by reading the engine output corresponding to the detected accelerator opening and the output rotational speed from the map, and corresponding to the engine output and the fuel injection amount The minimum fuel injection amount corresponding to the set engine output is read from the second map in which the minimum fuel injection amount line that minimizes the fuel injection amount of the engine is set on the coordinate plane. And a target fuel injection amount setting means for setting the target fuel injection amount of the engine, and a third map in which an engine speed line is set on a coordinate plane corresponding to the engine output and the engine speed. A target engine speed setting means for setting a target engine speed of the engine by reading an engine speed corresponding to the engine output, and the detected output speed and the set target engine speed Based on the above, a target speed ratio calculating means for calculating a target speed ratio of the transmission, an engine control means for controlling the engine so that the fuel injection amount of the engine becomes the target fuel injection amount, and the speed change Transmission control means for controlling the transmission so that the transmission gear ratio becomes the target gear ratio, and shift range position detection for detecting the shift range position And the engine speed line of the third map is set so that the engine speed increases as the engine output decreases in the engine output negative region, and in the first map, The output rotation speed line such as a transmission is set so that the engine output increases as the accelerator opening increases, and the increase rate of the engine output increases as the output rotation speed increases. Correspondingly, a plurality of engine outputs are set, and an increase rate of the engine output is set to be smaller as the shift range becomes a higher speed range. According to the vehicle control apparatus of the present invention, the engine output setting means sets the engine output according to the detected accelerator opening and the output rotational speed of the transmission from the first map, and sets the target fuel injection amount. The means sets the target fuel injection amount of the engine according to the set engine output from the second map, and the target engine speed setting means sets the engine target according to the set engine output from the third map. Set the engine speed. Further, the target speed ratio calculating means calculates a target speed ratio of the transmission based on the detected output speed and the set target engine speed, and the engine control means determines that the fuel injection amount of the engine is the target fuel. The engine is controlled to achieve the injection amount, and the transmission control means controls the transmission so that the transmission gear ratio becomes the target transmission gear ratio. In the second map, the minimum fuel injection amount line that minimizes the fuel injection amount of the engine is set on the coordinate plane corresponding to the engine output and the fuel injection amount, and the target fuel injection amount setting means The target fuel injection amount of the engine is set by reading the minimum fuel injection amount according to the output. Therefore, the fuel consumption of the engine can be effectively improved while enabling the vehicle to travel as desired by the driver with the minimum fuel injection amount.

Further, the minimum fuel injection amount line of the second map is set so that the fuel injection amount becomes zero in the region on the negative side of the engine output . In the first map, the output of the plurality of transmissions, etc. The rotation speed lines may be set so as to converge with each other as the accelerator opening increases .

Also, the transmission may be a continuously variable transmission.

  According to the vehicle control apparatus of the present invention, the fuel consumption of the engine can be effectively improved while enabling the vehicle to travel as desired by the driver with the minimum fuel injection amount.

1 is a schematic block diagram illustrating a vehicle control device according to an embodiment of the present invention. It is a functional block diagram which shows each ECU of the control apparatus of the vehicle which concerns on one Embodiment of this invention. It is a figure which shows the relationship between the accelerator opening of the control apparatus of the vehicle which concerns on one Embodiment of this invention, and the engine output for every transmission output rotation speed. It is a figure which shows the minimum fuel injection amount line of the control apparatus of the vehicle which concerns on one Embodiment of this invention. It is a figure which shows the relationship between the engine output and fuel injection quantity of the control apparatus of the vehicle which concerns on one Embodiment of this invention. It is a figure which shows the relationship between the engine output of the vehicle control apparatus which concerns on one Embodiment of this invention, and an engine speed. It is a flowchart which shows the control content by the control apparatus of the vehicle which concerns on one Embodiment of this invention. It is a figure which shows the map used for the control of the conventional engine and a transmission.

  Hereinafter, based on FIGS. 1-7, the control apparatus of the vehicle which concerns on one Embodiment of this invention is demonstrated. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  As shown in FIG. 1, a vehicle 1 is equipped with a diesel engine (hereinafter simply referred to as an engine) 10 as an internal combustion engine. The output shaft of the engine 10 is connected to the input shaft of the continuously variable transmission 12 via the clutch 11. The output shaft of the continuously variable transmission 12 is connected to the drive wheels 16 via the propeller shaft 13, the final reduction gear 14, and the drive shaft 15. That is, when the clutch 11 is connected, the driving force of the engine 10 is continuously shifted by the continuously variable transmission 12 and then the driving wheel 16 via the propeller shaft 13, the final reduction gear 14, and the drive shaft 15. It is configured to be transmitted to.

An accelerator sensor 18 is for detecting an operation amount of the accelerator pedal by the driver, the detected operation amount is output to the arithmetic ECU40 electrically connected as an accelerator opening A _p.

Speed sensor 19 is for detecting the output speed of the continuously variable transmission 12, the detected output rotational speed is outputted to the arithmetic ECU40 electrically connected as the transmission output rotational speed N _t.

  The shift position sensor 17 detects an operation position of the shift lever 4 (hereinafter referred to as a shift range), and each detected shift range is output to the arithmetic ECU 40 that is electrically connected.

The engine ECU 20 performs various controls such as fuel injection of the engine 10 and includes a known CPU, ROM, RAM, input port, output port, and the like. The engine ECU 20 is connected to the arithmetic ECU 40 via electric wiring so as to be able to communicate with each other, and controls the operating state of the engine 10 in accordance with a control signal input from the arithmetic ECU 40. More specifically, as the fuel injection amount of the engine 10 becomes the target fuel injection amount F _t which is input from the operation ECU 40, it is configured to apply a current of a predetermined pulse to the electromagnetic solenoid of the injector (not shown).

The transmission ECU 30 controls the operation of the continuously variable transmission 12, and includes a known CPU, ROM, RAM, input port, output port, and the like. The transmission ECU 30 is connected to the arithmetic ECU 40 via an electrical wiring so as to be able to communicate with each other, and controls the gear ratio of the continuously variable transmission 12 according to a control signal input from the arithmetic ECU 40. Specifically, as the gear ratio of the continuously variable transmission 12 becomes the target speed ratio S _t which is input from the operation ECU 40, and is configured to output a predetermined operation signal to the gear shift actuator (not shown).

Calculation ECU40 is for calculating a target gear ratio S _t of the target fuel injection amount F _t and the continuously variable transmission 12 of the engine 10, known as well as the previous engine ECU20 and the transmission ECU 30 CPU and ROM, RAM, An input port, an output port, and the like are provided. To compute these target fuel injection amount F _t and the target speed ratio S _t, the arithmetic ECU40 an accelerator sensor 18, speed sensor 19, the output signals of various sensors of the vehicle speed sensor or the like, not the shift position sensor 17 and shown, Input after A / D conversion.

  As shown in FIG. 2, the calculation ECU 40 includes an engine output setting unit 41, a target fuel injection amount setting unit 42, a target engine speed setting unit 43, and a target gear ratio calculation unit 44 with some functions. Have as an element. In the present embodiment, these functional elements are described as being included in the arithmetic ECU 40, which is an integral piece of hardware, but any one of these functional elements can be provided in separate hardware.

The engine output setting unit 41 is a target engine output W of the engine 10 based on the accelerator opening A _p input from the accelerator sensor 18 and the transmission output rotation speed N _t input from the rotation speed sensor 19. Set _e . More specifically, the calculation ECU 40 has an engine output map (first map) shown in FIG. 3 showing the relationship between the accelerator opening _Ap and the engine output W for each transmission output rotation speed, which is created in advance through experiments or the like. It is remembered. In this engine output map, a plurality of transmission output speed lines (see thick lines in FIG. 3) are set at a predetermined speed on a coordinate plane with the horizontal axis representing the accelerator opening A _p and the vertical axis representing the engine output W. It is set for each. On engine power map, the transmission such as output speed line is set so that the engine output W increases as the accelerator opening degree A _p increases. Further, the output rotation speed line such as a transmission is set such that the increase rate of the engine output W increases as the output rotation speed increases. Engine power setting unit 41, the engine power map, by reading the engine output W corresponding to the accelerator opening A _p and the transmission output speed N _t, sets the engine power W _e as a target of the engine 10 . Thus the engine output W _e that is set is configured to be input to the target fuel injection amount setting unit 42 and the target engine rotation speed setting unit 43, which will be described in detail later.

Target fuel injection amount setting unit 42 based on the engine output W _e set by the engine power setting unit 41 sets the target fuel injection amount F _t of the engine 10. More specifically, the calculation ECU40 has replaced a map indicating the minimum fuel injection amount line in FIG. 4, the output injection amount map showing a relationship between the engine output W _e and the fuel injection amount F in FIG. 5 (second map ) Is stored. The output injection amount map, the engine horizontal axis output W _e, the vertical axis on the coordinate plane which is a fuel injection amount F, minimum fuel injection quantity line for the least fuel injection quantity of the engine 10 (in FIG. 5 Thick line reference) is set. In particular, the minimum fuel injection amount line, the positive-side region of the engine output W _e, as the engine output W _e increases, while being set so that the fuel injection amount F is increased, the negative side of the engine output W _e In the region, the fuel injection amount F is set to be 0 (zero).

Target fuel injection amount setting portion 42, by reading the fuel injection amount F corresponding to the engine output W _e from the output injection amount map, and sets the target fuel injection amount F _t, the target fuel injection amount F _t set It is configured to output to the engine ECU 20. As a result, a current of a predetermined pulse corresponding to the target fuel injection amount F _t is applied from the engine ECU 20 to an electromagnetic solenoid of an injector (not shown), and the fuel injection amount of the engine 10 is controlled to become the target fuel injection amount F _t. .

Target engine rotational speed setting unit 43, based on the engine output W _e set by the engine power setting unit 41 sets the target engine speed N _e of the engine 10. More specifically, the calculation ECU40 has replaced a map shown in FIG. 4, the output rotational speed map showing a relationship between the engine output W _e and the engine speed N in FIG. 6 is stored. Further, in this output speed map, the optimum engine speed line corresponding to the output of the engine 10 (thick line in FIG. 6) is plotted on a coordinate plane with the horizontal axis representing the engine output W _e and the vertical axis representing the engine speed N. Reference) is set. Optimal engine speed lines, the positive-side region of the engine output W _e, as the engine output W _e increases, while the engine speed N _e is set to rise, the negative-side region of the engine output W _e is The engine speed N _e is set to increase as the engine output W _e decreases. The target engine speed setting unit 43 is configured to set the target engine speed N _e by reading the engine speed N corresponding to the engine output W _e from the output speed map.

Target transmission ratio calculation unit 44, the transmission input from the rotational speed sensor 19 outputs the rotation speed N _t and, based on the target engine speed N _e set by the target engine rotation speed setting unit 43, the continuously variable transmission 12 target gear ratio R _tm is calculated. Here, the target speed ratio R _tm can be calculated by the following equation (1).
R _tm = N _e / N _t (1)

The target speed ratio R _tm calculated in this way is output to the transmission ECU 30. Accordingly, the hydraulic signal according to the target speed ratio S _t to the shift actuator (not shown) from the transmission ECU30 is input, the gear ratio of the continuously variable transmission 12 is controlled to be a target gear ratio S _t.

  Next, a control flow by the vehicle control apparatus according to the present embodiment will be described with reference to FIG. This control starts simultaneously with the start of the engine 10 (key switch ON of the ignition switch).

Step (hereinafter referred to as simply S Step) At 100, the engine output setting unit 41, the accelerator opening A _p input from the accelerator sensor 18, transmission output speed input from the speed sensor 19 N based on the _t, engine power W _e of the engine 10 from the engine output map shown in FIG. 3 is set.

In S110, the target fuel injection amount setting unit 42, by the fuel injection amount F corresponding to the engine output W _e from the output injection amount map is set in S100 described above shown in FIG. 5 is read, the target fuel injection amount F _t is set.

In S120, the engine output W _e, which is set in S100 is whether the positive region, or whether the negative region is confirmed. If it is the positive region, the process proceeds to S130, and if it is the negative region, the process proceeds to S140. When the process proceeds to S130, the target engine speed N _e is set by reading the engine speed N corresponding to the engine output W _e from the output speed map shown in FIG. Is done.

On the other hand, if the process proceeds to S140 are the target engine rotational speed setting unit 43, when the engine speed N corresponding from the output rotational speed map in the engine output W _e shown in FIG. 6 is read, the target engine speed N _e Is set. Further, in S160, the target transmission ratio calculating section 44, the transmission input from the rotational speed sensor 19 outputs the rotation speed N _t and, based on the target engine speed N _e, which is set in S130 or S150 described above, no A target speed ratio R _tm of the step transmission 12 is calculated.

In S170, the target fuel injection amount F _t set in S110 described above is, is input from the arithmetic ECU40 to the engine ECU 20, the target speed ratio R _tm calculated in S160 of the aforementioned, the transmission ECU30 from operation ECU40 Entered. Furthermore, in S180, it is controlled so that the fuel injection amount of the engine 10 becomes the target fuel injection amount F _t, and the gear ratio of the continuously variable transmission 12 is controlled by a return to be a target speed ratio R _tm The Thereafter, each step from S100 to S180 of this control is repeatedly performed until the engine 10 is stopped (key switch of the ignition switch is turned off).

  Next, effects of the vehicle control apparatus according to the present embodiment will be described.

In the vehicle control apparatus of the present embodiment, the engine output shown in FIG. 3 is based on the accelerator opening degree A _p detected by the accelerator sensor 18 and the transmission output rotational speed N _t detected by the rotational speed sensor 19. engine output W _e is set from the map.

Then, the engine output W _e that is set is used to set the output injection amount map shown in FIG. 5 of the target fuel injection amount F _t corresponding to the minimum fuel injection quantity line. Further, the set engine output W _e is used for setting the target engine speed N _e from the output speed map shown in FIG. Further, the target speed ratio R _tm of the continuously variable transmission 12 is calculated based on the set target engine speed N _e and the transmission output speed N _t detected by the speed sensor 19. In this way, the set target fuel injection amount F _t is is output to the engine ECU 20, the target speed ratio R _tm is configured to be outputted to the transmission ECU 30. Thus, the fuel injection amount of the engine 10 is controlled to be the target fuel injection amount F _t , and the gear ratio of the continuously variable transmission 12 is controlled to be the target gear ratio R _tm .

  Therefore, according to the vehicle control apparatus of the present embodiment, the operating state of the engine 10 and the gear ratio of the continuously variable transmission 12 according to the driver's accelerator operation are uniquely determined from the simple engine output map shown in FIG. Can be determined. Furthermore, the fuel consumption of the engine 10 can be improved while allowing the vehicle to travel as desired by the driver with the minimum fuel injection amount.

Further, in the control apparatus for a vehicle of the present embodiment, as shown in the output injection amount map of FIG 5, the negative-side region of the engine output W _e, the fuel injection amount F is set to be 0 (zero) Yes. Furthermore, as shown in the output rotational speed map of Fig. 6, in the negative-side region of the engine output W _e, as the engine output W _e is decreased, the engine rotational speed N is set to rise.

Therefore, according to the control apparatus for a vehicle of the present embodiment, the negative-side region of the engine output W _e, by not performing unnecessary fuel injection, it is possible to effectively improve the fuel consumption of the engine 10, the engine By increasing the rotational speed, the engine brake can be effectively applied.

In the vehicle control apparatus of the present embodiment, a plurality of engine outputs are set corresponding to each shift range, as shown in the engine output map of FIG. In this engine output map, the engine output increase rate is set to be smaller as the shift range becomes a higher speed range.

  Therefore, since the engine braking force is switched according to the shift range in the engine output negative side region, the vehicle speed can be maintained at a constant speed while the vehicle is traveling downhill, etc., and driving operability can be improved. it can. Furthermore, fuel consumption can be improved by eliminating unnecessary deceleration, and the life of a brake device of a vehicle can be effectively improved by reducing use of unnecessary brakes.

  In addition, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning of this invention, it can change suitably and can implement.

  For example, in the above-described embodiment, each of the ECUs 20, 30, and 40 has been described as being provided in separate hardware, but some or all of these may be provided as integral hardware.

  The engine 10 is not limited to a diesel engine, and can be widely applied to other internal combustion engines such as a gasoline engine.

10 engine 12 continuously variable transmission (transmission)
17 Shift position sensor (shift range detection means)
18 Accelerator sensor (accelerator opening detection means)
19 Rotational speed sensor (Rotational speed detection means)
20 engine ECU (engine control means)
30 Transmission ECU (transmission control means)
40 arithmetic ECU
41 Engine output setting unit (transmission output torque setting means)
42 target fuel injection amount setting unit (target fuel injection amount setting means)
43 Target engine speed setting unit (target engine speed setting means)
44 Target speed ratio calculating unit (target speed ratio calculating means)

Claims (3)

A vehicle control device in which driving force of an engine is transmitted to driving wheels via a transmission,
An accelerator opening detecting means for detecting the accelerator opening;
A rotational speed detection means for detecting an output rotational speed of the transmission;
According to the detected accelerator opening and the output rotational speed from the first map in which the output rotational speed lines such as a plurality of transmissions are set on the coordinate plane corresponding to the accelerator opening and the engine output. Engine output setting means for setting the engine output of the engine by reading the engine output;
The minimum fuel corresponding to the set engine output from the second map in which the minimum fuel injection amount line that minimizes the fuel injection amount of the engine is set on the coordinate plane corresponding to the engine output and the fuel injection amount. Target fuel injection amount setting means for setting the target fuel injection amount of the engine by reading the injection amount;
By reading the engine speed corresponding to the set engine output from the third map in which the engine speed line is set on the coordinate plane corresponding to the engine output and the engine speed, the target engine of the engine Target engine speed setting means for setting the speed,
Target speed ratio calculating means for calculating a target speed ratio of the transmission based on the detected output speed and the set target engine speed;
Engine control means for controlling the engine so that the fuel injection amount of the engine becomes the target fuel injection amount;
Transmission control means for controlling the transmission so that the transmission gear ratio becomes the target gear ratio;
Shift range position detecting means for detecting the shift range position,
The engine speed line of the third map is set so that the engine speed increases as the engine output decreases in the engine output negative region,
In the first map,
The output speed line such as the transmission is set so that the engine output increases as the accelerator opening increases, and the increase rate of the engine output increases as the output speed increases.
A control apparatus for a vehicle, wherein a plurality of engine outputs are set corresponding to each shift range, and the increase rate of the engine output is set to be smaller as the shift range becomes a higher speed range . The minimum fuel injection amount line of the second map is set so that the fuel injection amount becomes zero in the region on the negative side of the engine output . In the first map, the output speed of the plurality of transmissions, etc. The vehicle control device according to claim 1 , wherein the lines are set so as to converge with each other as the accelerator opening increases . The transmission control apparatus for a vehicle according to claim 1 or 2 which is a continuously variable transmission.