JP2000245016A - Electric vehicle and control thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust constant-speed run and deceleration properly by selectively implement a speed control means and a deceleration control means based on the setting of a target value. SOLUTION: A hybrid vehicle realizes deceleration higher/lower than deceleration by an engine brake by switching the operating condition of a motor 20 between regenerative running and power running. A map is set so that the area of the deceleration realized by the power running in a gear stage having a large gear ratio and the area of the deceleration realized by the regenerative running in the gear stage having a small gear ratio may be overlapped. This setting permits braking so as to be suitable for the remaining capacity SOC of a battery 50. When the battery 50 is under an additionally chargeable condition, for example, the gear stage having the small gear ratio is selected by the regenerative running of the motor 20, and the battery 50 is under a roughly full-charged condition, the gear stage having the large gear ratio is selected by the power running of the motor 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric vehicle powered by at least an electric motor and a control method thereof.
More specifically, the present invention relates to an electric vehicle capable of arbitrarily adjusting the acceleration of the vehicle and a control method for realizing the braking.

[0002]

2. Description of the Related Art In recent years, a hybrid vehicle using an engine and an electric motor as power sources has been proposed as one form of an electric vehicle. For example, in the hybrid vehicle described in Japanese Patent Application Laid-Open No. 9-37407, an electric motor is added in series between the engine and the transmission to the power system of a normal vehicle in which the output shaft of the engine is connected to the drive shaft via the transmission. This is a vehicle having the following configuration. According to such a configuration, it is possible to travel using both the engine and the electric motor as power sources. Generally, when the vehicle starts moving, the fuel efficiency of the engine is poor. The hybrid vehicle starts using the power of the electric motor to avoid such driving. After the vehicle reaches a predetermined speed, the engine is started and the vehicle runs using the power.
Therefore, the hybrid vehicle can improve fuel efficiency at the time of starting. In addition, the hybrid vehicle can perform braking by regenerating the rotation of the drive shaft as electric power by an electric motor (hereinafter, such braking is referred to as regenerative braking). A hybrid vehicle can use kinetic energy without waste by regenerative braking. Due to these features, the hybrid vehicle has an advantage of excellent fuel economy.

[0003] A braking method for a vehicle includes a method of applying friction to an axle by pressing a pad or the like in response to operation of a brake pedal (hereinafter simply referred to as a wheel brake).
And a braking method of applying a load from a power source to a drive shaft like a so-called engine brake (hereinafter referred to as a power source brake). In a hybrid vehicle, power source braking includes engine braking based on engine pumping loss and regenerative braking by a regenerative load on an electric motor. Braking by a power source is useful in that braking can be performed without stepping from an accelerator pedal to a brake pedal. In order to enhance the usefulness of the power source brake, it is desirable that the deceleration intended by the driver can be arbitrarily set.

Here, the engine brake is operated as long as the opening / closing timing of the intake valve and the exhaust valve is not changed.
The braking force becomes a substantially constant value according to the engine speed. Therefore, in order for the driver to obtain a desired deceleration by the engine brake, the gear ratio of the transmission is changed by operating the shift lever, and the ratio of the torque of the power source to the torque output to the drive shaft is changed. I needed to. On the other hand, the regenerative braking of the electric motor has an advantage that the regenerative load can be controlled relatively easily, and the control of the deceleration can be realized relatively easily. From this viewpoint, in the hybrid vehicle described in Japanese Patent Application Laid-Open No. 9-37407, the deceleration set by the user is realized by controlling the regenerative braking force of the electric motor.

[0005] On the other hand, conventionally, there has been proposed a vehicle equipped with a constant speed traveling system for traveling at a set constant vehicle speed in a normal vehicle using only an engine as a power source.
The constant speed traveling system is a system that controls the torque of a power source so that a constant vehicle speed is obtained. When the constant-speed traveling system functions, the driver can travel at a desired vehicle speed without operating the accelerator pedal or the brake pedal, so that there is an advantage that the burden on the driver can be reduced. A hybrid vehicle equipped with an electric motor as a power source can control the torque of the power source with higher accuracy. Therefore, it is expected that if the constant speed traveling system is mounted on the hybrid vehicle, smoother traveling than before can be realized.

[0006]

However, in a vehicle equipped with both a constant-speed traveling system and a braking system in which the driver can adjust the deceleration by the power source brake, the functions of both cannot be sufficiently realized. It was found that there was.

[0007] The constant speed traveling system is a system in which a control device controls the operation of a power source so that the vehicle can travel at a target vehicle speed. When the current vehicle speed is higher than the target vehicle speed, the vehicle may be braked. On the other hand, the above-described braking system is a system in which the driver sets an arbitrary braking torque and controls the operation of the power source with the torque. Therefore, if both functions simultaneously, there is a possibility that the braking force set by the constant-speed traveling system and the braking torque set by the braking system are set to different values. In such a case, if the vehicle is driven with the braking torque set by the braking system, the vehicle speed intended by the driver cannot be maintained. Conversely, if the vehicle is driven with the target torque set by the constant speed traveling system, the deceleration intended by the driver cannot be realized. There is a possibility that the vehicle runs in a manner contrary to the driver's intention.

[0008] The various problems described above are not limited to a hybrid vehicle using an engine and an electric motor as power sources.
This was also a common problem for vehicles using only an electric motor as a power source (hereinafter, both are referred to as an electric vehicle). The present invention has been made to solve such a problem, and an electric vehicle that realizes traveling in a traveling state intended by a driver by appropriately using functions for realizing constant speed traveling and deceleration adjustment, and an electric vehicle therefor. It is an object to provide a control method.

[0009]

Means for Solving the Problems and Their Functions and Effects In order to solve at least a part of the above-mentioned problems, the present invention has the following configuration. An electric vehicle according to the present invention has an axle coupled to a power source including at least an electric motor, and is an electric vehicle that can be driven by the torque of the power source, and has target speed setting means for setting a target speed of the vehicle. Speed control means for controlling the power source so as to run at the target speed, target deceleration setting means for setting a target deceleration of the vehicle, and deceleration at the set target deceleration. Selectively controlling the speed control means and the deceleration control means in accordance with the last one of the target speed setting means among the target speed setting means and the target deceleration setting means for controlling the motor. And means for executing the program.

According to this electric vehicle, the speed control means and the deceleration control means can be selectively used according to the last set target value of the target speed and the target deceleration.
Usually, the driver requests that the vehicle be driven with the last set target value. Therefore, according to the electric vehicle of the present invention, the driver can drive the vehicle without discomfort.

In the electric vehicle according to the present invention, the operability of the vehicle can be improved by selectively using the speed control means and the deceleration control means. When the speed control means is being executed, the burden on the driver operating the vehicle is greatly reduced. On the other hand, in general, during driving of a vehicle, it is important to be able to realize a braking force according to the driver's intention in order to improve drive feeling. According to the electric vehicle of the present invention, when the deceleration control unit is being executed, the deceleration is performed at the target deceleration intended by the driver, so that the drive feeling can be greatly improved. The deceleration refers to a rate of change at which the speed of the vehicle decreases.

The use of the speed control means and the deceleration control means in the electric vehicle of the present invention will be described more specifically. For example, when the target speed is set by the target speed setting means, the speed control means is selected and the control by the means is executed. Thereafter, when the target deceleration is set by the target deceleration setting means, the deceleration control means is selected and the control by the means is executed. When the target speed is set again, the control by the speed control means is executed. In the electric vehicle of the present invention, the control according to the target value set later in time is sequentially performed as described above.

The setting of the target value can be determined in various ways. For example, when the setting of the target speed and the target deceleration is changed, it can be determined that a new target value has been set. In such a case, since the control according to the target value is realized together with the setting of the target value, it is possible to realize a driving without a sense of incongruity and to reduce the operation burden on the driver.

On the other hand, in the case where the driver is provided with a designating means for designating ON / OFF for each of the speed control and the deceleration control, the setting of the target value becomes effective for the side for which ON is designated last. You can also judge.

[0015] In this case, the selection of the acceleration setting means is performed in accordance with the driver's own operation, so that a more comfortable running can be realized. In addition, if a desired target value is set in advance and ON is specified, it is possible to realize traveling without a sense of incongruity in a transition period when the target value is changed.

In either case, when one of the target speed and the target deceleration is set, the other setting may be canceled or maintained.

The electric vehicle referred to in this specification includes various types of vehicles. The first is a vehicle using only an electric motor as a power source, a so-called pure electric vehicle. Second, a hybrid vehicle uses both an engine and an electric motor as power sources. Hybrid vehicles include a parallel hybrid vehicle that cannot transmit power from the engine directly to the drive shaft, and a series hybrid vehicle that uses power from the engine only for power generation and is not directly transmitted to the drive shaft. The present invention is applicable to both hybrid vehicles. Needless to say, the present invention can be applied to a motor having three or more motors including a motor as a power source.

As described above, the electric vehicle described above may include an engine other than the electric motor as a power source. When only the electric motor is used as the power source, the electric motor torque setting means sets the torque so that all of the desired braking force is applied by the electric motor. Generally, the torque is negative,
The electric motor performs so-called regenerative operation. When a motor other than the motor is included as a power source, the motor torque setting means sets the torque by the motor in consideration of the braking force provided by the motor. In such a case, the braking force of the motor may be treated as a predetermined value, or the torque of the electric motor may be so-called feedback controlled so that the overall braking force becomes a predetermined value.

As described above, the present invention is applicable to various electric vehicles, but it is preferable that the power source is an electric motor and an engine. That is, it is desirable to apply to a so-called parallel hybrid vehicle.

The control of the engine torque has characteristics that the response and the accuracy are relatively low. In particular, it is difficult to flexibly control the braking force when applying an engine brake. On the other hand, the electric motor has a feature that the torque can be controlled with high responsiveness and high accuracy. If the present invention is applied to the above-described hybrid vehicle, smooth acceleration / deceleration can be realized while taking advantage of the case where an engine is used as a power source. That is, the present invention is highly useful for the above-described hybrid vehicle.

In the electric vehicle of the present invention, a transmission capable of changing a plurality of gear ratios between the torque of the power source and the torque of the axle is coupled to the power source and the axle. It is preferable that the apparatus further includes a speed ratio selection unit that selects a speed ratio capable of realizing the target acceleration by the torque of the power source.

According to such a vehicle, the torque transmitted to the axle can be changed in a wide range by variously changing the gear ratio. Therefore, the acceleration of the vehicle can be adjusted in a wide range, and the operability of the vehicle can be improved.

The present invention can also be configured as a control method for an electric vehicle as described below. That is, the control method of the present invention is a control method of an electric vehicle having an axle coupled to at least a power source including an electric motor and capable of running by the torque of the power source, wherein (a) a target speed of the vehicle. (B) setting a target deceleration of the vehicle; (c) determining a last set target value of the target speed and the target deceleration; (E) controlling the power source to run at the target speed if the target speed is set last; and (e) controlling the target if the target deceleration is set last. Controlling the electric motor such that deceleration is performed at a deceleration.

According to such a control method, a plurality of acceleration setting steps are appropriately used properly and the electric vehicle is driven in a traveling state intended by the driver by the same operation as that described for the electric vehicle of the present invention. be able to.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples. (1) Configuration of device: FIG. 1 is a schematic configuration diagram of a hybrid vehicle as an embodiment. The power sources of the hybrid vehicle of this embodiment are the engine 10 and the motor 20. As shown in the figure, the power system of the hybrid vehicle according to the present embodiment includes:
As shown below, the engine 10 and the motor 2
0, the torque converter 30, and the transmission 100 are connected in series. Specifically, the motor 20
Is connected to the crankshaft 12 of the engine 10. The rotating shaft 13 of the motor 20 is
Tied to 0. The output shaft 14 of the torque converter is connected to the transmission 100. The output shaft 15 of the transmission 100 is connected to an axle 17 via a differential gear 16.

The engine 10 is a normal gasoline engine. However, the engine 10 sets the opening / closing timing of an intake valve for sucking a mixture of gasoline and air into the cylinder and an exhaust valve for discharging exhaust gas after combustion from the cylinder relative to the vertical movement of the piston. It has an adjustable mechanism (hereinafter, this mechanism is called a VVT mechanism). Since the configuration of the VVT mechanism is well known, a detailed description is omitted here. Engine 10
The so-called pumping loss can be reduced by adjusting the opening / closing timing so that each valve closes with a delay with respect to the vertical movement of the piston. As a result,
It is possible to reduce a braking force by a so-called engine brake. Further, the torque to be output from the motor 20 when the engine 10 is motored can be reduced. When power is output by burning gasoline, V
The VT mechanism is controlled such that each valve opens and closes at a timing with the highest combustion efficiency according to the rotation speed of the engine 10.

The motor 20 is a three-phase synchronous motor,
A rotor 22 having a plurality of permanent magnets on an outer peripheral surface and a stator 24 around which a three-phase coil for forming a rotating magnetic field is wound. The motor 20 is driven to rotate by interaction between a magnetic field generated by a permanent magnet provided on the rotor 22 and a magnetic field formed by a three-phase coil of the stator 24. When the rotor 22 is rotated by an external force, an interaction between these magnetic fields generates an electromotive force at both ends of the three-phase coil. The motor 20 includes the rotor 2
It is also possible to apply a sine wave magnetized motor in which the magnetic flux density between the stator 2 and the stator 24 has a sine distribution in the circumferential direction. A magnetic motor was applied.

The stator 24 is electrically connected to a battery 50 via a drive circuit 40. The drive circuit 40 is a transistor inverter, and is provided with a plurality of transistors for each of the three phases of the motor 20 by using two sets, one on the source side and the other on the sink side. As illustrated, the drive circuit 40 is electrically connected to the control unit 70. When the control unit 70 performs PWM control of the on / off time of each transistor of the drive circuit 40, a pseudo three-phase alternating current using the battery 50 as a power supply flows through the three-phase coil of the stator 24, and a rotating magnetic field is formed. The motor 20 functions as an electric motor or a generator as described above by the rotating magnetic field.

The torque converter 30 is a known power transmission mechanism using a fluid. The input shaft of the torque converter 30, that is, the output shaft 13 of the motor 20, and the output shaft 14 of the torque converter 30 are not mechanically coupled,
They can rotate with each other slipping. Turbines each having a plurality of blades are provided at both ends, and the turbine of the output shaft 13 of the motor 20 and the turbine of the output shaft 14 of the torque converter 30 are assembled inside the torque converter in a state where they face each other. ing. The torque converter 30 has a closed structure, and transmission oil is sealed therein. This oil acts on each of the aforementioned turbines,
Power can be transmitted from one rotating shaft to the other rotating shaft. In addition, since both can rotate in a slipping state, it is possible to convert the power input from one of the rotating shafts into a rotating state having a different number of rotations and a different torque and transmit the converted power to the other rotating shaft.

The transmission 100 includes a plurality of gears, clutches, one-way clutches, brakes, and the like, and converts the torque and the number of revolutions of the output shaft 14 of the torque converter 30 by switching the speed ratio, thereby converting the output shaft 15 to the output shaft 15. It is a mechanism that can transmit. FIG. 2 is an explanatory diagram showing the internal structure of the transmission 100. The transmission 100 of the present embodiment is mainly composed of an auxiliary transmission portion 110 (a portion on the left side of the broken line in the drawing) and a main transmission portion 120 (a portion on the right side of the broken line in the drawing). Thus, five forward speeds and one reverse speed can be realized.

The structure of the transmission 100 will be described in order from the rotating shaft 14 side. As shown in the figure, the power input from the rotating shaft 14 is transmitted to the rotating shaft 119 after being shifted at a predetermined gear ratio by a subtransmission unit 110 configured as an overdrive unit. The auxiliary transmission unit 110 is configured by a clutch C0, a one-way clutch F0, and a brake B0 centering on a single-pinion type first planetary gear 112. The first planetary gear 112 is a gear also referred to as a planetary gear, and includes three types of gears: a sun gear 114 that rotates at the center, a planetary pinion gear 115 that revolves while rotating around the sun gear, and a ring gear 118 that rotates around the outer periphery of the planetary pinion gear. It is composed of The planetary pinion gear 115 is supported by a rotating part called a planetary carrier 116.

In general, a planetary gear has such a property that when the rotational state of two of the above three gears is determined, the rotational state of the remaining one gear is determined. The rotation state of each gear of the planetary gear is given by a calculation formula (1) well-known in mechanics. Ns = (1 + ρ) / ρ × Nc−Nr / ρ; Nc = ρ / (1 + ρ) × Ns + Nr / (1 + ρ); Nr = (1 + ρ) Nc−ρNs; Ts = Tc × ρ / (1 + ρ) = ρTr; Tr = Tc / (1 + ρ); ρ = number of teeth of sun gear / number of teeth of ring gear (1);

Here, Ns is the rotation speed of the sun gear; Ts is the torque of the sun gear; Nc is the rotation speed of the planetary carrier; Tc is the torque of the planetary carrier; Nr is the rotation speed of the ring gear;

In the auxiliary transmission section 110, the rotating shaft 14 corresponding to the input shaft of the transmission 100 is connected to the planetary carrier 116. A one-way clutch F0 and a clutch C0 are arranged in parallel between the planetary carrier 116 and the sun gear 114. The one-way clutch F0 is provided in a direction in which the sun gear 114 is engaged when the sun gear 114 rotates forward relative to the planetary carrier 116, that is, when the sun gear 114 rotates in the same direction as the input shaft 14 to the transmission.
The sun gear 114 is provided with a multi-disc brake B0 that can stop the rotation. A ring gear 118 corresponding to the output of the subtransmission unit 110 is connected to the rotation shaft 119. The rotation shaft 119 corresponds to an input shaft of the main transmission unit 120.

In the subtransmission unit 110 having such a configuration, the planetary carrier 116 and the sun gear 114 rotate integrally when the clutch C0 or the one-way clutch F0 is engaged. According to the equation (1) shown above, when the rotation speeds of the sun gear 114 and the planetary carrier 116 are equal, the rotation speed of the ring gear 118 is also equal to them. At this time, the rotation shaft 119 is the input shaft 1
The number of rotations is the same as 4. Also, when the rotation of the sun gear 114 is stopped by engaging the brake B0, the rotation speed Nr of the ring gear 118 is apparent as a result of substituting a value 0 for the rotation speed Ns of the sun gear 114 in the above-described equation (1).
Is higher than the rotation speed Nc of the planetary carrier 116. That is, the rotation of the rotating shaft 14 is accelerated and the rotating shaft 119 is rotated.
Is transmitted to As described above, the auxiliary transmission unit 110 is
The power input from 4 is applied to the rotating shaft 11 as it is.
9 and the role of increasing the speed can be selectively performed.

Next, the configuration of the main transmission section 120 will be described.
The main transmission section 120 includes three sets of planetary gears 130 and 14.
0,150. Also, clutches C1, C2,
One-way clutches F1, F2 and brakes B1-B
4 is provided. Each of the planetary gears is
Similarly to the first planetary gear 112 provided in the first embodiment, a sun gear, a planetary carrier, a planetary pinion gear, and a ring gear are provided. The three planetary gears 130, 140, 150 are connected as follows.

Sun gear 1 of second planetary gear 130
32 and the sun gear 142 of the third planetary gear 140 are integrally connected to each other.
2 can be coupled to the input shaft 119. On the rotation shaft to which these sun gears 132 and 142 are connected,
A brake B1 for stopping the rotation is provided. Further, a one-way clutch F1 is provided in a direction in which the rotation shaft is engaged when the rotation shaft reversely rotates. Further, a brake B for stopping rotation of the one-way clutch F1
2 are provided.

The planetary carrier 134 of the second planetary gear 130 is provided with a brake B capable of stopping its rotation.
3 are provided. The ring gear 136 of the second planetary gear 130 is connected to the planetary carrier 144 of the third planetary gear 140 and the fourth planetary gear 15.
0 and the planetary carrier 154. Furthermore, these three are coupled to the output shaft 15 of the transmission 100.

The ring gear 146 of the third planetary gear 140 is connected to the sun gear 15 of the fourth planetary gear 150.
2 and to the rotating shaft 122. The rotation shaft 122 is connected to the main transmission unit 12 via the clutch C1.
0 can be coupled to the input shaft 119. The ring gear 156 of the fourth planetary gear 150 is provided with a brake B4 for stopping the rotation thereof and a one-way clutch F2 in a direction in which the ring gear 156 is engaged when the ring gear 156 reversely rotates.

The above-described clutches C0 to C2 and brakes B0 to B4 provided in the transmission 100 are engaged and released by hydraulic pressure, respectively. Although not shown, each clutch and brake is provided with a hydraulic pipe for enabling such an operation, a solenoid valve for controlling hydraulic pressure, and the like. In the hybrid vehicle of the present embodiment,
The control unit 70 controls the operation of each clutch and brake by outputting control signals to these solenoid valves and the like.

The transmission 100 of this embodiment has a clutch C0
C5 and the engagement and disengagement of the brakes B0 to B4 make it possible to set five forward speeds and one reverse speed. Also, so-called parking and neutral states can be realized. FIG. 3 is an explanatory diagram showing the relationship between the engagement state of each clutch, brake, and one-way clutch and the shift speed. In this figure, a mark ○ means that the clutch or the like is engaged, a mark 係 合 means that the clutch is engaged during power source braking,
The mark means that it engages but does not affect power transmission. The power source brake refers to braking by the engine 10 and the motor 20. The one-way clutch F
The engagement states of 0 to F2 are not based on the control signal of the control unit 70 but based on the rotation direction of each gear.

As shown in FIG. 3, in the case of parking (P) and neutral (N), the clutch C0 and the one-way clutch F0 are engaged. Since both the clutch C2 and the clutch C1 are in the disengaged state, the main transmission 1
No power is transmitted downstream from the 20 input shafts 119.

In the case of the first speed (1st), the clutch C
0, C1 and one-way clutches F0, F2 are engaged. When the engine brake is applied, the brake B4 is further engaged. In this state, the transmission 100
Is equivalent to a state in which the input shaft 14 of the fourth planetary gear 150 is directly connected to the sun gear 152 of the fourth planetary gear 150.
5 is transmitted. The ring gear 156 is restrained so as not to reverse by the action of the one-way clutch F2, and the number of rotations is practically zero. Under such conditions, according to the above-described equation (1), the rotation speed Nin and the torque Tin of the input shaft 14, the rotation speed Nout of the output shaft 15, and the torque Tou
The relationship with t is given by the following equation (2).

Nout = Nin / k1; Tout = k1 × Tink1 = (1 + ρ4) / ρ4; ρ4 is the speed ratio of the fourth planetary gear 150 (2);

In the case of the second speed (2nd), the clutch C
1. The brake B3 and the one-way clutch F0 are engaged. When the engine brake is applied, the clutch C0 is further engaged. In this state, the transmission 100
Is equivalent to a state where the input shaft 14 is directly connected to the sun gear 152 of the fourth planetary gear 150 and the ring gear 146 of the third planetary gear 140. On the other hand, the planetary carrier 134 of the second planetary gear 130 is in a fixed state. Second planetary gear 130 and third planetary gear
, The rotational speeds of the sun gears 132 and 142 are equal. Further, the rotation speeds of the ring gear 136 and the planetary carrier 144 are equal.
Under these conditions, in light of equation (1) described above,
The rotation state of the planetary gears 130 and 140 is uniquely determined. Rotational speed Nin of input shaft 14, torque Tin
And the relationship between the rotation speed Nout of the output shaft 15 and the torque Tout are given by the following equation (3). The rotation speed Nout of the output shaft 15 becomes higher than the rotation speed of the first speed (1st),
The torque Tout is lower than the first speed (1st) torque.

Nout = Nin / k2; Tout = k2 × Tink2 = {ρ2 (1 + ρ3) + ρ3} / ρ2; ρ2 is the speed ratio of the second planetary gear 130; ρ3 is the speed ratio of the third planetary gear 140 (3);

In the case of the third speed (3rd), the clutch C
0, C1, brake B2, one-way clutch F0, F
1 engage. When the engine brake is applied, the brake B1 is further engaged. In this state, the input shaft 14 of the transmission 100 is connected to the fourth planetary gear 150
Of the third planetary gear 140 and the ring gear 146 of the third planetary gear 140. On the other hand, the sun gears 132 and 142 of the second and third planetary gears 130 and 140 are in a state in which reverse rotation is prohibited by the action of the brake B2 and the one-way clutch F1, and the rotation speed is practically zero. Under these conditions, the second speed (2
As in the case of nd), according to the above-described equation (1), the rotational state of the planetary gears 130 and 140 is uniquely determined, and the rotational speed of the output shaft 15 is also uniquely determined. The relationship between the rotation speed Nin and the torque Tin of the input shaft 14 and the rotation speed Nout and the torque Tout of the output shaft 15 is as follows.
It is given by the following equation (4). Rotation speed Nout of output shaft 15
Becomes higher than the rotation speed of the second speed (2nd), and the torque T
out becomes lower than the torque of the second speed (2nd).

Nout = Nin / k3; Tout = k3 × Tin k3 = 1 + ρ3 (4);

In the case of the fourth speed (4th), the clutch C
0 to C2 and the one-way clutch F0 are engaged. The brake B2 is also engaged at the same time, but has nothing to do with the transmission of power. In this state, since the clutches C1 and C2 are simultaneously engaged, the input shaft 14 is connected to the second planetary gear 130.
, The sun gear 142 and the ring gear 146 of the third planetary gear 140, and the sun gear 152 of the fourth planetary gear 150.
As a result, the third planetary gear 140 rotates integrally with the input shaft 14 at the same rotation speed. Therefore, the output shaft 15 also integrally rotates at the same rotation speed as the input shaft 14. Therefore, in the fourth speed (4th), the output shaft 15 rotates at a higher rotation speed than in the third speed (3rd). That is, the rotation speed Nin and the torque Tin of the input shaft 14 and the rotation speed Nou of the output shaft 15
The relationship between t and the torque Tout is given by the following equation (5). The rotation speed Nout of the output shaft 15 is higher than the rotation speed of the third speed (3rd), and the torque Tout is increased to the third speed (3rd).
The torque becomes lower than d).

Nout = Nin / k4; Tout = k4 × Tin k4 = 1 (5);

In the case of the fifth speed (5th), the clutch C
1, C2 and brake B0 are engaged. The brake B2 is also engaged, but has nothing to do with power transmission. In this state, the clutch C0 is disengaged, and the rotation speed is increased by the subtransmission unit 110. That is, the input shaft 1 of the transmission 100
The rotation speed of the input shaft 11 of the main transmission unit 120 is increased
9 is transmitted. On the other hand, since the clutches C1 and C2 are simultaneously engaged, as in the case of the fourth speed (4th), the input shaft 1
19 and the output shaft 15 rotate at the same rotation speed. According to the above-described equation (1), the input shaft 14 of the subtransmission unit 110 is
And the rotation speed and torque of the output shaft 119, and the rotation speed and torque of the output shaft 15 can be obtained. The relationship between the rotation speed Nin and the torque Tin of the input shaft 14 and the rotation speed Nout and the torque Tout of the output shaft 15 is as follows.
It is given by the following equation (6). Rotation speed Nout of output shaft 15
Becomes higher than the rotation speed of the fourth speed (4th), and the torque T
out becomes lower than the torque of the fourth speed (4th).

Nout = Nin / k5; Tout = k5 × Tin k5 = 1 / (1 + ρ1) ρ1 is the speed ratio of the first planetary gear 112 (6);

In the case of reverse (R), the clutch C
2. The brakes B0 and B4 are engaged. At this time, the rotation speed of the input shaft 14 is increased by the
Is connected directly to the sun gear 132 of the planetary gear 130 and the sun gear 142 of the third planetary gear 140. As described above, the rotation speeds of the ring gear 136 and the planetary carriers 144 and 154 are equal. The rotation speeds of the ring gear 146 and the sun gear 152 also become equal.
Also, the ring gear 156 of the fourth planetary gear 150
Becomes zero due to the action of the brake B4. Under these conditions, according to the above-described equation (1), the rotational state of the planetary gears 130, 140, and 150 is uniquely determined. At this time, the output shaft 15 rotates in the negative direction,
Reverse is possible.

As described above, the transmission 1 of this embodiment
In the case of 00, five forward gears and one reverse gear can be realized. The power input from the input shaft 14 is output from the output shaft 15 as power having different rotation speed and torque.
The power output is from the first gear (1st) to the fifth gear (5t
The rotation speed increases in the order of h), and the torque decreases. This is the same when a negative torque, that is, a braking force is applied to the input shaft 14. The variables k1 to k5 in the above equations (2) to (6) represent the gear ratios of the respective gears. When a constant braking force is applied to the input shaft 14 by the engine 10 and the motor 20, the first speed (1st)
, The braking force applied to the output shaft 15 decreases in the order of the fifth speed (5th). As the transmission 100, various well-known configurations other than the configuration applied in the present embodiment can be applied. Either one where the shift speed is smaller than or larger than the fifth forward speed is applicable.

The transmission gear of the transmission 100 is controlled by the control unit 7.
0 is set according to the vehicle speed or the like. The driver can manually operate a shift lever provided in the vehicle to select a shift position, thereby changing a range of a shift speed to be used. FIG. 4 is an explanatory diagram showing the operation unit 160 of the shift position in the hybrid vehicle of the present embodiment. The operation unit 160 is provided on the floor next to the driver's seat in the vehicle along the front-rear direction of the vehicle.

As shown, a shift lever 162 is provided as the operation unit 160. The driver can select various shift positions by sliding the shift lever 162 back and forth. The shift positions are parking (P), reverse (R), neutral (N), drive position (D), fourth position (4), third position (3), second position (2) and low position from the front. They are arranged in the order of (L).

Parking (P), reverse (R), and neutral (N) correspond to the engaged state shown in FIG. 3, respectively. The drive position (D) means selection of a mode in which the vehicle travels using the first speed (1st) to the fifth speed (5th) shown in FIG. Hereinafter, the fourth position (4) is the third position (3) until the fourth speed (4th).
Is the third speed (3rd), the second position (2) is the second
Up to the speed (2nd) and the low position (L) mean the selection of a mode in which the vehicle runs using only the first speed (1st).

In the hybrid vehicle of this embodiment, the driver can arbitrarily set the braking force by the power source brake, that is, the deceleration of the vehicle, as described later. The operation unit 160 for selecting the shift position is also provided with a mechanism for setting the deceleration.

As shown in FIG. 4, the shift lever 162 in the hybrid vehicle of the present embodiment can be slid forward and backward to select a shift position, and can also be slid sideways at the drive (D) position. is there. The position selected in this manner is called an E position. When the shift lever 162 is in the E position, the setting of the braking force by the power source brake can be changed by operating the shift lever 162 back and forth as described below. The operation unit 16
At 0, a sensor for detecting the shift position and an E position switch which is turned on when the shift lever 162 is at the E position are provided. The signals of these sensors and switches are
The information is transmitted to the control unit 70 and used for various controls of the vehicle.

The operation when the shift lever 162 is at the E position will be described. The shift lever 162 is maintained at the neutral position of the E position when the driver releases his / her hand. When the driver wants to increase the deceleration, that is, when he / she wants to perform abrupt braking, the driver tilts the shift lever 162 backward (on the Decel side). To reduce the deceleration, that is, to perform gentle braking, the shift lever 1
Tilt 62 forward (Can-Decel side). In such a case, the shift lever 162 does not slide continuously in the front-rear direction, but moves with a sense of moderation. That is, the shift lever 162 adopts any one of three states: a neutral state, a state where it is tilted forward, and a state where it is tilted backward. When the driver reduces the force applied to the shift lever 162, the shift lever 162 immediately returns to the neutral position. The braking force of the power source brake changes stepwise according to the number of operations of the shift lever 162 in the front-rear direction.

In the hybrid vehicle of the present embodiment, in addition to the operation of the shift lever 162 described above, an operation section for changing the deceleration by the power source brake is provided on the steering wheel. FIG. 5 is an explanatory diagram illustrating an operation unit provided on the steering wheel. FIG. 5A shows the steering 164.
Is viewed from the side facing the driver, that is, from the front. As shown in the figure, a Decel switch 166L for increasing the deceleration in the spoke portion of the steering 164,
166R are provided. These switches are provided at a location where the driver can easily operate the steering wheel with his right or left thumb. In the present embodiment, the two switches provided on the front surface are unified to have the same function so that an appropriate operation can be performed without confusion even when the steering wheel is rotated.

FIG. 5B shows a state in which the steering wheel 164 is viewed from the back. As shown in the figure, at the place almost corresponding to the back side of the Decel switches 166L and 166R,
Can-Decel switch 1 for reducing deceleration
68L and 168R are provided. These switches are provided at locations where the driver can easily operate the steering wheel with the right or left index finger.
For the same reason as the Decel switches 166L and 166R, both switches are unified to have the same function.

When the driver operates the Decel switch 166L, 1
When 66R is pressed, the deceleration increases according to the number of presses.
When the Can-Decel switches 168L and 168R are pressed, the deceleration is reduced according to the number of times. These switches 166L, 166R, 168L, 168R
Is valid only when the shift lever 162 is in the E position (see FIG. 4). With such a configuration, it is possible to prevent the driver from unintentionally operating these switches when operating the steering wheel 164 and changing the setting of the target braking force.

The operation unit 160 is further provided with a snow mode switch 163. The snow mode switch 163 is operated by the driver when the road surface has a low coefficient of friction such as a snowy road and slips easily.
When the snow mode switch 163 is on, the upper limit value of the target braking force is suppressed to a predetermined value or less, as described later. If the vehicle is decelerated with a large braking force while traveling on a road surface having a low friction coefficient, slipping may occur. When the snow mode switch 163 is on, the braking force is suppressed to a predetermined value or less, so that a slip can be avoided. of course,
When the snow mode switch 163 is turned on, it is possible to change the deceleration within a range where slip does not occur.

The operation unit 160 also has an auto cruise switch 169 for specifying on / off of auto cruise.
Is provided. When the auto cruise switch 169 is turned on, the vehicle runs at the vehicle speed at the time when the switch was turned on even if the driver depresses the accelerator pedal. However, when the inter-vehicle distance to the vehicle in front approaches the predetermined distance or less, the vehicle is automatically decelerated so as to widen the inter-vehicle distance. In order to realize such control, the hybrid vehicle of this embodiment is equipped with a vehicle speed sensor 171 and a headway sensor 170 as shown in FIG. In this embodiment,
As the inter-vehicle sensor 170, a laser distance measuring device provided at the tip of the vehicle is used. As the inter-vehicle sensor 170, various other sensors using ultrasonic waves, radio waves, and the like can be applied.

The operation section for selecting the shift position and setting the target braking force can employ various configurations other than the configuration shown in this embodiment (FIG. 4). FIG. 6 is an explanatory diagram illustrating an operation unit 160A according to a modification. The operation unit 160A is provided along the front-back direction of the vehicle beside the driver. The driver can select various shift positions by sliding the shift lever 162 forward and backward. In FIG. 6, only the drive position (D) is shown and four positions and the like are omitted, but various shift positions can be provided similarly to the operation unit 160 in FIG. Operation unit 160 of modified example
In A, an E position is provided further behind a normal movable range for selecting a shift position. The driver can continuously change the setting of the deceleration by sliding the shift lever 162 in the forward / backward direction within the E position. In this example, the deceleration is increased by sliding the shift lever 162 backward, and the deceleration is reduced by sliding the shift lever 162 forward. Note that this modification is merely an example, and various other configurations can be applied to the mechanism for setting the deceleration.

The deceleration setting described above is displayed on the dashboard in the vehicle. FIG. 7 is an explanatory diagram illustrating an instrument panel of the hybrid vehicle according to the present embodiment. This instrument panel
Like a normal vehicle, it is installed in front of the driver. The instrument panel is provided with a fuel gauge 202 and a speedometer 204 on the left side as viewed from the driver, and an engine water temperature gauge 20 on the right side.
8. An engine tachometer 206 is provided. A shift position indicator 220 for displaying a shift position is provided at the center, and direction indicator indicators 210L and 210R are provided on the left and right sides thereof. These are display units equivalent to a normal vehicle. In the hybrid vehicle of the present embodiment, an E position indicator 222 is provided above the shift position indicator 220 in addition to these display units. Further, a deceleration indicator 224 for displaying the set deceleration is provided on the right side of the E position indicator 222.

The E position indicator 222 lights when the shift lever is at the E position. When the driver operates the Decel switch and the Can-Decel switch to set the deceleration, the deceleration indicator 224 changes the length of the backward arrow (rightward arrow in FIG. 7) provided along with the vehicle symbol. The setting result is intuitively displayed by increasing or decreasing. As described later, the hybrid vehicle according to the present embodiment may suppress the deceleration set based on various conditions. The E position indicator 222 and the deceleration indicator 224
When such suppression is performed, a display in an unusual manner such as a blinking display is performed to also serve to notify the driver of the suppression of deceleration.

In the hybrid vehicle of this embodiment, the engine 10, the motor 20, the torque converter 30, and the transmission 1
1 is controlled by the control unit 70 (see FIG. 1).
reference). The control unit 70 includes a CPU, a RAM,
This is a one-chip microcomputer including a ROM and the like, and a CPU performs various control processes described later according to a program recorded in the ROM. Various input / output signals are connected to the control unit 70 to realize such control. FIG. 8 is an explanatory diagram showing connection of input / output signals to the control unit 70. A signal input to the control unit 70 is shown on the left side of the drawing, and a signal output from the control unit 70 is shown on the right side.

The signals input to the control unit 70 are signals from various switches and sensors. Such a signal includes, for example, a hybrid cancel switch that instructs operation using only the engine 10 as a power source, an acceleration sensor that detects the acceleration of the vehicle, the number of revolutions of the engine 10,
The water temperature of the engine 10, the ignition switch, the remaining capacity SOC of the battery 50, the crank position of the engine 10,
Defogger on / off, air conditioner operating state, vehicle speed detected by vehicle speed sensor 171, torque converter 3
0 oil temperature, shift position (see FIG. 4), side brake on / off, foot brake depression amount, temperature of catalyst for purifying exhaust of engine 10, accelerator opening,
Auto cruise switch on / off, E position switch on / off (see FIG. 4), Decel switch for changing setting of target braking force, and Can-Decel
There are a switch, a headway detected by the headway sensor 170, a turbine speed of a turbocharger, a snow mode switch for instructing a running mode on a road surface having a low friction coefficient such as a snowy road, a fuel lid signal from a fuel gauge, and the like.

The signal output from the control unit 70 is
These are signals for controlling the engine 10, the motor 20, the torque convertor 30, the transmission 100, and the like. Such signals include, for example, an ignition signal for controlling the ignition timing of the engine 10, a fuel injection signal for controlling the fuel injection, a starter signal for starting the engine 10, and switching of the drive circuit 40 to operate the motor 20. MG control signal to control,
A transmission control signal for switching the gear position of the transmission 100, an AT solenoid signal and an AT line pressure control solenoid signal for controlling a hydraulic pressure of the transmission 100, a signal for controlling an actuator of an antilock brake system (ABS), a driving force Drive power source indicator signal indicating the power source, air conditioner control signal, control signal for preventing various alarm sounds, control signal of electronic throttle valve of engine 10, snow mode indicator signal indicating selection of snow mode, engine There are a VVT signal for controlling the opening / closing timing of the ten intake valves and exhaust valves, a system indicator signal for displaying the operating state of the vehicle, and a set deceleration indicator signal for displaying the set deceleration.

(2) General Operation: Next, the general operation of the hybrid vehicle of this embodiment will be described. Figure 1
As described above, the hybrid vehicle of the present embodiment includes the engine 10 and the motor 20 as power sources. The control unit 70 uses both of them according to the traveling state of the vehicle, that is, the vehicle speed and the torque. The use of both is set in advance as a map, and the ROM in the control unit 70 is used.
Is stored in

FIG. 9 is an explanatory diagram showing the relationship between the running state of the vehicle and the power source. The curve LIM in the figure indicates the limit of the area in which the vehicle can travel. A region MG in the figure is a region where the vehicle runs with the motor 20 as the power source, and a region EG is a region where the vehicle runs with the engine 10 as the power source. Hereinafter, the former is referred to as EV traveling, and the latter is referred to as normal traveling. According to the configuration of FIG.
Although it is possible to run with both of the power sources 0 as the power source, such a running region is not provided in the present embodiment.

As shown in the figure, the hybrid vehicle according to the present embodiment starts with EV running. As described above (see FIG. 1), the hybrid vehicle of the present embodiment has the engine 1
0 and the motor 20 are configured to rotate integrally. Therefore, the engine 10 is also rotating during the EV traveling. However, the motoring is being performed without performing fuel injection and ignition. As described above, the engine 10 includes the VVT mechanism. Control unit 7
0 indicates the opening / closing timing of the intake valve and the exhaust valve by controlling the VVT mechanism in order to reduce the load applied to the motor 20 during EV running and to use the power output from the motor 20 effectively for running the vehicle. Delay.

Control unit 70 starts engine 10 when the vehicle started by EV running reaches the running state near the boundary between area MG and area EG in the map of FIG. Since the engine 10 has already been rotated at a predetermined rotation speed by the motor 20, the control unit 70 injects fuel into the engine 10 at a predetermined timing and ignites it.
Further, the VVT mechanism is controlled to change the opening / closing timing of the intake valve and the exhaust valve to a timing suitable for the operation of the engine 10.

After the engine 10 is started in this way, the vehicle runs in the region EG using only the engine 10 as a power source. When traveling in such an area is started, the control unit 70 shuts down all the transistors of the drive circuit 40. As a result, the motor 20 simply turns idle.

The control unit 70 performs the control of switching the power source according to the running state of the vehicle as described above, and also performs the process of switching the gear position of the transmission 100. The switching of the shift speed is performed based on a map set in advance in the running state of the vehicle, similarly to the switching of the power source. FIG.
0 is a map showing the relationship between the gear position of the transmission 100 and the running state of the vehicle. As shown in this map, the control unit 70 executes the switching of the gear stage so that the gear ratio decreases as the vehicle speed increases.

This switching is restricted by the shift position. In the drive position (D), as shown in FIG. 10, the vehicle travels using the speed up to the fifth speed (5th). In the four positions, the vehicle travels using gears up to the fourth speed (4th). In this case, 5 in FIG.
The fourth speed (4th) is used even in the th region.
In addition to the switching based on this map, the shift speed is switched by so-called kick down, in which the driver shifts the shift speed to a higher one-speed ratio by rapidly depressing an accelerator pedal. These switching controls are the same as in a known vehicle using an engine alone as a power source and having an automatic transmission. In the present embodiment, the same switching is performed when the vehicle is traveling in the EV mode (the area MG). Note that the relationship between the shift speed and the traveling state of the vehicle is shown in FIG.
In addition to the above, various settings can be made according to the gear ratio of the transmission 100.

FIGS. 9 and 10 show maps in the case where EV traveling and normal traveling are selectively used according to the traveling state of the vehicle. The control unit 70 of the present embodiment is also provided with a map in a case where all traveling states are performed in normal traveling. Such a map is shown in FIG. 9 and FIG.
This excludes the traveling region (region MG). E
In order to perform the V running, it is necessary that a certain amount of power is stored in the battery 50. Therefore, the control unit 70 switches the map according to the state of charge of the battery 50, and controls the vehicle. That is, the battery 5
When the remaining capacity SOC of 0 is equal to or more than the predetermined value, the operation is performed by selectively using the EV traveling and the normal traveling based on FIGS. 9 and 10. When the state of charge SOC of the battery 50 is smaller than a predetermined value, the vehicle is driven in normal traveling using only the engine 10 as a power source even during starting and traveling at a low speed. 2 above
Use of one map is repeatedly determined at predetermined intervals. Therefore, even when the remaining capacity SOC is equal to or more than the predetermined value and the vehicle starts to start in EV traveling, if the remaining capacity SOC becomes smaller than the predetermined value as a result of the power consumption after the start, the running state of the vehicle falls within the area MG. Even if there is, it can be switched to normal running.

Next, braking of the hybrid vehicle of this embodiment will be described. The hybrid vehicle according to the present embodiment can be braked by two types of brakes: a wheel brake added by depressing a brake pedal, and a power source brake by load torque from the engine 10 and the motor 20. The braking by the power source brake is performed when the accelerator pedal is depressed. The power source brake changes according to the vehicle speed.

In the hybrid vehicle of the present embodiment, the driver can change the braking force of the power source brake stepwise by operating at the E position described above. E
When the Decel switch is operated in the position,
The power source brake gradually increases. Can-Dece
Operating the 1 switch gradually weakens the power source brake.

The hybrid vehicle according to the present embodiment is realized by controlling the power source brake set in a stepwise manner in such a manner as to combine both the switching of the shift speed of the transmission 100 and the braking force by the motor 20. FIG.
FIG. 4 is an explanatory diagram showing a map of a combination of a vehicle speed, a deceleration, and a shift speed in the hybrid vehicle of the embodiment. In FIG. 11, the deceleration is indicated by an absolute value. By operating the Decel switch and the Can-Decel switch, the deceleration of the vehicle is reduced by a straight line B in FIG.
It changes stepwise in the range of L to BU.

The braking force by the power source brake is
By controlling the torque of 0, it can be changed within a certain range. Further, by switching the gear position of the transmission 100, the ratio between the torque of the power source and the torque output to the axle 17 can be changed, so that the deceleration of the vehicle can be changed according to the gear position. . As a result, when the speed is in the second speed (2nd), the deceleration in the range indicated by the short broken line in FIG. 11 can be achieved by controlling the torque of the motor 20. 3rd speed (3rd)
, The deceleration in the range shown by the solid line in FIG. 11 can be achieved. When the vehicle is in the fourth speed (4th), the deceleration in the range indicated by the one-dot chain line in FIG. 11 can be achieved. When the vehicle is in the fifth speed (5th), FIG.
The deceleration in the range indicated by the long broken line in FIG. 1 can be achieved.

The control unit 70 selects a shift speed that achieves the deceleration set in accordance with the map shown in FIG. 11 and performs braking. For example, when the deceleration is set to the straight line BL in FIG. 11, in a region where the vehicle speed is higher than the value VC, the fifth
Braking is performed at the speed (5th), and in the region where the vehicle speed is lower than the value VC, the gear is switched to the fourth speed (4th) to perform braking. In such a region, the desired deceleration cannot be realized at the fifth speed (5th). In the present embodiment, the ranges of the deceleration realized at each shift speed are set to overlap. In a region where the vehicle speed is higher than the value VC, the deceleration corresponding to the straight line BL can be realized in both the fourth speed (4th) and the fifth speed (5th). Therefore, in such a region, the control unit 70 selects one of the fourth speed (4th) and the fifth speed (5th), based on various conditions, and performs a braking operation by selecting a gear that is more suitable for braking.

The setting of the shift speed in this embodiment will be described in more detail. FIG. 12 is an explanatory diagram showing the relationship between the braking force and the shift speed at a certain vehicle speed Vs. This corresponds to the relationship between the braking force and the shift speed along the straight line Vs in FIG. As shown in FIG. 12, the section D1 where the deceleration is relatively small
Thus, the braking force is realized only in the fifth speed (5th). In the section D2 where the deceleration is larger than the fifth speed (5t
h) and the fourth speed (4th) realizes the braking force. Similarly, as the braking force sequentially increases, only the fourth speed (4th) in the section D3, the third speed (3rd) or the fourth speed (4th) in the section D4, and the third speed (3rd) in the section D5.
Only in the section D6, the second speed (2nd) or the third speed (3
rd), in the section D7, the respective braking forces are realized only in the second speed (2nd). Here, the second speed (2n
Although the map using d) is shown, braking using the first speed (L) may be performed.

The reason why the decelerations at the respective gears overlap will be described. FIG. 13 is an explanatory diagram showing deceleration at the second speed (2nd). The broken line TL in the figure indicates the lower limit of the deceleration realized in the second speed (2nd), and the broken line TU
Indicates the upper limit. The straight line TE indicates the deceleration realized only by the engine brake by the engine 10.
In the hybrid vehicle of the present embodiment, it is possible to change the deceleration by the engine brake by controlling the VVT mechanism. However, such control has low response and accuracy. Therefore, in the present embodiment, when braking, V
Not controlling the VT mechanism. As a result, as shown in FIG. 13, the deceleration due to the engine brake is a value uniquely determined according to the vehicle speed.

In this embodiment, the deceleration is changed by controlling the torque of the motor 20. FIG.
In the hatched region Bg, the motor 20 performs a so-called regenerative operation, and a braking force is also applied to the motor 20 to realize a deceleration larger than the deceleration due to the engine brake. The other area Bp, that is, the straight line T
In the region between E and the broken line TL, the motor 20 is driven in a power mode, and a driving force is output from the motor 20, thereby achieving a deceleration lower than that of the engine brake.

FIG. 14 is an explanatory diagram schematically showing the relationship between the braking torque when the motor 20 is in the regenerative operation and the braking torque when the motor 20 is in the power running operation. On the left side of the figure, the braking torque (state in the region Bp) when the motor 20 is operated in power running is shown. The braking torque by the engine brake is indicated by a belt BE in the figure. Region Bp
Then, the motor 20 outputs the driving force indicated by the band BM in the direction opposite to the braking torque by the engine brake.
Since a braking torque consisting of the sum of the two is output to the axle 17, a braking torque lower than the braking torque BE by the engine brake is output as shown by hatching in the figure.

The right side of the figure shows the braking torque (state in the region Bg) when the motor 20 is regeneratively operated. The braking torque by the engine brake is indicated by a band BE having the same size as that in the region Bp. Area B
At p, the motor 20 outputs the braking torque indicated by the band BM in the same direction as the braking torque by the engine brake. Since a braking torque consisting of the sum of the two is output to the axle 17, a braking torque larger than the braking torque BE by the engine brake is output as shown by hatching in the figure.

As described above, in the hybrid vehicle of the present embodiment, by switching the operation state of the motor 20 between the regenerative operation and the power running operation, the deceleration larger than the deceleration by the engine brake and the lower deceleration are realized. .
Then, for example, the region of the deceleration realized by the power running operation at the gear stage on the side of the higher gear ratio and the region of the deceleration realized by the regenerative operation at the gear stage of the lower gear ratio overlap each other. The map of FIG. 11 is set. For example, an area of braking by power running at the second speed (2nd) and an area of braking by regenerative operation at the third speed (3rd) are overlapped.

By setting as described above, braking can be performed in a mode suitable for the remaining capacity SOC of battery 50. For example, when the battery 50 is in a state where it can be further charged, a gear position with a smaller gear ratio is selected so that a desired deceleration can be obtained by the regenerative operation of the motor 20. When the battery 50 is almost fully charged,
The gear position with the larger gear ratio is selected so that the desired deceleration is obtained by the power running operation of the motor 20. In the present embodiment, as described above, the ranges of the deceleration by the two shift speeds are set in an overlapping manner, so that the battery 5
The desired deceleration can be realized regardless of the remaining capacity SOC of zero.

Needless to say, these settings are merely examples, and the decelerations realized by the respective gears may be set so as not to overlap. In addition, instead of setting all the shift speeds to have an area that overlaps with the other shift speeds as in the map of FIG. 11, a setting may be made so that only some of the shift speeds have an overlap area.

On the other hand, when the auto cruise switch 169 is turned on, the control unit 70 sets an appropriate acceleration based on the vehicle speed and the distance between vehicles. When the vehicle needs to be decelerated, the straight lines BL to B in the map of FIG.
The deceleration is set in the range of U. The deceleration in this case is E
Unlike the setting of the deceleration in the position, the straight line BL to B
U is set in a continuous range. The control unit executes the selection of the gear ratio and the control of the engine and the electric motor with reference to the map of FIG. 11 as in the case of the E position. A map similar to that in FIG. 11 is prepared for the positive acceleration, and the control unit selects a gear ratio based on the map,
Executes control of the engine and electric motor.

In this embodiment, braking at the set deceleration is realized by various methods. However, such control is performed when the above-described E position or auto cruise is on (hereinafter, such braking is referred to as deceleration control braking). When these conditions are not satisfied, that is, when the shift lever is not at the E position and the auto cruise is off, normal braking is performed. In normal braking, unlike the deceleration control braking, the shift speed is not switched. Therefore, braking is performed with the gear position used when the power source brake is applied. When the vehicle is in the drive position (D), the vehicle normally travels at the fifth speed (5th), so that the braking is performed with a relatively low braking force that can be realized at the shift speed. When the vehicle is in the fourth position (4), the vehicle travels up to the fourth speed (4th), so that braking at a deceleration slightly larger than the drive position (D) is realized. At the time of normal braking, the braking force of the motor 20 is also in a regenerative operation in which a constant load is applied. Therefore, a wide range of deceleration cannot be realized at each shift speed as in the map shown in FIG. 11, and only one deceleration indicated by one straight line can be realized at each shift speed.

(3) Operation control processing: In the hybrid vehicle of this embodiment, the control unit 70 controls the engine 10, the motor 20, and the like, thereby enabling the above-described traveling. Hereinafter, the details of the deceleration control will be described focusing on the driving at the time of braking characteristic of the hybrid vehicle of the present embodiment.

FIG. 15 is a flowchart of a deceleration control processing routine. This processing is performed by the CP of the control unit 70.
U is a process executed in a predetermined cycle. When this process is started, the CPU first performs a function determination process (step S10). The hybrid vehicle of the present embodiment has two types of functions for setting the deceleration: the E position and the auto cruise. The function judgment process means that auto cruise is
This is a process of determining the selection status of the OFF and E positions and determining which function should be enabled.

FIG. 16 is a flowchart of a function determination processing routine. In the function determination processing routine, the CPU first inputs a switch signal (step S15). The signals to be input here are listed in FIG. Of course, signals directly related to the function determination processing routine include a signal indicating a shift position, a signal of an E position switch, and a signal indicating ON / OFF of an auto cruise switch 169. Therefore, in step S15, only these signals may be input.

Next, the CPU determines whether or not the shift position has been switched from the D position to the E position based on the input signal (step S).
20). If the input shift position is the E position and the previous shift position is the D position, it is determined that the above-described switching has been performed.
The determination may be made based on whether or not the E position switch has changed from the off state to the on state.

When the switching from the D position to the E position is performed, a process for inhibiting the auto cruise is performed (step S25). In this embodiment, the value of an auto cruise flag for indicating whether or not auto cruise can be executed is set to 0. At the same time, a process of permitting the setting of the deceleration is performed (step S25).
In this embodiment, the deceleration setting flag for indicating whether the deceleration can be set is set to a value of 1. Next, CPU
Turns on the E position indicator (see FIG. 7) (step S30). A signal for turning on the E position indicator is output as the system indicator signal shown in FIG. The E position indicator is turned on in response to this signal. At the same time as the lighting of the E position indicator, the CPU sets the set value to a value corresponding to the D position to initialize the target braking force (step S35).

At the time of the D position, the fifth speed (5t
If the vehicle is traveling in h), in step S60, the target braking force corresponding to the deceleration realized at this shift speed is set as an initial value. In this embodiment,
As shown in FIG. 11, in the low vehicle speed region, the lowest value of the set deceleration (the straight line BL in the figure) is the fifth speed (5t).
It may be larger than the deceleration realized in h). Although not explicitly shown in the flowchart, the setting of the target braking force in step S60 is performed within the range of the deceleration that can be taken at the E position. Therefore, when the deceleration realized at the D position is lower than the minimum deceleration (the straight line BL) that can be taken at the E position, the deceleration is set to a value corresponding to the straight line BL. As a result, depending on the gear position used at the D position, the initial setting value of the deceleration becomes a value equivalent to the deceleration realized at the D position in a region where the vehicle speed is relatively high, and a D value in a region where the vehicle speed is relatively low. In some cases, the deceleration is larger than the deceleration realized in the position.

If it is determined in step S20 that the switching is not from the D position to the E position, the CPU determines whether or not an operation of turning on the auto cruise switch 169 has been performed (step S4).
0). It is not determined whether or not the auto cruise switch 169 is continuously turned on, but it is determined whether or not an operation has been performed. That is, when the signal indicating the on / off state of the auto cruise switch is switched from the off state to the on state, it is determined that the on operation has been performed. When the operation of turning on the auto cruise switch is performed, a process of permitting the auto cruise function is performed. That is, a process of setting the flag indicating whether auto cruise is possible to a value of 1 is performed.

If the operation of turning on the auto cruise switch has not been performed, the CPU determines whether or not the switching from the E position to the D position has been performed (step S30). That is, if the input shift position is the D position and the previous shift position is the E position, the above-described switching has been performed. The determination may be made based on whether or not the E position switch has changed from the on state to the off state. If the operation of turning on the auto cruise switch has been performed, the above determination is skipped.

If either of the conditions in step S25 or step S30 is satisfied, the CPU turns off the E position indicator (see FIG. 7) (step S30).
35). That is, a signal for turning off the E position indicator is output in addition to the system indicator signal shown in FIG. The E position indicator is turned off in response to this signal. At the same time that the E position indicator is turned off, the CPU releases the set value of the target braking force (step S40). While traveling in the E position, the driver operates the Decel switch and the Can-Dece
By operating the 1 switch, a desired deceleration is set. In step S40, all such settings are released.

Further, a process for prohibiting the setting of the deceleration is executed (step S45). In the present embodiment, the deceleration setting flag is set to the value 0. When such processing is performed, even if the E position is selected, De
The setting of the deceleration by operating the cel switch and the Can-Decel switch is prohibited. If both step S25 and step S30 are not satisfied, the processing of steps S35 to S45 is skipped.

As described above, the shift lever 162
When an effective function is selected according to the operation of the automatic cruise switch 169 and the operation of the auto cruise switch 169, the CPU ends the function determination processing routine. Upon completion of the function determination processing routine, the CPU returns to the deceleration control processing routine, and then executes deceleration setting processing (step S100). This process is a process for setting the deceleration to be realized at the E position based on the operation of the Decel switch and the Can-Decel switch. The contents of the deceleration setting process will be described with reference to FIG.

FIG. 17 is a flowchart of a deceleration setting processing routine. When this process is started, the CPU inputs a switch signal (step S105). The signal input here is D out of various signals shown in FIG.
These are signals of an ecel switch, a Can-Decel switch, an E position switch, and a snow mode switch. Of course, other signals may be input together.

Next, the CPU determines whether setting of deceleration by the driver is permitted (step S11).
0). This determination is made based on the value of the deceleration setting flag. If the flag is value 1, it is determined that setting of deceleration is permitted. If the flag is value 0,
It is determined that the setting of the deceleration is prohibited. If it is determined that the setting of the deceleration is prohibited, it is determined that the change of the setting of the deceleration should not be accepted, and the CPU
Terminates the deceleration setting processing routine without performing any processing.

If it is determined in step S110 that the setting of the deceleration is permitted, the CPU next proceeds to De.
It is determined whether the cel switch and the Can-Decel switch have failed (step S115). The failure can be determined by various methods. For example, when a switch is in poor contact, so-called chattering occurs,
Switching on and off is detected very frequently. On at a frequency higher than a specified value for a specified time
When off is detected, it can be determined that the switch has failed. Conversely, a failure can be determined even when the switch is on for a long time that cannot be expected in normal operation.

If a switch failure is detected, the CPU cancels the setting of the target braking force in order to avoid setting the deceleration unintended by the driver (step S).
170). Processing that does not change the setting of the target braking force may be performed. In the present embodiment, it is assumed that the switch breaks down while the driver is correcting the deceleration set to a value not in accordance with the driver's intention, and the setting of the target braking force is released. After releasing the setting of the target braking force, the CPU performs a failure display for notifying the driver of the failure of the switch (step S175). Various methods can be used for the failure display. In the present embodiment, an alarm sound and an E position indicator (FIG. 7)
(See Reference). These notifications are shown in FIG.
This is realized by outputting signals corresponding to the alarm sound signal and the system indicator signal shown in FIG.

The CPU further performs processing for prohibiting deceleration control braking (step S180). In this embodiment, as a prohibition process, the CPU turns on a prohibition flag provided for prohibiting deceleration control braking. As will be described later, when the actual braking control is performed, the deceleration control braking is prohibited or permitted by turning on / off the prohibition flag. When deceleration control braking is prohibited, braking corresponding to the D position is performed regardless of whether the shift lever is at the E position. If the switch has failed, the CPU executes the above processing and ends the deceleration setting processing routine.

If it is determined in step S115 that the switch has not failed, the CPU proceeds to a process for changing the setting of the target braking force. As such processing, first, the CPU executes the Decel switch and the Can-
It is determined whether or not the Decel switches are simultaneously operated (step S120). If both switches are operated at the same time, it is not clear which switch should be given priority. Therefore, the following process for changing the setting of the target braking force is skipped, and the current setting is maintained.

As shown in FIGS. 4 and 5, in the hybrid vehicle of this embodiment, the target braking force can be set by using both the shift lever and the switch provided on the steering wheel. Therefore, due to the driver's erroneous operation,
The switch of the shift lever and the switch of the steering unit may be operated at the same time. Also, a Decel switch and a Can-De provided in the steering unit are provided.
Both of the cel switches may be operated simultaneously. In particular, such an erroneous operation is highly likely to be performed by the driver without intention of changing the deceleration, for example, when the steering is operated for steering. In the present embodiment, the reason why the setting of the target braking force is maintained when both the Decel switch and the Can-Decel switch are simultaneously operated is that the setting of the target braking force is changed by an erroneous operation that does not follow the driver's intention. The intention is to avoid this.

Decel switch and Can-Dec
If it is determined that both el switches are not operated at the same time, the setting of the target braking force is changed according to the operation of each switch. That is, when it is determined that the Decel switch is turned on (step S12).
5), the CPU increases the setting of the target braking force (step S130). If it is determined that the Can-Decel switch is turned on (step S135), C
The PU reduces the setting of the target braking force (Step S14)
0). In the present embodiment, the setting of the target braking force is changed stepwise according to the number of times each switch is operated. When none of the switches is operated, the setting of the target braking force is, of course, not changed.

The above processing (steps S120 to S140)
When the target braking force is set, the CPU determines whether the set deceleration is within the reject range (step S145). In this embodiment, the upper limit of the deceleration is changed according to the on / off state of the snow mode switch (see FIG. 8). The snow mode switch is a switch operated by a driver when the vehicle is running on a road surface having a low friction coefficient such as a snowy road. If sudden braking is performed while traveling on a road surface having a low friction coefficient, the vehicle may slip. When the driver turns on the snow mode switch, the upper limit value of the deceleration is suppressed to such an extent that the slip of the vehicle can be avoided.

If the set deceleration exceeds the above upper limit, it is determined that the deceleration is within the reject range. If it is determined that the deceleration is within the reject range, the CPU
Suppresses the set deceleration to an allowable upper limit (step S150). Further, a process for notifying the driver that the setting of the target braking force has been suppressed is performed (step S155). In this embodiment, the deceleration indicator 224 blinks for about one second. In addition, a warning sound is emitted in conjunction with this. These notifications are realized by outputting appropriate signals for the alarm sound and the control signal of the set deceleration indicator shown in FIG. If it is determined in step S145 that the set deceleration is not within the reject range, these processes are skipped. When the deceleration is set by the above processing, the CPU displays the result on the deceleration indicator 224 (step S160), and ends the deceleration setting processing routine.

The above processing (steps S120 to S140)
FIG. 18 shows how the setting of the target braking force is changed by the
21 will be described based on the specific example of FIG. FIG.
5 is a time chart showing a setting example of FIG. Time is plotted on the horizontal axis, the operation of the Decel switch and the Can-Decel switch, the change of the set value of the target target braking force, the change of the torque of the motor 20 and the change of the gear position for achieving the set deceleration. Are shown in the figures. FIG. 18 illustrates that the vehicle speed is constant.

At time a1, it is assumed that the Decel switch is turned on. Although not specified in the flowchart of FIG. 17, in the present embodiment, it is assumed that the setting change is accepted only when the switch is continuously turned on for a predetermined time or more. That is, in step S105 of the deceleration setting processing routine (FIG. 17), the CPU inputs the operation result of the switch based on the determination whether or not the switch is continuously on for a predetermined time or more. . Generally, a switch is turned on and off with a very short cycle when switching on and off due to a phenomenon called chattering.
Normally, the OFF signal is detected alternately. If the setting is changed after the elapse of the predetermined time, it is possible to prevent the deceleration from largely changing against the driver's intention due to chattering.

Further, by accepting the switch input only after being operated for a predetermined time, it is possible to prevent the driver from unintentionally touching the switch and changing the setting of the target braking force. In particular, in the present embodiment, since the Decel switch and the Can-Decel switch are provided in the steering unit, there is a high possibility that the driver accidentally touches the switch. Therefore, means for avoiding a change in the setting of the target braking force due to an accidental operation is particularly effective.

The above-described predetermined time (hereinafter, referred to as an ON determination reference time) can be set as a reference for determining whether the driver has intentionally operated the switch. If the ON determination reference time is short, there is a high possibility that the setting of the target braking force is changed by an accidental operation of the driver.
Conversely, if the ON determination reference time is long, the responsiveness of the Decel switch and the Can-Decel switch deteriorates. The ON determination reference time can be set to an appropriate value by experiment or the like in consideration of these conditions.
Of course, the driver may be able to set a value suitable for the driver.

In the example of FIG. 18, the time from time a1 to time a2 exceeds the above-described ON determination reference time. Therefore, the deceleration set at time a2 increases by one step.
As described with reference to FIG. 11, in the present embodiment, by controlling both the shift speed and the torque of the motor in combination, it is possible to realize an arbitrary deceleration in a wide range. FIG.
As is clear from FIG. 7, the range of the deceleration greatly changes by switching the gear, and can be finely changed by controlling the motor torque. In the present embodiment, the set deceleration is changed stepwise within a relatively fine range. The steps changed at the time point a2 in FIG.
As shown in the figure, this is a range of steps that can be changed by changing the motor torque without changing the gear position. Note that the case where the fifth speed (5th) is the initial value has been described as an example of the shift speed.

Next, when the Decel switch is turned on beyond the ON determination reference time between times a3 and a4, the set deceleration further increases by one step as shown in the figure. In the present embodiment, as shown in the figure, the second change of the deceleration is realized by changing the torque of the motor without switching the gear. As described above, in this embodiment, the deceleration steps are set in small steps. By doing so, the selection range in which the setting of the target braking force can be changed is widened without switching the gear position, so that the driver can easily set the deceleration suited to his own requirements. Therefore, as shown in FIG.
, But the speed is maintained at the fifth speed (5th).

In this embodiment, as a condition for accepting the operation of the switch, an operation interval reference time relating to an interval when the switch is continuously operated is set in addition to the ON determination reference time. That is, when the switch is continuously operated, the subsequent operation is accepted as valid only when the subsequent operation is performed after the first operation and after the above-described operation interval reference time has elapsed. In step S105 of the deceleration setting processing routine (FIG. 17), the CPU determines whether or not the operation interval reference time has elapsed since the previous operation, and then inputs the switch operation. .

For example, in FIG. 18, times a5 to a6
As a third operation, the Decel switch is operated. The operation time exceeds the ON determination reference time. However, the operation here is performed at time a4 after the previous operation.
Only a small amount of time corresponding to 〜a5 has elapsed. In this embodiment, this time is shorter than the operation interval reference time. Therefore, the third operation is not accepted as a valid operation, even though the operation has been performed for a time longer than the ON determination reference time, and none of the setting of the target target braking force, the motor torque, and the gear position change.

By setting the operation interval reference time in this way, it is possible to prevent the setting of the target braking force from being excessively suddenly changed based on the driver's operation. When the driver changes the deceleration, a predetermined time delay usually occurs until the deceleration is actually performed at the deceleration. However, without setting the operation interval reference time,
When a change in the setting of the target braking force is received, the setting of the target braking force may be changed one after another without checking the deceleration achieved by the setting. As a result, the deceleration may be changed more rapidly than the driver's intention. In this embodiment, such a situation is avoided by providing the operation interval reference time.

The operation interval reference time can be set by an experiment or the like so as to satisfy the intention. If the operation interval reference time is short, the change in the setting of the target braking force cannot be made sufficiently gradual. Conversely, if the operation interval reference time is long, it takes a long time to change the setting of the target braking force, and the operability decreases. The operation interval reference time can be set to an appropriate value by experiments or the like in consideration of these conditions. Of course, the driver may be able to set a value suitable for the driver.

In the example of FIG. 18, the Decel switch is operated between times a7 and a8 as the fourth operation. This operation time exceeds the ON determination reference time.
Therefore, the deceleration set according to the fourth operation further increases. This means that the deceleration is increased by three steps from the reference deceleration before operating the Decel switch. In the present embodiment, the setting is such that such deceleration cannot be realized only by controlling the torque of the motor. Therefore, at the time of the fourth operation, the shift speed is changed to the fifth speed (5t) according to the increase in the set deceleration.
h) to the fourth speed (4th). The shift speed is switched based on the map of FIG. 11 as described above. By switching the shift speed to the fourth speed, the range of achievable decelerations is widened as a whole. Therefore,
In the fourth operation, the motor torque is reduced in order to achieve a deceleration three steps higher than the reference deceleration. The torque of the motor is set based on the set deceleration and gear set according to the map of FIG.

It should be noted that switching the gear position in accordance with the increase in deceleration is not only for achieving the required deceleration,
It also has the advantage of achieving rapid acceleration. Generally, after braking at a large deceleration, rapid acceleration is often required to return to the vehicle speed before braking. If the gear stage is switched to a side where the gear ratio is higher with an increase in the deceleration, rapid acceleration can be performed using the gear stage after braking. Therefore, the responsiveness of the vehicle at the time of acceleration / deceleration can be improved by switching the shift speed according to the set deceleration.

Although the operation for increasing the deceleration has been described above, the same applies to the operation for decreasing the deceleration. As shown in FIG. 18, at times a9 to a10, 5
The Can-Decel switch is operated as the second operation. The operation time exceeds the ON determination reference time. Accordingly, the deceleration set according to this operation is reduced by one step, and becomes equal to the deceleration set at time a4. In order to achieve this deceleration, the gear position and the torque of the motor are simultaneously changed.

Next, at times a11 to a12, the Can-Decel switch is operated as the sixth operation. This operation time is shorter than the ON determination reference time. Therefore, this operation is determined to be invalid, and none of the set deceleration, motor torque, and shift speed change.
Although not illustrated in FIG. 18, if the operation interval of the Can-Decel switch is shorter than the operation interval reference time, the operation is similarly determined to be invalid, and the set deceleration and the like do not change.

Next, a second setting example of the set deceleration will be described. FIG. 19 is a time chart showing the second setting example. As illustrated, it is assumed that the Decel switch has been operated between times b1 and b2. It is assumed that the operation time exceeds the ON determination reference time described above. As described in the first setting example, the deceleration set according to the operation increases by one step. In addition, the torque of the motor is increased so as to realize the deceleration.

Next, it is assumed that the Decel switch is operated as the second operation between times b3 and b6. It is assumed that the ON determination reference time described above has been exceeded.
However, in this case, along with the operation of the Decel switch, the Can-Decel switch is also operated between times b4 and b6. The time from time b3 when the operation of the Decel switch is started to time b4 when the operation of the Can-Decel switch is started is shorter than the ON determination reference time. Therefore, at the time point b4 when the operation of the Can-Decel switch is started, Decece
The operation of the l switch is not accepted as valid.

As described above in the deceleration setting processing routine, when the Decel switch and the Can-Decel switch are simultaneously operated, the CPU of the control unit 70 does not change the setting of the target braking force (FIG. 17). See step S120). Therefore, as shown in FIG.
In spite of the fact that the Decel switch has been operated between 3 and b5 beyond the ON determination reference time, none of the set deceleration, motor torque, and gear position change. In FIG. 19, the time during which only the Decel switch is operated (between times b3 and b4) and the time when Can-De
Time during which only the cel switch is operated (time b5
This is because none of (b6) does not exceed the ON determination reference time. For example, when the time between the times b3 and b4 exceeds the ON determination reference time, the deceleration set by operating the Decel switch increases by one step. If the period between times b5 and b6 exceeds the ON determination reference time, the deceleration set by operating the Can-Decel switch is reduced by one step.

Next, when the Decel switch is operated beyond the ON determination reference time between times b7 and b8 as the third operation after an interval longer than the operation interval reference time, the switch operation becomes effective. Accepted as
The setting of the target braking force increases by one step. At the same time, the torque of the motor increases.

In the second operation, the case where the operation of the Can-Decel switch is performed after the operation of the Decel switch is started has been described. The same reason that the setting of the target braking force does not change when both switches are operated at the same time is the same as when the Can-Decel switch is operated first. As shown in FIG. 19, the Can-Decel switch is operated as the fourth operation between times b9 and b11. In conjunction with this operation, times b10 to b12
The Decel switch is operated during the period. Time b1
Between 0 and b11, both switches are operated simultaneously. In this case as well, none of the set deceleration, motor torque, and gear position change, as described in the second operation.

Decel switch and Can-Decel
If the switch and the switch are operated at the same time, there is a high possibility that the driver has performed an erroneous operation. As specifically shown in FIG. 19, when both switches are simultaneously operated, the setting of the target braking force is maintained, so that the deceleration is prevented from being changed against the driver's intention due to an erroneous operation. can do. In addition, by doing so, it is also possible to suppress frequent changes in the setting of the target target braking force due to the operation timing of the Decel switch and the Can-Decel switch.

In the first and second setting examples (FIGS. 18 and 19), the case where the set deceleration changes stepwise according to the number of operations of the Decel switch and the Can-Decel switch. If the target braking force is set in this manner, a modest setting can be achieved. Further, since the target braking force changes stepwise, the target braking force can be changed widely by an operation in a relatively short time, and there is an advantage that the operability is excellent. On the other hand, the setting of the target braking force may be configured to change continuously according to the operation time of the switch. An example in which the setting of the target braking force changes according to the operation time is shown in FIG. 20 as a third setting example.

In this example, as the first operation, time c
The Decel switch is operated between 1 and c3.
As in the first and second setting examples, the operation of the switch is accepted as valid when the ON determination reference time has elapsed. In the example of FIG. 20, the interval between times c1 and c2 corresponds to the ON determination reference time. Time c in the first operation
Between 2 and c3, the set deceleration increases in proportion to the operation time of the Decel switch. Further, in order to realize the set deceleration, the torque of the motor also changes at the same time.

As the second operation, when the Decel switch is operated between times c4 and c6, after the time c5 when the ON determination reference time has elapsed from the start of the operation, the Decece switch is operated.
The deceleration set according to the operation time of the 1 switch increases. In addition, the torque of the motor changes accordingly.
In the third setting example, since the deceleration set by the first and second operations can be realized by changing the torque of the motor, the gear position does not change. When the set deceleration has changed to such an extent that it cannot be realized only by a change in the torque of the motor, the shift speed is switched based on the map in FIG.

Thereafter, as the third operation, the time c7
The Decel switch is operated during c8. However, the interval from time c6 when the second operation is completed to time c7 when the third operation is started is shorter than the operation interval reference time. Therefore, similar to the first and second setting examples,
The third operation is not accepted as valid, and the set deceleration does not change.

As a fourth operation, the Decel switch is operated between times c9 and c10. This operation time is shorter than the ON determination reference time. Therefore, the fourth operation is not accepted as valid, and the set deceleration does not change.

In the third setting example, not only the side for increasing the set deceleration but also the side for decreasing the deceleration are Can-Decel.
The setting changes according to the operation time of the switch. Time c1
As the fifth operation between 1 and c13, Can-Dece
When the 1 switch is operated, the set deceleration decreases in proportion to the switch operation time after time c12 when the ON determination reference time has elapsed.

Thereafter, as the sixth operation, time c14
The Can-Decel switch is operated during c15. This operation time is shorter than the ON determination reference time.
Therefore, the sixth operation is not accepted as valid, and the set deceleration does not change.

Assuming that the set deceleration changes continuously according to the operation time of the switch as in the third setting example, the driver can reduce the desired deceleration without repeatedly operating the switch. There is an advantage that speed can be obtained. Further, since the target braking force changes continuously, there is an advantage that the target braking force can be set precisely according to the driver's intention. In addition,
In the third setting example, the set deceleration changes in proportion to the operation time of the switch. However, the deceleration set non-linearly with respect to the operation time may be changed. For example, the set deceleration may change relatively slowly at the beginning of the operation, and the set deceleration may change quickly as the operation time increases.

Next, FIG. 21 shows an example in which the deceleration set as the fourth setting example falls within the reject range. In the fourth setting example, as the first operation, times d1 to d3
The Decel switch has been operated before this. At time d2 when the ON determination reference time has elapsed from the start of the operation, the operation of the Decel switch is accepted as valid, and the set deceleration increases by one step. At the same time, the torque of the motor increases.

Similarly, when the Decel switch is operated between times d4 and d6 as the second operation, similarly, at time d5 when the ON determination reference time has elapsed, Decel is performed.
The operation of the switch is accepted as valid, and the set deceleration increases by one step. At the same time, the torque of the motor increases.

Similarly, when the Decel switch is operated between times d7 and d9 as the third operation,
At time d8 when the ON determination reference time has elapsed, Dec
The operation of the el switch is accepted as valid,
The set deceleration increases. When the set upper limit of the deceleration is not limited, the set deceleration is increased by one step as shown by a dashed line in FIG. In this case, similarly to the first setting example (FIG. 18), the torque of the motor and the shift speed also change.

In the fourth setting example, the upper limit of the deceleration is set to DC
lim. When the deceleration set in the third operation is changed to a value indicated by a dashed line, the set deceleration exceeds the upper limit value DClim. In such a case, the set deceleration is within the reject range, and therefore, as described above (FIG. 17).
, The set deceleration is suppressed to the upper limit value DClim, and becomes the value indicated by the solid line in FIG. At the same time, the torque of the motor and the shift speed also become the set values indicated by the solid lines. In FIG. 21, the torque of the motor is increased as compared to before the suppression, and the speed is changed to the fifth speed (5
th) is maintained, but these are the results of setting according to the map of FIG. 11 so as to realize the deceleration DClim. The gear position and the torque of the motor are not necessarily in such a relationship as before the suppression.

As shown in the above specific examples, the hybrid vehicle of this embodiment has a Decel switch and a Can-
By operating the Decel switch, the driver can set various set decelerations. Also,
Unintentional or frequent operation by the driver unintentionally,
A change in the deceleration can be suppressed.

When the deceleration setting processing is completed, the CPU returns to the deceleration control processing routine (FIG. 15) and executes the auto cruise setting processing (step S170). FIG.
It is a flowchart of an auto cruise setting process. When this process is started, the CPU determines whether the setting of the auto cruise is permitted (step S17).
2). This determination is made by turning on / off the auto cruise flag. If the value of the flag is 1, it is determined that the setting is permitted. If the value of the flag is 0, it is determined that the setting is prohibited. If it is determined that the setting is prohibited, the CPU ends the auto cruise setting processing routine without performing any processing.

If it is determined that the setting is permitted, the CPU executes processing for setting a target acceleration based on the vehicle speed and the distance between vehicles. For this purpose, first, the vehicle speed and the following distance are detected (step S174). These are detected by a vehicle speed sensor 171 and a headway sensor 170, respectively.

Next, the CPU determines whether or not the headway is smaller than a predetermined reference value LL (step S176). If the distance between vehicles is smaller than the reference value LL, the vehicle needs to be decelerated in order to avoid the danger caused by too close a distance between vehicles. Therefore, in such a case, the CPU sets the deceleration according to the following distance as the target deceleration (step S178). In this embodiment, a table in which the target deceleration is set in advance according to the inter-vehicle distance at each vehicle speed is stored in the ROM in the control unit. Step S
At 178, the target deceleration is set by referring to this table. The reference value LL is a value serving as a reference as to whether or not to perform deceleration for preventing the vehicle from getting too close to each other, and an appropriate value can be set in advance by experiment or analysis. The reference value LL may be different depending on the vehicle speed.

If it is determined in step S176 that the headway is equal to or greater than the reference value LL, the CPU executes a control for maintaining the target vehicle speed V * as an auto cruise function. In the present embodiment, the target acceleration AC is set by so-called PID control based on the deviation ΔV between the current vehicle speed V and the target vehicle speed V * (step S18).
0). That is, the target acceleration AC is set by the following equation (7). AC = k1.DELTA.V + k2.SIGMA. (. DELTA.V) + k3.d (.DELTA.V) / dt; .DELTA.V = V * -v; (7) where d (.DELTA.V) / dt means the time derivative of .DELTA.V.

As shown in the above equation (7), the target acceleration AC
Is obtained from a proportional term (first term on the right side), an integral term (second term), and a differential term (third term) of the speed deviation ΔV. k1,
k2 and k3 are gains, and appropriate values can be set by experiment or analysis so that desired responsiveness and stability are realized. Since PID control is a well-known technique, further detailed description will be omitted.

As a result of the calculation, the vehicle speed V becomes equal to the target vehicle speed V
If it is higher than *, braking will be performed at the target acceleration AC. Conversely, when the vehicle speed V is lower than the target vehicle speed V *, acceleration is performed at a predetermined acceleration. Both are obtained by the above equation (7). In the former case, the target acceleration AC has a negative value, and in the latter case, the target acceleration AC has a positive value. When the target acceleration is set according to the following distance and the vehicle speed by the above processing, the CPU ends the auto cruise setting processing routine and returns to the deceleration control processing routine (FIG. 15).

Next, in the deceleration control processing routine, the CPU
Determines whether a condition for braking is satisfied (step S200). The conditions for performing the braking are determined as follows based on the result of the function determination process (step S10) and the set acceleration value. First, if Auto Cruise is selected as a valid feature,
That is, the case where the value of the auto cruise flag is 1 will be described. In this case, the auto cruise setting process is performed regardless of the accelerator pedal depression amount (step S1).
If the acceleration set in 70) is a negative value, that is, a value at which the vehicle should be decelerated, it is determined that the condition for performing the braking is satisfied.

Next, a case where the auto cruise is not selected as a valid function, that is, a case where the value of the auto cruise flag is 0 will be described. Such cases include both the case where the E position is selected as valid and the case where auto cruise is off. In such a case, it is determined that the condition for performing braking when the accelerator pedal is off is satisfied. In step S200,
When it is determined that the condition for performing the braking is not satisfied, the CPU ends the deceleration control processing routine without performing any processing.

If the condition for braking is satisfied, the CPU determines whether or not the deceleration control braking is permitted (step S205). As described above in the deceleration setting processing routine (FIG. 17), when the switch is out of order, the prohibition flag for prohibiting deceleration control braking is turned on (step S180 in FIG. 17). . If this flag is on, it is determined that deceleration control braking is not permitted.
In addition, even when the auto cruise is off and the shift lever is not at the E position, it is determined that deceleration control braking is not permitted.

If it is determined in step S205 that the deceleration control braking is not permitted, C
The PU sets the target torque of the motor 20 to a predetermined negative value Tm0 as the normal braking process (Step S210).
The predetermined value Tm0 can be set to any value within the range of the rating of the motor 20. In the present embodiment, in the D position, the value is set to such a value that a sufficient or sufficient braking force can be obtained by the power source brake.

On the other hand, if it is determined in step S205 that deceleration control braking is permitted, the CPU executes deceleration control braking processing. Specifically, first, a gear change process is performed (step S21).
5).

FIG. 23 is a flowchart of the gear position switching process. In the speed change process, the CPU first refers to the map shown in FIG. 11 (step S22).
0). Next, the CPU refers to the map in accordance with the set deceleration, and determines whether or not there are two or more shift speeds capable of achieving the set deceleration (step S22).
6). If there is only one gear position that achieves the set deceleration, the gear position is determined to be the gear position determined from the map (step S228).

If it is determined that there are two shift speeds that achieve the set deceleration, the remaining capacity SO of the battery 50 is determined.
Referring to C, it is determined whether or not the SOC is equal to or greater than a predetermined value HL (step S230). As described above with reference to FIG. 13, in each shift speed, there is a deceleration realized by regenerating the motor 20 and a deceleration realized by powering the motor 20. When the two speeds correspond to the set deceleration, the deceleration set by the regenerative operation of the motor 20 is realized at one speed, and the power running operation of the motor 20 at the other speed. The set deceleration is realized. Therefore, when two gears correspond to the set deceleration, an appropriate gear can be selected according to the remaining capacity SOC of the battery 50.

When the remaining capacity SOC is equal to or higher than the predetermined value H, it is desirable to consume power in order to avoid overcharging of the battery 50. Accordingly, the CPU selects the gear position on the side that realizes the set deceleration by the power running operation of the motor 20, that is, the gear position with the larger gear ratio among the two gear positions (step S232). When the remaining capacity SOC is smaller than the predetermined value H, it is desirable to charge the battery 50. Accordingly, the CPU selects the gear position on the side that realizes the set deceleration by regenerative operation of the motor 20, that is, the gear position on the smaller gear ratio side of the two gear positions (step S234). Of course, it is preferable to provide a predetermined hysteresis for the determination in step S230 in order to prevent the selection of the two shift speeds from frequently switching according to the remaining capacity SOC.

When the gear to be used is set by the above processing, the CPU switches the gear (step S236). To switch the gear, a predetermined signal is output to the transmission control signal (see FIG. 8) to control the on / off of the clutch and the brake of the transmission 100 according to the gear set as shown in FIG. It is realized by doing.

When the change of the gear position is completed,
The CPU returns to the deceleration control processing routine and calculates a target value of the torque to be output by the motor 20 (step S25).
0). If the gear ratios k1 to k5 previously shown in the equations (2) to (6) are used in accordance with the shift speed, the engine 10 is set based on the set deceleration, that is, the torque output to the axle 17.
And the total torque to be output from the power source of the motor 20 can be calculated. Braking force output from the engine 10,
The so-called engine brake is almost uniquely determined according to the rotation speed of the crankshaft 12. Therefore, the torque to be output by the motor 20 can be obtained by subtracting the torque from the engine brake from the total torque output from the power source.

In the present embodiment, the target torque of the motor 20 is obtained by the calculation as described above.
In addition to the map described above, a map that gives the target torque of the motor 20 may be prepared. Alternatively, the deceleration of the vehicle may be detected by an acceleration sensor, and the torque of the motor 20 may be feedback-controlled so that the set deceleration is realized. In the flowchart of FIG. 15, for convenience of illustration, the motor torque is calculated after the shift speed switching process is completed. However, the motor torque may be calculated in parallel with the switching process. is there.

By the above processing, the target torque of the motor is set according to each of the normal braking processing and the E-position braking processing. The CPU executes a braking control process (step S2).
As 50), the control of the operation of the motor 20 and the operation of the engine 10 are executed. The control of the engine 10 is a control for applying the engine brake, and the CPU makes the injection of the fuel to the engine 10 correspond to the idling operation. Although the control of the VVT mechanism provided in the engine 10 can be performed at the same time, in this embodiment, the braking force of the power source brake can be controlled by the torque of the motor 20.
No control of the VVT mechanism is performed.

[0167] The motor 20 is operated by so-called PWM control. The CPU sets a voltage value to be applied to the coil of the stator 24. Such a voltage value is given according to the rotation speed of the motor 20 and the target torque based on a table set in advance. When the motor 20 performs the regenerative operation, the voltage value is set as a negative value, and when the motor 20 performs the power running operation, the voltage value is set as a positive value. The CPU controls ON / OFF of each transistor of the drive circuit 40 so that the voltage is applied to the coil. Since the PWM control is a well-known technique, further detailed description will be omitted.

By repeatedly executing the deceleration control processing routine described above, the hybrid vehicle of this embodiment can perform braking by the power source brake.
Of course, it goes without saying that braking by the wheel brake can be performed in conjunction with such braking.

FIG. 24 shows how the deceleration changes in the hybrid vehicle of this embodiment. FIG. 24 is an explanatory diagram showing how the target deceleration is changed by operating the auto cruise switch, the shift position, and the Decel switch. As illustrated, it is assumed that the E position is initially selected. It is also assumed that the auto cruise switch has been turned off.

In such a state, FIGS.
As indicated by 0, the driver can operate the Decel switch to change the target deceleration stepwise. That is, the first operation s for the Decel switch
At time e1 when t1 is performed, the target deceleration is changed from the reference value to a value DC1 which is higher by one step. Second operation st
2 is performed, at time e2, the target deceleration is changed to DC2, which is one step higher.

Here, it is assumed that the auto cruise switch is turned on at time e3. The shift position remains at the E position. As shown in the function determination processing routine (FIG. 16), when the auto cruise switch is turned on, the setting is canceled even if the E position is selected, and the target deceleration is set by the auto cruise function. As a result, as shown in FIG. 24, the deceleration is set to a value DA determined according to the following distance and the vehicle speed.
In this state, since all functions at the E position are prohibited, the third operation of the Decel switch is performed.
Even if t3 is executed, the setting of the target deceleration is not changed.
Here, the deceleration due to the auto cruise is shown as a constant value of the value DA, but actually the deceleration fluctuates every moment according to the vehicle speed and the distance between vehicles.

Next, when the shift position is once returned to the D position at time e4 and the E position is selected again, the function is prohibited even if the auto cruise switch is turned on, and the function at the E position is prohibited. The function is selected as valid. The deceleration setting by the operations st1 and st2 for the Decel switch has been released. Therefore, at time e4, the target deceleration becomes the reference deceleration at the E position. When the driver performs the fifth operation st5 on the Decel switch in this state, the target deceleration is set to a value DC1 that is one step higher than the reference deceleration, as in the case of the first operation st1.

In the present embodiment, after returning to the D position once and selecting the E position again,
It is assumed that the function in the position will be effective, but D
The function at the E position may be enabled by operating the ecel switch. In such a case, after the auto cruise function is enabled, Decel
The setting of the target deceleration is changed when the third operation st3 of the switch is performed.

In this embodiment, the system last operated by the driver is selected as the effective system from the two systems of the E position and the auto cruise. When there are two systems involved in the running state of the vehicle, the driver is likely to request that the last system operated works effectively. In the hybrid vehicle according to the present embodiment, by selecting the last operated system as a valid one, it is possible to realize a driving with almost no uncomfortable feeling for the driver, and to improve the operability and the drive feeling of the vehicle. be able to.

Further, in the hybrid vehicle of the present embodiment,
For the two systems, E-position and Auto Cruise, there is no need to cancel the other when selecting one. Therefore, comfortable driving can be realized with less burden on the operation of the driver.

In this embodiment, the engine 10 and the motor 20
Are directly connected to each other and connected to the axle 17 via the transmission 100. The present invention is applicable to a parallel hybrid vehicle having various other configurations, that is, a hybrid vehicle capable of directly transmitting output from an engine to an axle. Further, the present invention can be applied to a series hybrid vehicle in which power from an engine is used only for power generation and is not directly transmitted to a drive shaft.

FIG. 25 is an explanatory diagram showing the configuration of such a series hybrid vehicle. As shown in the figure, in this hybrid vehicle, a motor 20A as a power source is connected to an axle 1 via a torque converter 30A and a transmission 100A.
7A. The engine 10A and the generator G are connected. Engine 10A is not connected to axle 17A. The motor 20A is connected to a battery 50A via a drive circuit 40A. The generator G is connected to the battery 50A via the drive circuit 41. The drive circuits 40A and 41 are the same transistor inverters as in this embodiment. These operations are controlled by the control unit 70A.

In a series hybrid vehicle having such a configuration, the motive power output from engine 10A is converted to electric power by generator G. This power is supplied by the battery 50A
And is used to drive the motor 20A. The vehicle can run with the power of the motor 20A. If a negative torque is output from the motor 20A as a braking force, the power source brake can be applied. Since this hybrid vehicle also includes the transmission 100A, by controlling the combination of the torque of the motor 20A and the shift speed, the braking force set by the driver in a wide range can be reduced, similarly to the hybrid vehicle of the present embodiment. Can be realized.

In the hybrid vehicle of this embodiment, the axle 1
7, the target torque of the motor 20 was set by subtracting the braking torque by the engine brake from the total torque to be output. On the other hand, in the hybrid vehicle of the modified example, since the braking force by the engine brake has a value of 0, the braking torque to be output to the axle 17A may be set as the target torque of the motor 20A.

The present invention is also applicable to a pure electric vehicle using only an electric motor as a power source. The configuration of such an electric vehicle corresponds to a configuration in which the engine 10A, the generator G, and the drive circuit 41 are removed from the series hybrid vehicle of FIG. Even in the case of a pure electric vehicle, by controlling the torque and the shift speed of the motor 20A coupled to the axle, the control set by the driver in a wide range as in the case of the series hybrid vehicle and the hybrid vehicle of the present embodiment. Power can be realized.

In the above-described embodiment, a case has been described in which a transmission capable of changing the gear ratio stepwise is applied. In contrast,
A transmission that can continuously change the gear ratio may be applied.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and may be implemented in various other forms without departing from the gist of the present invention. Obviously you can get it.
The various control processes described in the present embodiment may be realized by hardware. In addition, only some of the various control processes described in the present embodiment may be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hybrid vehicle as an embodiment.

FIG. 2 is an explanatory diagram showing an internal structure of the transmission 100.

FIG. 3 is an explanatory diagram showing a relationship between engagement states of clutches, brakes, and one-way clutches and shift speeds.

FIG. 4 is an explanatory diagram showing an operation unit 160 of a shift position in the hybrid vehicle of the embodiment.

FIG. 5 is an explanatory diagram showing an operation unit provided on a steering.

FIG. 6 is an explanatory diagram showing an operation unit 160A according to a modified example.

FIG. 7 is an explanatory diagram showing an instrument panel of the hybrid vehicle in the embodiment.

8 is an explanatory diagram showing connection of input / output signals to a control unit 70. FIG.

FIG. 9 is an explanatory diagram showing a relationship between a traveling state of a vehicle and a power source.

FIG. 10 is an explanatory diagram showing a relationship between a gear position of the transmission 100 and a traveling state of the vehicle.

FIG. 11 is an explanatory diagram showing a map of a combination of a vehicle speed, a deceleration, and a shift speed in the hybrid vehicle of the embodiment.

FIG. 12 is an explanatory diagram showing a relationship between a braking force and a shift speed at a vehicle speed Vs.

FIG. 13 is an explanatory diagram showing deceleration when the gear position is fixed.

FIG. 14 is an explanatory diagram schematically showing a relationship between a braking torque when the motor 20 performs the regenerative operation and a braking torque when the motor 20 performs the power running operation.

FIG. 15 is a flowchart of a deceleration control processing routine.

FIG. 16 is a flowchart of a function determination processing routine.

FIG. 17 is a flowchart of a deceleration setting processing routine.

FIG. 18 is a time chart showing a first setting example of deceleration.

FIG. 19 is a time chart illustrating a second setting example of deceleration.

FIG. 20 is a time chart showing a third setting example of deceleration.

FIG. 21 is a time chart showing a fourth setting example of deceleration.

FIG. 22 is a flowchart of an auto cruise setting processing routine.

FIG. 23 is a flowchart of a gear shift processing routine;

FIG. 24 is an explanatory diagram showing how the target deceleration is changed by operating the auto cruise switch, the shift position, and the Decel switch.

FIG. 25 is an explanatory diagram showing a configuration of a series hybrid vehicle.

[Explanation of symbols]

 10, 10A ... engine 12 ... crankshaft 13, 14, 15 ... output shaft 16 ... differential gear 17, 17A ... axle 20, 20A ... motor 22 ... rotor 24 ... stator 30, 30A ... torque converter 40, 40A, 41 ... drive Circuits 50, 50A Battery 70, 70A Control unit 100, 100A Transmission 110 Sub-transmission unit 112 First planetary gear 114 Sun gear 115 Planetary pinion gear 116 Planetary carrier 118 Ring gear 119 Output shaft 120 Main Transmission section 122 ... Rotary shaft 130 ... Planetary gear 130 ... Second planetary gear 132 ... Sun gear 134 ... Planetary carrier 136 ... Ring gear 140 ... Third planetary gear 142 ... Sun gear 144 ... Planetary carry 146 ... ring gear 150 ... fourth planetary gear 152 ... sun gear 154 ... planetary carrier 156 ... ring gear 160, 160A ... operating section 162 ... shift lever 163 ... snow mode switch 164 ... steering 166L, 166R, 168L, 168R ... switch 169 ... auto cruise Switch 170: Inter-vehicle sensor 171: Vehicle speed sensor 202: Fuel gauge 204: Speedometer 206: Engine tachometer 208: Engine water temperature gauge 210L, 210R: Direction indicator indicator 220: Shift position indicator 224: Deceleration indicator

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[Procedure amendment]

[Submission date] February 19, 1999 (Feb.
9)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60L 11/12 F02D 29/02 D F02D 29/00 301D 29/02 341 301 29/06 D 341 B60K 9 / 00Z 29/06 (72) Inventor Seishi Nakamura 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Masaya Amano 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term ( Reference) 3D041 AA33 AA41 AA80 AB00 AC01 AC18 AD01 AD31 AD51 AE02 AE03 AE31 AE45 AF01 3D044 AA04 AA35 AB00 AC02 AC22 AC26 AC28 AC59 AD01 AD02 AD17 AE01 AE04 AE07 AE12 AE19 AE21 3A09 DBA11 DBA11 DB23 EA15 EB00 EB03 EC02 FA07 FA10 FA11 FA13 FB05 FB06 5H115 PG04 PI16 PI24 PI29 PO17 PU10 PU23 PU24 PU25 PU26 PV09 PV23 QE0 9 QE10 QI04 QI09 QI12 QI15 QN03 QN12 RB08 RB22 SE04 SE05 SE08 SJ12 SJ13 TB01 TE02 TE08 TI02 TO02 TO05 TO21 TO23 TZ07

Claims (4)

[Claims] 1. An electric vehicle having an axle coupled to a power source including at least an electric motor and capable of running by a torque of the power source, a target speed setting means for setting a target speed of the vehicle, Speed control means for controlling the power source so as to run at a target speed; target deceleration setting means for setting a target deceleration of the vehicle; and the electric motor so that deceleration is performed at the set target deceleration. Controlling the deceleration control means, and selectively executing the speed control means and the deceleration control means in accordance with the last one of the target speed setting means and the target deceleration setting means for which the target value is set. Electric vehicle comprising: 2. The electric vehicle according to claim 1, wherein the power source is an electric motor and an engine. 3. The electric vehicle according to claim 1, wherein a transmission capable of changing a plurality of gear ratios is coupled to the power source and the axle, and further comprising: controlling the target acceleration by a torque of the power source. An electric vehicle including a speed ratio selection unit that selects a feasible speed ratio. 4. A method for controlling an electric vehicle having an axle coupled to a power source including at least an electric motor and capable of traveling by a torque of the power source, the method comprising: (a) setting a target speed of the vehicle; (B) setting a target deceleration of the vehicle; (c) determining a last set target value of the target speed and the target deceleration;
(D) controlling the power source to run at the target speed when the target speed is set last; and (e) when the target deceleration is set last. Controlling the electric motor such that deceleration is performed at the target deceleration.