Constant speed traveling control system for vehicle

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a constant speed travel control system for a vehicle that causes a vehicle to travel at a constant speed at a set speed.

【0002】

[Conventional technology]

In recent years, many vehicles are equipped with a constant-speed running control system that automatically runs the vehicle at a constant speed at a speed set by the driver. Further, with the electronic control of the vehicle control unit, the development of a device in which the control unit of the constant speed running control system is built in the arithmetic processing means mounted on the vehicle controller is being developed. If constant-speed driving is set, it is not necessary to keep pressing the accelerator pedal, so that the burden on the driver is reduced, especially when traveling a long distance using a highway.

【0003】

As the constant speed driving control system, for example, in a gasoline engine vehicle, the vehicle speed measured by the vehicle speed sensor is compared with the set speed set by the driver, and the throttle valve opening of the engine is controlled to perform constant speed driving. It is known that this is done. In order to prevent the vehicle speed from changing due to the influence of the increase or decrease in the traveling resistance such as the slope of the road, the road surface condition and the wind, generally, the vehicle speed at the time when the constant speed traveling switch is pressed is stored as the set speed. At predetermined time intervals, the throttle valve opening degree is finely adjusted to keep the traveling vehicle speed constant as compared with the measured traveling vehicle speed, and the vehicle travels at a constant speed.

【0004】

[Problems to be Solved by the Invention]

However, it is difficult to accurately control the engine output determined by the fuel injection amount of the engine, the intake air flow rate in the cylinder, and the like by controlling the throttle valve opening degree in this way. Further, since the engine output is changed frequently, there is a problem that the fuel consumption is poor and the noise is louder than when the engine output is kept constant. In addition, in order to improve environmental problems, there is a strong demand for the immediate commercialization of low-emission vehicles such as electric vehicles. In particular, the development of a hybrid vehicle that can reduce energy consumption and exhaust gas emissions while maintaining almost the same performance as existing vehicles is being urgently promoted.

【0005】

In an electric vehicle, for example, Japanese Patent Application Laid-Open No. 57-142104 discloses an electric vehicle in which the output torque of a traveling motor is controlled to enable constant speed traveling in order to keep the set speed constant. However, a constant-speed running control system for a hybrid vehicle that takes advantage of having two drive propulsion devices, an engine and a running motor, is not known. In view of these conventional problems, the present invention has improved fuel efficiency, reduced noise, and improved tracking accuracy with respect to constant speed running speed by taking advantage of the hybrid vehicle when performing constant speed running. An object of the present invention is to provide a constant speed running control system for a vehicle.

【0006】

[Means for solving problems]

Therefore, in the present invention, in the constant speed running control system for a vehicle in which a vehicle equipped with an engine and a drive propulsion device other than the engine is driven at a constant speed at a set speed, a vehicle speed sensor for detecting the traveling vehicle speed and the vehicle are driven at a constant speed. It has a speed setting unit that sets a constant speed running speed and a constant speed running control unit that runs the vehicle at a constant speed at a constant speed, and the constant speed running control unit sets the output of the engine in the speed setting unit. The output is maintained at a constant output according to the speed, and the output of the drive propulsion device other than the engine is controlled so that the traveling vehicle speed detected by the vehicle speed sensor becomes equal to the speed set by the speed setting unit.

【0007】

The drive propulsion device other than the engine is preferably a motor. Further, it has a battery that can be charged by the output of the engine and supplies electric power to the motor, and the constant speed running control unit uses the battery when the running vehicle speed detected by the vehicle speed sensor is slower than the constant speed running speed. When the motor is driven by electric power and the traveling vehicle speed detected by the vehicle speed sensor is faster than the constant speed traveling speed, the extra output can be applied to charge the battery.

【0008】

Further, it has a battery remaining capacity detecting unit that detects the remaining capacity of the battery, and the constant speed running control unit performs constant speed running when the remaining battery capacity detected by the battery remaining capacity detecting unit is equal to or less than a predetermined amount. The output of the engine can also be set so that the battery charge exceeds the power consumption when doing so.

【0009】

[Action]

When traveling at a constant speed, the output of a drive propulsion device other than the engine, for example, a motor, is increased or decreased to control the traveling vehicle speed to be equal to the constant speed traveling speed, so that the output of the engine is kept constant. be able to. Compared to changing the engine output frequently, fuel efficiency is improved and noise is reduced. In addition, since the motor torque can be controlled more accurately than the output control of the engine, if the output torque is controlled by increasing or decreasing the motor torque for constant speed running, the accuracy of following the constant speed running speed can be improved. Can be improved.

【0010】

When the traveling vehicle speed is slower than the constant speed traveling speed, the electric power of the battery is used to drive the motor to increase the motor torque, and when the traveling vehicle speed is faster than the constant speed traveling speed, the surplus output is used as the battery. By applying the charge to the engine, the surplus output is not wasted while keeping the engine output constant when traveling at a constant speed. In addition, when the remaining capacity of the battery is less than the predetermined amount, the engine output is set so that the charged amount of the battery exceeds the power consumption, so that the insufficient remaining capacity of the battery is solved while running at a constant speed. be able to.

【0011】

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described with reference to examples. FIG. 1 is a block diagram showing a configuration of an embodiment. The output of the engine 1 is divided into two paths by the output dividing mechanism 2. One path is connected to the transaxle 3, and the driving force from the transaxle 3 is transmitted to both front wheels (not shown) via the left and right front wheel shafts. The other path is a path for generating electricity via the generator 4, and this electric power is used to drive the motor 6 and charge the battery 7 via the inverter 5. The engine 1 is connected to the constant speed running control unit 9 via the engine controller 8.

【0012】

The motor 6 is a traveling motor and is an AC induction motor. A transaxle 3 is connected to the motor 6, and the motor 6 is connected to the constant speed running control unit 9 via an inverter 5 and a motor controller 10. Further, the motor 6 is connected to the battery 7, which is the main power source for driving the vehicle, via the inverter 5. The motor controller 10 is also connected to the generator 4.

【0013】

The constant speed driving control unit 9 includes a battery remaining capacity detecting unit 11 that detects the remaining capacity of the battery, a vehicle speed sensor 12 that detects the traveling vehicle speed from the rotation of the wheels driven by the motor 1, and a traveling range from the position of the shift lever. The shift position detection unit 13 for detection, the constant speed running switch 14 for constant speed running provided near the driver's seat, and the brake switch 15 are connected. The brake switch 15 is attached to a brake pedal (not shown) and is a switch that is turned on by a minute stroke at the beginning of pressing the brake pedal.

【0014】

Next, the operation when traveling at a constant speed will be described. First, a constant speed running operation when the remaining capacity of the battery detected by the battery remaining capacity detection unit 11 exceeds a predetermined amount will be described. The driver operates the shift lever to set the drive range before actually driving at a constant speed. When the vehicle speed reaches the desired value, the constant speed traveling switch 14 is turned on. When the constant speed travel switch 14 is turned on, the constant speed travel control unit 9 first determines the shift position detected by the shift position detection unit 13 as the drive range, and the traveling vehicle speed detected by the vehicle speed sensor 12 is 40 km / h ~. It is determined whether or not the vehicle is within the range of 110 km / h and the brake switch 15 is in the off state, and if these conditions are satisfied, the vehicle shifts to the constant speed running state.

【0015】

When the state shifts to the constant speed running state, the running vehicle speed when the constant speed running switch 14 is turned on is set as the constant speed running speed. First, the engine output required for traveling at a constant speed is calculated, and the engine 1 is controlled by the engine controller 8. At the same time, the torque shared by the motor is calculated for the required driving force. The motor controller 10 drives the generator 4 to distribute the engine output to two systems so that the ratio of direct drive by the engine and drive via the motor is maximized.

【0016】

Every 96ms, the running vehicle speed newly input from the vehicle speed sensor 12 is compared with the set constant speed running speed, and the output torque required for running at the constant speed running speed is calculated. At this time, if the actual traveling vehicle speed is slower than the constant speed traveling speed, the motor controller 10 supplies electric power to the motor 6 to which electric power is supplied via the generator 4, and the battery 7 also supplies electric power to the motor. Increase the output torque of 6 to increase the driving force. When the actual traveling vehicle speed is faster than the constant traveling speed, the motor controller 10 reduces the electric power supplied from the engine 1 to the motor 6 via the generator 4, and reduces the output torque of the motor 6. That amount of power is charged from the inverter 5 to the battery 7.

【0017】

The operation when 60 km / h is set as the constant speed running speed will be described with reference to FIG. FIG. 2 (a) shows the relationship between the constant speed running speed and the actual running vehicle speed, and (b) shows the relationship between the engine output and the motor torque. The constant-speed running control unit 9 calculates the maximum efficiency torque M1 of the engine output E1 and the motor torque, which are the maximum efficiencies when traveling at 60 km / h. The engine output is held in E1, part of the engine output is used for direct drive, and the remaining output is converted to electric power by the generator 4. When the traveling vehicle speed is equal to the constant speed traveling speed, the electric power converted by the generator 4 is supplied to the motor 4, and the motor torque of the motor 4 becomes M1.

【0018】

As shown in (a) of FIG. 2, during the period from time a1 to time a2 in which the traveling vehicle speed is faster than the constant speed traveling speed, the electric power of the shaded portion shown in (b) of FIG. 2 is transferred from the inverter 5 to the motor 6. Not supplied and charged to the battery. The motor 6 outputs a motor torque smaller than the maximum efficiency torque M1. Since the traveling vehicle speed became slower than the constant speed traveling speed between the time a2 and the time a3, the output torque of the motor 6 was added by using the electric power of the battery 7, and the motor torque larger than the maximum efficiency torque was output.

【0019】

Similarly, the battery 7 is charged between the time a3 and the time a4. In this way, by repeatedly charging the battery 7 and supplying electric power from the battery 7 and increasing or decreasing the motor torque of the motor 6, constant speed running at approximately 60 km / h is performed. Also, once every 5 minutes, the total amount of battery charge and power consumption is calculated, and the output of engine 1 is modified so that the total amount becomes approximately 0, and then kept constant.

【0020】

Next, when the remaining capacity of the battery detected by the battery remaining capacity detection unit 11 is equal to or less than a predetermined amount, a constant speed running operation of performing constant speed running at 60 km / h as in (a) of FIG. 2 will be described. .. The set value of the engine output is different from the case where the remaining capacity of the battery exceeds the predetermined amount. As shown in FIG. 3, the constant speed running control unit 9 outputs an engine output E2 larger than the engine output E1 when traveling at 60 km / h when the remaining capacity of the battery is sufficient. Control engine 1 via 8.

【0021】

At the same time, the generator 4 is controlled via the motor controller 10 so that all the output other than the direct drive by the engine when traveling at 60 km / h when the remaining capacity of the battery is sufficient is converted into electric power. When all the electric power converted from the output other than the above direct drive component is supplied to the motor 6, the motor torque of the motor 6 becomes M2.

【0022】

Since the torque directly driven by the engine 1 has not changed, the motor torque required for constant speed running does not change from when the remaining capacity is sufficient, and the motor torque is the same as the value shown in Fig. 2 (b). Is required. However, since the electric power obtained through the generator 4 is larger than when the remaining capacity of the battery is sufficient, the value of the motor torque required to maintain the constant speed running speed is shown in the shaded area in FIG. When is M2 or less, there is surplus power. This extra power is used to charge the battery 7. Therefore, the battery 7 can be charged almost all the time.

【0023】

By the above operation, the engine output is kept constant regardless of the remaining capacity of the battery 7 when traveling at a constant speed, so that the fuel efficiency is improved as compared with the case where the engine output is changed frequently. There is less noise. If the remaining capacity of the battery exceeds a predetermined amount and the traveling vehicle speed is slower than the constant speed traveling speed, the power of the battery is used to increase the output torque of the motor, and the traveling vehicle speed becomes the constant speed. When the speed is faster than the running speed, the surplus output is used to charge the battery, so that the surplus output is not wasted while keeping the engine output constant. In addition, when the remaining capacity of the battery is less than the specified amount, the remaining capacity of the battery 7 is insufficient while running at a constant speed by setting the engine output so that the charge amount of the battery exceeds the power consumption amount. It can be resolved.

【0024】

[Effect of the invention]

As described above, in the constant-speed running control system for vehicles according to the present invention, constant-speed running is performed by increasing or decreasing the output torque of a drive propulsion device other than the engine, for example, a motor. It can be kept constant, fuel efficiency can be improved, noise can be reduced, and tracking accuracy with respect to a constant speed running speed can be improved. If the traveling vehicle speed is slower than the constant speed traveling speed, the power of the battery is used to increase the output torque of the motor, and if the traveling vehicle speed is faster than the constant speed traveling speed, the surplus output is charged to the battery. By hitting against, energy can be efficiently used without wasting excess output while keeping the engine output constant when traveling at a constant speed. Furthermore, when the remaining capacity of the battery is less than the predetermined amount, the insufficient remaining capacity of the battery can be solved while running at a constant speed by setting the engine output so that the charge amount of the battery exceeds the power consumption. Can be done.

[Simple explanation of drawings]

[Figure 1]

It is a block diagram which shows the structure of the Example of this invention.

[Figure 2]

It is a figure explaining the operation in an Example.

[Fig. 3]

It is a figure explaining the operation in an Example.

[Explanation of symbols]

1 engine 2 Output split mechanism 3 transaxle 4 generator 5 Inverter 6 motor 7 battery 8 engine controller 9 Constant speed running control unit 10 motor controller 11 Battery remaining capacity detector 12 Vehicle speed sensor 13 Shift position detector 14 Constant speed travel switch 15 Brake switch