JP5045234B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicular travel control apparatus that performs travel control using electric power generated by a vehicle.

Conventionally, as described in JP-A-2006-220045, a hybrid vehicle including a motor generator that functions as a generator when a vehicle is decelerated is known as a vehicle that generates electric power. In this hybrid vehicle, electric power generated by a motor generator during deceleration is stored in a battery, and electric power is supplied to the motor generator during driving so as to function as an electric motor.
JP 2006-220045 A

  In such a vehicle, since the electric power generated by the vehicle is stored in the battery, it is necessary to mount a heavy battery on the vehicle. In this case, the weight of the battery causes the fuel consumption of the vehicle to deteriorate. For this reason, development of a technique for effectively using the power generated by the vehicle without storing it in the battery is desired.

  Accordingly, an object of the present invention is to provide a vehicular travel control device that can effectively use electric power generated by a vehicle without accumulating power.

That is, the vehicular travel control device according to the present invention functions as an exhaust heat power generation unit that generates electric power by exhaust heat generated in the vehicle, an electromagnetic retarder that applies braking force to the vehicle by supplying electric power, and functions as an electric motor by supplying electric power. A motor generator that provides a driving force to the vehicle, functions as a generator by supplying the driving force, and generates electric power; and supplies the electric power generated by the exhaust heat power generation means to the motor generator during driving of the vehicle, Power supply control means for supplying the electric power generated by the motor generator to the electromagnetic retarder when the vehicle decelerates, and the exhaust heat power generation according to the rotational speed of the motor generator and the maximum power of the exhaust heat power generation means. structure and a transformer means for transforming the electric power generated by the means into a voltage corresponding to the drive request of the motor-generator It is.

  According to the present invention, the electric power generated by the exhaust heat power generation means during driving of the vehicle is supplied to the motor generator and used as the driving force for driving, and the electric power generated by the motor generator during deceleration of the vehicle is electromagnetic The electric power can be supplied to the retarder and used as a braking force. For this reason, the electric power generated when the vehicle is driven and decelerated can be effectively used without being stored in the battery.

  Moreover, it is preferable that the vehicle travel control apparatus according to the present invention is mounted on a transportation vehicle.

  According to the present invention, the electric power generated when the vehicle is decelerated is supplied to the electromagnetic retarder and used as an auxiliary brake force, and the electric power generated when the vehicle is driven is supplied to the motor generator and used as the driving force. The generated power can be used effectively without storing it.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram of a vehicle travel control apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, a vehicular travel control device 1 according to the present embodiment is a device that performs travel control using electric power generated by a vehicle as a travel driving force or a travel braking force, and is mounted on, for example, a transportation vehicle. The The transportation vehicle corresponds to, for example, a truck that travels on an expressway or an automobile road. The vehicle travel control device 1 includes an exhaust heat power generation unit 2, an electromagnetic retarder 3, a motor generator 4, and an ECU (Electronic Control Unit) 5.

  The exhaust heat power generation unit 2 is exhaust heat power generation means for generating power by exhaust heat from a heat source mounted on a vehicle, and is attached to, for example, an exhaust pipe 12 connected to the engine 11, and by exhaust heat of exhaust gas from the engine 11. What generates electricity is used. In this case, the exhaust heat power generation unit 2 may be any unit that can generate power by obtaining the heat energy of the exhaust heat. For example, a unit provided with a thermoelectric conversion element is used.

  The electromagnetic retarder 3 is operated by supplying electric power to give a braking force to the vehicle, and includes, for example, a rotor 31 and an excitation unit 32. The rotor 31 is a steel ring body, is attached to a drive shaft 13 such as a propeller shaft of a vehicle, and rotates together with the drive shaft 13. The excitation unit 32 generates a magnetic field when the vehicle is decelerated to generate an eddy current in the rotor 31, and is configured by a coil or the like. The excitation unit 32 is disposed at a predetermined distance from the circumferential surface of the rotor 31. In FIG. 1, the rotor 31 is disposed on the outer peripheral side, but may be disposed on the inner surface side of the rotor 31.

  The motor generator 4 functions as an electric motor by supplying electric power to give a driving driving force to the vehicle, and functions as a generator by supplying the driving driving force to generate electric power. The motor generator 4 is attached to a drive shaft 13 of the vehicle.

  The ECU 5 controls the entire apparatus, and includes, for example, a CPU, a ROM, a RAM, an input signal circuit, an output signal circuit, a power supply circuit, and the like. The ECU 5 supplies electric power generated by the exhaust heat power generation unit 2 during driving of the vehicle to the motor generator 4 and supplies electric power generated by the motor generator 4 to the electromagnetic retarder 3 during deceleration of the vehicle. Functions as a means.

  The vehicle travel control apparatus 1 includes a connection switching unit 6, a switching unit 7, and a DC transformer 8. The connection switching unit 6 switches the connection between the exhaust heat power generation unit 2, the electromagnetic retarder 3, and the motor generator 4, and performs connection switching in response to a switching control signal from the ECU 5. The connection switching unit 6 includes a switch that can be switched in response to a switching control signal from the ECU 5, and performs connection switching between the motor generator 4, the exhaust heat power generation unit 2 side, and the electromagnetic retarder 3 side.

  The switching unit 7 switches a voltage supplied when the electromagnetic retarder 3 is operated, and includes a switch that switches in response to an operation control signal from the ECU 5. The switching unit 7 is disposed between the connection switching unit 6 and the electromagnetic retarder 3.

  The DC transformer 8 is a transforming means for transforming the voltage generated by the exhaust heat power generation unit 2 into a voltage corresponding to a drive request of the motor generator 4 and operates in response to a transformation control signal from the ECU 5. The DC transformer 8 is disposed between the exhaust heat power generation unit 2 and the connection switching unit 6.

  A retarder lever 91, a throttle sensor 92, and a clutch pedal sensor 93 are connected to the ECU 5. The retarder lever 91 is an operation lever of the electromagnetic retarder 3 and inputs a retarder operation signal to the ECU 5. The throttle sensor 92 is a sensor that detects the throttle opening of the throttle valve, and inputs a throttle opening signal to the ECU 5. The clutch pedal sensor 93 is a sensor that detects the depression amount of the clutch pedal, and inputs an operation signal of the clutch pedal to the ECU 5.

  Next, the operation of the vehicle travel control device 1 according to the present embodiment will be described.

  FIG. 2 is a flowchart showing the basic operation of the vehicle travel control apparatus 1 according to the present embodiment. The control process in FIG. 2 is repeatedly executed at predetermined time intervals (for example, about 10 ms) by the ECU 5, for example. FIG. 3 is a flowchart showing an input voltage calculation process of the motor generator 4 in the vehicle travel control apparatus 1 according to the present embodiment.

  First, as shown in S10 of FIG. 2, a driving operation information reading process is performed. The driving operation information reading process is a process of reading information relating to driving operation, for example, an operation signal of the retarder lever 91, a slot opening signal, and a clutch pedal signal.

  Then, the process proceeds to S12 to determine whether or not there is a retarder operation request. This determination is made based on the operation signal of the retarder lever 91. For example, when the operation signal of the retarder lever 91 indicates ON, it is determined that there is a retarder operation request. When the operation signal of the retarder lever 91 indicates OFF, it is determined that there is no retarder operation request. Is done.

  If it is determined in S12 that there is no request for the retarder operation, the power generated by the exhaust heat power generation unit 2 is supplied to the motor generator 4 to cause the motor generator 4 to function as an electric motor. At that time, first, calculation processing of the power upper limit value P1 and the power conversion efficiency target value N1 is performed (S14). The power upper limit P1 is a value set based on the accelerator opening (throttle opening). For example, as shown in FIG. 4, a map of accelerator opening TA-power upper limit P1 preset in the ECU 5 is used. Is used to calculate. The power conversion efficiency target value N1 is a value that is set based on the clutch pedal position (pedal depression amount). For example, as shown in FIG. 5, the clutch pedal position X—the power conversion efficiency target value that is preset in the ECU 5 Calculation is performed using the map of N1. In FIG. 5, the greater the clutch pedal position X, the more the clutch is disengaged and the power conversion efficiency target value N1 is set smaller.

  Then, the process proceeds to S16, and the calculation process of the input voltage Vm input to the motor generator 4 is performed. The input voltage Vm input to the motor generator 4 is calculated using the power upper limit value P1 and the power conversion efficiency target value N1 calculated in S14. Details of the calculation process of the input voltage Vm will be described later.

  And it transfers to S18 and a transformation control process is performed. The transformation control process is a process for performing transformation control on the voltage output from the exhaust heat power generation unit 2, and outputs a transformation control signal from the ECU 5 to the DC transformer 8 so that the input voltage is Vm to the motor generator 4. As a result, as shown in FIG. 6, the electric power generated by the exhaust heat power generation unit 2 is transformed by the DC transformer 8 and input to the motor generator 4 via the connection switching unit 6. The motor generator 4 functions as an electric motor, and is rotationally driven to give a travel driving force T to the drive shaft 13.

  On the other hand, if it is determined in S12 that there is a retarder operation request, connection switching processing is performed. The connection switching process is a process of switching the switch connection of the connection switching unit 6 so that the motor generator 4 and the electromagnetic retarder 3 are connected. And it transfers to S22 and a retarder control process is performed. The retarder control process is a process for controlling the operation of the electromagnetic retarder 3 and is performed by outputting a control signal from the ECU 5 to the switching unit 7. As this control signal, a pulse signal for turning on and off the switch of the switching unit 7 is used. The braking force generated by the electromagnetic retarder 3 can be controlled by adjusting the duty ratio of the control signal.

  By performing this retarder control process, as shown in FIG. 7, the electric power generated by the motor generator 4 is input to the electromagnetic retarder 3 via the connection switching unit 6 and the switching unit 7. For this reason, the exciting part 32 of the electromagnetic retarder 3 generates a magnetic field and causes an eddy current in the rotor 31. Thereby, rotation of the rotor 31 is suppressed and a large braking force S1 is obtained. At this time, the braking force S2 is also generated in the motor generator 4 functioning as a generator, but is smaller than the braking force S1 generated by the electromagnetic retarder 3. When the processes of S18 and S22 are finished, the series of control processes is finished.

  Next, the input voltage calculation process in the vehicle travel control apparatus 1 according to the present embodiment will be described.

  This input voltage calculation process is a process of calculating the input voltage Vm input to the motor generator 4 when the electric power of the exhaust heat power generation unit 2 is supplied to the motor generator 4 to obtain the travel driving force. This process is a process executed in S16 of FIG. 2, and details thereof will be described with reference to FIG.

  First, as shown in S160 of FIG. 3, the output voltage Vs and output current Is of the exhaust heat power generation unit 2 are read. And the calculation process of the output electric power Ps of the exhaust heat power generation part 2 is performed (S161). The calculation process of the output power Ps is a process of calculating the output power Ps by multiplying the output voltage Vs and the output current Is.

  Then, the process proceeds to S162, in which the output power Ps of the exhaust heat power generation unit 2 is larger than the maximum output power value Psmax of the exhaust heat power generation unit 2, the power upper limit value P1 is larger than the maximum output power value Psmax of the exhaust heat power generation unit 2, It is determined whether or not the power conversion efficiency target value N1. In S162, the output power Ps of the exhaust heat power generation unit 2 is larger than the maximum output power value Psmax of the exhaust heat power generation unit 2, the power upper limit value P1 is larger than the maximum output power value Psmax of the exhaust heat power generation unit 2, and the power conversion efficiency target When it is determined that the value is N1, the output power Ps of the exhaust heat power generation unit 2 is set as the maximum output power value Psmax, and the value obtained by dividing the output voltage Vs by 2 as the exhaust heat power generation voltage value V0 (Vs / 2) is set.

  Then, the process proceeds to S164, and the calculation process of the voltage value Vm1 is performed. The voltage value Vm1 is a voltage value determined based on the power generation amount of the exhaust heat power generation unit 2, the rotation speed of the motor generator 4, and the like, and is calculated by the following equation (1).

Vm1 = (n · A + (n ² · A ² + 4 · Pm · Rm) ^1/2 ) / 2 (1)

  In this equation (1), n is the number of revolutions of the motor generator 4, A is a constant determined by the design of the motor generator 4, and Pm is a motor generator power consumption at which the smaller one of P1 and Psmax · N1 is set. (Min (P1, Psmax · N1)), Rm is an electric resistance value of the motor generator 4.

  Then, the process proceeds to S165, and the voltage fluctuation value ΔV is set. The voltage fluctuation value ΔV is a fluctuation value of the input voltage Vm. For example, a sine wave having an amplitude of about ¼ of the input voltage Vm is set. Then, the process proceeds to S166, and the calculation process of the input voltage Vm of the motor generator 4 is performed. This calculation process is a process for calculating the input voltage Vm by adding the voltage value Vm1 and the voltage fluctuation value ΔV as shown in the following equation (2).

  Vm = Vm1 + ΔV (2)

  When the process of S166 is finished, a series of control processes are finished.

  As described above, according to the vehicle travel control device 1 according to the present embodiment, the electric power generated by the exhaust heat power generation unit 2 during driving of the vehicle is supplied to the motor generator 4 and the electric power is used as the driving force. The electric power generated by the motor generator 4 when the vehicle is decelerated can be supplied to the electromagnetic retarder 3 and used as a braking force. For this reason, the electric power generated when the vehicle is driven and decelerated can be effectively used without being stored in the battery.

  In addition, according to the vehicle travel control device 1 according to the present embodiment, since the electric power generated by the vehicle is used as the driving force or braking force of the vehicle without being stored in the battery, the vehicle weight is not increased by mounting the battery. . Therefore, the generated power can be used effectively while preventing the deterioration of the fuel consumption of the vehicle. Therefore, it is very useful when applied to a transportation vehicle. It is particularly suitable for long-distance transportation vehicles traveling on highways and large cargo vehicles equipped with retarders.

  Further, when the electric power generated by the exhaust heat power generation unit 2 during driving of the vehicle is supplied to the motor generator 4, the input voltage is calculated according to the rotation speed of the motor generator 4, and the maximum power of the exhaust heat power generation unit 2 is calculated. Accordingly, the DC transformer 8 performs the transformation control, so that the electric power necessary for driving the motor generator 4 can be appropriately supplied. Further, by setting the transformation efficiency as variables (P1, N1) of the accelerator opening and the clutch pedal position, the power desired by the driver can be obtained.

  Each embodiment mentioned above shows an example of the vehicular travel control device concerning the present invention. The vehicular travel control device according to the present invention is not limited to such a configuration, and the vehicular travel control device according to the embodiment is modified so as not to change the gist described in each claim. It may be applied to a thing.

1 is a schematic configuration diagram of a vehicle travel control apparatus according to an embodiment of the present invention. It is a flowchart which shows the basic operation | movement process in the vehicle travel control apparatus of FIG. It is a flowchart which shows the input voltage calculation process in the traveling control apparatus for vehicles of FIG. It is explanatory drawing of the map used for the calculation of the electric power upper limit in the input voltage calculation process of FIG. It is explanatory drawing of the map used for the calculation of the power conversion efficiency target value in the input voltage calculation process of FIG. It is operation | movement explanatory drawing at the time of the travel drive of the vehicle travel control apparatus of FIG. It is operation | movement explanatory drawing at the time of deceleration of the vehicle travel control apparatus of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle travel control apparatus, 2 ... Waste heat power generation part, 3 ... Electromagnetic retarder, 4 ... Motor generator, 5 ... ECU, 6 ... Connection switching part, 7 ... Switching part, 8 ... DC transformer.

Claims (3)

Waste heat power generation means for generating power by exhaust heat generated in the vehicle;
An electromagnetic retarder for applying braking force to the vehicle by supplying power;
A motor generator that functions as an electric motor by supplying electric power to give the vehicle a driving force, and functions as a generator by supplying the driving force to generate electricity;
Power supply control means for supplying the electric power generated by the exhaust heat power generation means to the motor generator during driving of the vehicle and for supplying the electric power generated by the motor generator to the electromagnetic retarder during deceleration of the vehicle; ,
Transformer means for transforming the electric power generated by the exhaust heat power generation means into a voltage corresponding to a drive request of the motor generator according to the rotation speed of the motor generator and the maximum power of the exhaust heat power generation means,
A vehicle travel control apparatus comprising:   The vehicle travel control device according to claim 1, wherein the vehicle travel control device is mounted on a transport vehicle. The power supply control means calculates an input voltage input to the motor generator using a value set based on an accelerator opening and a value set based on a clutch pedal position. The vehicle travel control apparatus according to claim 1 or 2.

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