control system

Abstract

We provide technology for efficiently utilizing regenerative power. [Solution] A control system for a vehicle equipped with a secondary battery comprises: a regenerative power generation unit that converts kinetic energy into electrical energy to generate regenerative power; a heater that controls the temperature inside the vehicle's cabin; and a control unit that supplies the regenerative power generated by the regenerative power generation unit to the heater that controls the temperature inside the vehicle's cabin, based on parameters indicating the vehicle's driving state and the charge state of the secondary battery.

Description

[Technical Field]

[0001] The technology disclosed in the present specification relates to a control system for a vehicle including a secondary battery. [Background Art]

[0002] Technologies for utilizing regenerative electric power have been developed for vehicles including a secondary battery. For example, Patent Literature 1 discloses a technology for supplying regenerative electric power to a secondary battery to charge the secondary battery while the vehicle is traveling. In Patent Literature 1, when the secondary battery is sufficiently charged and can no longer be charged, the regenerative electric power is supplied to a heater. [Prior Art Literature] [Patent Literature]

[0003] [Patent Literature 1] Japanese Unexamined Patent Publication No. 2021-16250 [Summary of Invention] [Problem to be Solved by Invention]

[0004] In Patent Literature 1, regenerative electric power is supplied to the heater when it is determined that the secondary battery cannot be charged. However, depending on the traveling state of the vehicle, a large amount of regenerative electric power may be generated in some cases, and a small amount may be generated in other cases. If only excess electric power that cannot be charged into the secondary battery is supplied to the heater, the generated regenerative electric power cannot be effectively used according to the power consumption of the vehicle.

[0005] The present specification discloses a technology for efficiently utilizing regenerative electric power. [Means for Solving the Problem]

[0006] In a first aspect of this technology, a vehicle control system equipped with a secondary battery includes: a regenerative power generation unit that converts kinetic energy into electrical energy to generate regenerative power; a heater that controls the temperature inside the vehicle's cabin; and a control unit that supplies the regenerative power generated by the regenerative power generation unit to the heater that controls the temperature inside the vehicle's cabin, based on parameters indicating the vehicle's driving state and the charge state of the secondary battery.

[0007] This configuration supplies regenerative power to the heater based not only on the charge state of the secondary battery but also on parameters indicating the vehicle's driving state. Therefore, regenerative power can be effectively utilized according to the vehicle's power consumption. Furthermore, by supplying regenerative power to the heater, reverse current flow to the secondary battery and overcurrent to the motor, etc., can be suppressed.

[0008] In a second aspect of this technology, in the first aspect described above, the parameter may be the inclination angle of the vehicle. The control unit may determine the driving state of the vehicle based on the inclination angle and, when it determines that the vehicle is driving downhill, may supply the regenerative power to the heater.

[0009] This configuration allows for a more accurate determination of the vehicle's driving state by using the vehicle's inclination angle as a parameter. Furthermore, when the vehicle is traveling downhill, a significant amount of regenerative power can be generated. By supplying this regenerative power to the heater when the vehicle is traveling downhill, the heater can be supplied with regenerative power when a large amount is being generated.

[0010] In a third aspect of this technology, in the first or second aspect described above, the parameter may be the power consumption of the vehicle. The control unit may identify the driving state of the vehicle based on the power consumption and supply the regenerative power to the heater.

[0011] With this configuration, by using power consumption as a parameter, the vehicle's driving state (for example, whether it is moving or stopped, or whether the brakes are applied or not) can be determined more accurately. As a result, the control unit can more easily decide whether or not to supply regenerative power to the heater.

[0012] In a fourth aspect of this technology, in any one of the first to third aspects described above, the charge state of the secondary battery may be determined by the charge amount of the secondary battery. The control unit may supply the regenerative power to the heater if the charge amount of the secondary battery is greater than or equal to a predetermined value.

[0013] In this configuration, when the charge level of the secondary battery exceeds a predetermined value, regenerative power is supplied to the heater. This prevents the secondary battery from becoming overcharged and suppresses its degradation.

[0014] In a fifth aspect of this technology, in any one of the first to fourth aspects described above, the vehicle may be equipped with a temperature sensor for measuring the temperature of the heater. The control unit may stop supplying the regenerative power to the heater if the temperature measured by the temperature sensor exceeds a predetermined temperature while the regenerative power is being supplied to the heater.

[0015] With this configuration, the supply of regenerative power to the heater is stopped when the heater temperature exceeds a predetermined value, thereby suppressing heater overheating. [Brief explanation of the drawing]

[0016] [Figure 1] A block diagram showing the schematic configuration of the vehicle according to the embodiment. [Figure 2] A flowchart illustrating an example of a process for controlling the destination of regenerative power. [Modes for carrying out the invention]

[0017] The control system 10 of this embodiment will now be described. The control system 10 shown in Figure 1 controls regenerative power in a vehicle equipped with a secondary battery 12. The vehicle on which the control system 10 is installed is an electric vehicle equipped with a secondary battery 12 and a driving motor (not shown). For example, the vehicle may be an electric vehicle (EV) or a hybrid vehicle (HV). As shown in Figure 1, the vehicle is equipped with a secondary battery 12, a heater 14, a regenerative power generation unit 20, a regenerative power control unit 22, a heater temperature sensor 30, a secondary battery temperature sensor 32, a tilt sensor 34, and a passenger compartment temperature sensor 36. The secondary battery 12 stores power to be supplied to the vehicle's driving motor (not shown). The vehicle's driving motor also functions as a generator that generates regenerative power. The heater 14 is a high-voltage heater (HVH) and adjusts the temperature of the vehicle's passenger compartment.

[0018] The regenerative power generation unit 20 is equipped with a generator (the vehicle's driving motor). The regenerative power generation unit 20 generates regenerative power by converting the kinetic energy generated by the vehicle's movement into electrical energy using the generator. For example, the regenerative power generation unit 20 generates regenerative power when the vehicle's accelerator pedal is not pressed. The regenerative power generation unit 20 can generate a relatively large amount of regenerative power when the vehicle is traveling downhill.

[0019] The regenerative power control unit 22 controls the regenerative power generation unit 20. Specifically, the regenerative power control unit 22 determines whether the regenerative power generated by the regenerative power generation unit 20 is to be supplied to the secondary battery 12 or the heater 14, and instructs the regenerative power generation unit 20 of the determination. The regenerative power control unit 22 acquires information on various measurement values described later from the heater temperature sensor 30, the secondary battery temperature sensor 32, the inclination sensor 34, and the vehicle compartment temperature sensor 36. Furthermore, the regenerative power control unit 22 acquires information on the amount of power stored in the secondary battery 12 (hereinafter also referred to as the charged amount) from the secondary battery 12. Note that the regenerative power control unit 22 may also acquire information on the charged amount of the secondary battery 12 from a control device 40 that controls a traveling motor (not shown) of the vehicle or the like. The regenerative power control unit 22 uses the acquired various types of information to determine whether the regenerative power generated by the regenerative power generation unit 20 is to be supplied to the secondary battery 12 or the heater 14.

[0020] The heater temperature sensor 30 measures the temperature of the heater 14. The heater temperature sensor 30 outputs information of the measured temperature of the heater 14 to the regenerative power control unit 22.

[0021] The secondary battery temperature sensor 32 measures the temperature of the secondary battery 12. The secondary battery temperature sensor 32 outputs information of the measured temperature of the secondary battery 12 to the regenerative power control unit 22.

[0022] The inclination sensor 34 measures the inclination angle of the vehicle relative to the horizontal. In the present embodiment, the inclination sensor 34 is an acceleration sensor. By using an acceleration sensor as the inclination sensor 34, the inclination angle of the vehicle can be measured, and it can be detected whether the vehicle is traveling on an uphill or a downhill. Note that the inclination sensor 34 may be another type of inclination sensor, and may be a gyro sensor, for example. The inclination sensor 34 outputs information of the measured inclination angle of the vehicle to the regenerative power control unit 22.

[0023] The vehicle compartment temperature sensor 36 measures the temperature inside the vehicle compartment (not shown) of the vehicle. The vehicle compartment temperature sensor 36 outputs information of the measured vehicle compartment temperature of the vehicle to the regenerative power control unit 22.

[0024] Next, a process for controlling the supply destination of the regenerative electric power generated by the regenerative electric power generation unit 20 will be described with reference to FIG. 2. The process illustrated in FIG. 2 is started, for example, when a main switch of a vehicle is turned on. As shown in FIG. 2, in S12, the regenerative power control unit 22 determines whether or not the vehicle is traveling. Specifically, the regenerative power control unit 22 acquires information on the charge amount of the secondary battery 12 from the secondary battery 12. Then, the regenerative power control unit 22 calculates power consumption based on the acquired information on the charge amount of the secondary battery 12. Note that the regenerative power control unit 22 may acquire information on power consumption from the control device 40. The regenerative power control unit 22 determines whether the vehicle is traveling or stopped based on the power consumption information. No regenerative power is generated while the vehicle is stopped. Therefore, if the vehicle is stopped (NO in S12), the process returns to S12 and waits until the vehicle starts traveling.

[0025] If the vehicle is traveling (YES in S12), in S14, the regenerative power control unit 22 determines whether or not the vehicle is traveling downhill. Specifically, the regenerative power control unit 22 acquires information on the inclination angle of the vehicle from the inclination sensor 34. The regenerative power control unit 22 determines whether or not the vehicle is traveling downhill based on the acquired inclination angle information.

[0026] When the vehicle is traveling downhill (YES in S14), a large amount of regenerative power is likely to be generated. Therefore, in S16, the regenerative power control unit 22 determines whether or not the charge amount of the secondary battery 12 is equal to or greater than a predetermined value. The predetermined value is a value with which it can be determined that the secondary battery 12 is sufficiently charged, and is, for example, 90% of the full charge amount. Note that the predetermined value may be a value (for example, 70% of the full charge amount) with which it can be determined that a certain amount of power is charged in the secondary battery 12 (for example, the charge amount of the secondary battery 12 is not insufficient).

[0027] If the charge level of the secondary battery 12 is less than a predetermined value (NO in S16), the regenerative power control unit 22 determines that the charge level of the secondary battery 12 is insufficient. Then, in S18, the regenerative power control unit 22 instructs the regenerative power generation unit 20 to supply the generated regenerative power to the secondary battery 12. As a result, the regenerative power generation unit 20 supplies the generated regenerative power to the secondary battery 12. After that, the process returns to S12 and repeats the process from S12 onward.

[0028] If the charge level of the secondary battery 12 is above a predetermined value (YES in S16), the regenerative power control unit 22 determines that the charge level of the secondary battery 12 is sufficient. In this case, the regenerative power control unit 22 does not supply the regenerative power generated by the regenerative power generation unit 20 to the secondary battery 12. This prevents the secondary battery 12 from becoming overcharged and suppresses the deterioration of the secondary battery 12. Then, in S20, the regenerative power control unit 22 determines whether the heater 14 is hot or not. Specifically, the regenerative power control unit 22 obtains information on the temperature of the heater 14 from the heater temperature sensor 30. Based on the acquired information on the temperature of the heater 14, the regenerative power control unit 22 determines whether the heater 14 is hotter than a predetermined temperature. The predetermined temperature is a temperature at which it can be determined that the heater 14 is overheating, for example, 100°C.

[0029] If the heater 14 is not hot (NO in S20), the regenerative power control unit 22 instructs the regenerative power generation unit 20 to supply the generated regenerative power to the heater 14. As a result, the regenerative power generation unit 20 supplies the generated regenerative power to the heater 14. After that, the process returns to S12 and repeats the process from S12 onward.

[0030] On the other hand, if the heater 14 is hot (YES in S20), the regenerative power control unit 22 instructs the regenerative power generation unit 20 to stop supplying the generated regenerative power to the heater 14. Specifically, if the regenerative power generation unit 20 is supplying regenerative power to the heater 14, the regenerative power generation unit 20 stops supplying regenerative power to the heater 14. Also, if the regenerative power generation unit 20 is not supplying regenerative power to the heater 14, the regenerative power generation unit 20 does not supply regenerative power to the heater 14. In this embodiment, if the heater 14 is hot, the supply of regenerative power to the heater 14 is stopped. Therefore, abnormal heating of the heater 14 can be suppressed. After that, the process returns to S12 and the process from S12 onwards is repeated.

[0031] Returning to S14, we will explain the case where the vehicle is not traveling downhill (NO in S14). That is, we will explain the case where the regenerative power control unit 22 determines, based on the acquired inclination angle, that the vehicle is traveling uphill or on a flat surface. If NO in S14, in S26 the regenerative power control unit 22 determines whether the vehicle has applied the brakes. If the vehicle is not traveling downhill and the brakes have been applied (YES in S26), proceed to S16 and execute the processes from S16 to S24. Then, return to S12 and repeat the processes from S12 onward.

[0032] On the other hand, if the vehicle is not traveling downhill and the brakes are not applied (NO in S26), in S28, the regenerative power control unit 22 determines whether the passenger compartment is cold or not. If the passenger compartment is cold or not (YES in S28), the process proceeds to S20 and executes the processes in S20 to S24. In S20 to S24, regenerative power may be supplied to the heater 14, but not to the secondary battery 12. If the vehicle is traveling on a flat surface, or traveling uphill (NO in S14), and the brakes are not applied (NO in S26), the regenerative power is supplied to the heater 14 instead of the secondary battery 12, depending on whether the passenger compartment is cold or not.

[0033] On the other hand, if the passenger compartment is not cold (NO in S28), the process proceeds to S16, and the processes from S16 to S24 are executed. If the passenger compartment is not cold, there is no need to actively supply regenerative power to the heater 14. For this reason, in S16 to S24, regenerative power is supplied to the secondary battery 12 or the heater 14.

[0034] In this embodiment, in S16, the regenerative power control unit 22 determined whether to supply regenerative power to the secondary battery 12 or the heater 14 based on whether the charge level of the secondary battery 12 is above a predetermined value, but the configuration is not limited to this. For example, the regenerative power control unit 22 may determine whether to supply regenerative power to the secondary battery 12 or the heater 14 not only based on the charge level of the secondary battery 12, but also based on the temperature of the secondary battery 12. In this case, the vehicle is further equipped with a temperature sensor that measures the temperature of the secondary battery 12, and if the measurement value from this temperature sensor is outside a predetermined range (for example, below 0°C or above 100°C), the regenerative power control unit 22 may determine that the temperature of the secondary battery 12 is abnormal and supply regenerative power to the heater 14. Also, if the regenerative power control unit 22 receives information from the control device 40 that an abnormality has occurred in the secondary battery 12, it may supply regenerative power to the heater 14.

[0035] The following points should be noted regarding the control system 10 described in the embodiment. The regenerative power control unit 22 in the embodiment is an example of a "control unit," and the heater temperature sensor 30 is an example of a "temperature sensor."

[0036] The specific examples of the technology disclosed herein have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples described above. Furthermore, the technical elements described herein or in the drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated herein or in the drawings achieves multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of Symbols]

[0037] 10: Control System 12: Secondary battery 14: Heater 20: Regenerative power generation section 22: Regenerative Power Control Unit 30: Heater temperature sensor 32: Temperature sensor for secondary batteries 34: Tilt sensor 36: Vehicle interior temperature sensor

Claims

1. A control system for a vehicle equipped with a secondary battery, A regenerative power generation unit that converts kinetic energy into electrical energy to generate regenerative power, A heater that controls the temperature inside the vehicle, A control unit supplies the regenerative power generated by the regenerative power generation unit to the heater that controls the vehicle's interior temperature based on parameters indicating the vehicle's driving state and the charge state of the secondary battery. A control system equipped with the following features.

2. A control system according to claim 1, The aforementioned parameter is the inclination angle of the vehicle, The control unit is a control system that determines the driving state of the vehicle based on the inclination angle and, when it determines that the vehicle is driving downhill, supplies the regenerative power to the heater.

3. A control system according to claim 1, The aforementioned parameter is the power consumption of the vehicle, The control unit is a control system that identifies the driving state of the vehicle based on the power consumption and supplies the regenerative power to the heater.

4. A control system according to claim 1, The charge state of the secondary battery is determined by the amount of charge of the secondary battery. The control unit is a control system that supplies the regenerative power to the heater when the charge level of the secondary battery is above a predetermined value.

5. A control system according to claim 1, The vehicle is equipped with a temperature sensor for measuring the temperature of the heater. The control unit is a control system that stops supplying the regenerative power to the heater if the temperature measured by the temperature sensor exceeds a predetermined temperature while the regenerative power is being supplied to the heater.

Images