JP2017081353A - Electric car control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric car control device which can enhance energy recovery efficiency by a simple method without the need of acquisition and treatment of information by a GPS or communication means.SOLUTION: In an energy recovery mode selection unit, any one of a vehicle speed priority mode S8 for preferentially performing vehicle speed increase control on a descent ramp and a regenerative priority mode S6 for preferentially performing motor regenerative control is selected S4, 5 on the basis of a standard deviation σ based on slope history and a conversion efficiency η based on electric power history inputted to and outputted from a motor and a battery, and an auto-cruise control unit controls an engine, a motor and a brake according to the selected energy recovery mode S7.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for an electric vehicle, and more particularly, to energy recovery control when traveling on a downhill road by auto-cruise control.

  In order to improve the efficiency of an engine vehicle equipped with an engine as a conventional driving power source, a hybrid electric vehicle equipped with a motor (electric motor) as a driving power source in addition to the engine, or a motor instead of the engine Electric vehicles and the like (hereinafter sometimes collectively referred to as electric vehicles) have been put into practical use.

  In such an electric vehicle, since the motor can be operated as a generator by controlling the regeneration of the motor, for example, when traveling on a downhill road, the motor generates power by reverse driving from the drive wheel side, and the generated power is transferred to the battery. Charging. Thereby, the potential energy of the vehicle obtained on the downhill road can be recovered as electric energy, and the discharged electric power from the battery is used during the subsequent running by the motor.

  In addition, the potential energy of the vehicle on the downhill road can be recovered not only as electric energy but also as kinetic energy in the form of increasing vehicle speed. That is, it is possible to collect kinetic energy by increasing the vehicle speed without generating a driving force during traveling on a downhill road. Then, by coasting after the downhill road is completed, the vehicle speed is gradually reduced to consume kinetic energy, thereby reducing the load on the motor and engine and reducing fuel consumption (hereinafter referred to as such control). Is called vehicle speed increase control).

  On the other hand, in recent years, vehicles having an auto-cruise function for traveling while maintaining a target speed arbitrarily set by the driver have been widely used for the purpose of reducing the burden on the driver.

  For example, in Patent Document 1, in auto-cruise control in an electric vehicle, a downhill road ahead of the host vehicle is predicted, and the vehicle speed is gradually increased over the entire traveling period of the downhill road so that a part of the potential energy is kinetic energy. In addition, the residual potential energy is used for recovering electric energy by regenerative control of the motor. In Patent Document 1, the vehicle speed increase control and the motor regeneration control are simultaneously performed in parallel as described above, so that the energy consumption is higher than the sequential control such as the vehicle speed increase control after the motor regeneration control is performed. It has been found that the recovery efficiency is improved.

JP 2014-236626 A

  However, in Patent Document 1, it is assumed that the gradient and the total length of the downhill road ahead of the host vehicle can be predicted. That is, in Patent Document 1, by acquiring and processing GPS information, road traffic information, road-to-vehicle communication information, inter-vehicle communication information, and the like, the length of a downhill road ahead of the host vehicle is predicted and matched to the length. Thus, the vehicle speed can be increased at a substantially constant rate of change and the upper speed limit can be reached at the end of the downhill road.

  For this reason, if the vehicle does not have GPS or communication means, or if the GPS or communication means cannot obtain information normally due to equipment failure or geographical problems, the situation in front of the vehicle is accurately determined. It cannot be predicted and the technique of Patent Document 1 cannot be applied.

  The present invention has been made to solve such problems, and the object of the present invention is to improve the energy recovery efficiency by a simple method without the need to acquire and process information by GPS or communication means. It is an object of the present invention to provide an electric vehicle control apparatus that can be made to operate.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

  The control apparatus for an electric vehicle according to this application example includes a drive unit including an electric motor that is a drive source of a vehicle and can generate electricity and charge a battery, a brake unit that brakes the vehicle, the drive unit, and the brake Auto cruise control means for controlling the means to execute auto cruise control for driving the vehicle while maintaining the vehicle speed within a set vehicle speed range; and slope detecting means for detecting a road gradient on which the host vehicle is running; A power detection means for detecting power input and output by the motor and the battery; a storage means for storing the road gradient detected by the slope detection means; and the power detected by the power detection means; , Based on a road gradient history stored in the storage means, an index calculation means for calculating a potential energy index indicating the magnitude of potential energy in a predetermined section; Based on the power history stored in the storage means, the conversion efficiency calculation means for calculating the power conversion efficiency in the predetermined section, and the potential energy index calculated by the index calculation means as the energy recovery mode on the downhill road is predetermined. If it is greater than or equal to a value, or if the potential energy index is less than a predetermined value and the conversion efficiency calculated by the conversion efficiency calculation means is greater than or equal to a predetermined efficiency, the vehicle speed is increased to the upper limit of the vehicle speed range. After selecting a vehicle speed priority mode for performing regeneration control of the electric motor, and when the positional energy index is less than a predetermined value and the conversion efficiency is less than a predetermined efficiency, the charge amount of the battery is set to a predetermined charge amount. Energy recovery mode selection for selecting a regeneration priority mode for increasing the vehicle speed in the vehicle speed range after performing regeneration control of the electric motor until Includes a stage, the said auto-cruising control means controls the driving means and the braking means according to descending energy recovery mode selected from the energy recovery mode selecting means in the slope.

  According to the present invention using the above means, energy recovery efficiency can be improved by a simple method without requiring acquisition and processing of information by GPS or communication means.

1 is a schematic configuration diagram of a hybrid vehicle in an embodiment of the present invention. It is explanatory drawing which shows the procedure which calculates | requires standard deviation (sigma) from gradient log | history. FIG. 6 is a relationship diagram illustrating a relationship between a standard deviation σ based on a gradient history and energy related to vehicle travel. It is explanatory drawing which showed the energy recovery amount according to conversion efficiency (eta) in the case where (a) is small, (b) in the case of standard deviation (sigma), and (c) large. It is a flowchart which shows the energy recovery control routine in the downhill road which vehicle ECU performs.

  Hereinafter, an embodiment in which the present invention is embodied in a control apparatus for a hybrid truck will be described.

  FIG. 1 is an overall configuration diagram showing a hybrid truck on which the control device of this embodiment is mounted.

  The hybrid truck 1 is an electric vehicle of a so-called parallel hybrid vehicle, and may be referred to as a vehicle or a host vehicle in the following description. A vehicle 1 is equipped with a diesel engine (hereinafter referred to as an engine) 2 as a driving power source (driving means), and a motor 3 (electric motor) that can also operate as a generator such as a permanent magnet synchronous motor. . A clutch 4 is connected to the output shaft of the engine 2, and an input side of the automatic transmission 5 is connected to the clutch 4 via a rotating shaft of the motor 3. A differential device 7 is connected to the output side of the automatic transmission 5 via a propeller shaft 6, and left and right drive wheels 9 are connected to the differential device 7 via a drive shaft 8.

  The automatic transmission 5 automates the connection / disconnection operation of the clutch 4 and the switching operation of the shift stage based on a general manual transmission. In this embodiment, the automatic transmission 5 has a shift stage of 12 forward speeds and 1 reverse speed. ing. Of course, the configuration of the automatic transmission 5 is not limited to this, and can be arbitrarily changed. For example, the automatic transmission 5 may be embodied as a manual transmission, or a so-called dual clutch type automatic transmission having two power transmission systems. It may be embodied as a transmission.

  A battery 11 is connected to the motor 3 via an inverter / converter (hereinafter simply referred to as an inverter) 10. The DC power stored in the battery 11 is converted into AC power by the inverter 10 and supplied to the motor 3 (power running control), and the driving force generated by the motor 3 is transmitted to the drive wheels 9 after being shifted by the automatic transmission 5. The vehicle 1 is made to travel. For example, when the vehicle 1 decelerates or travels on a downhill road (regenerative travel), the motor 3 operates as a generator by reverse drive from the drive wheel 9 side (regenerative control). The negative driving force generated by the motor 3 is transmitted to the driving wheel 9 side as a braking force, and the AC power generated by the motor 3 is converted into DC power by the inverter 10 and charged to the battery 11.

  The driving force generated by the motor 3 is transmitted to the driving wheel 9 regardless of the state of connection / disconnection of the clutch 4, and the driving force generated by the engine 2 is driven only when the clutch 4 is connected. 9 side. Therefore, when the clutch 4 is disengaged, the positive or negative driving force generated by the motor 3 as described above is transmitted to the driving wheel 9 side, and the vehicle 1 travels. When the clutch 4 is connected, the driving force of the engine 2 and the motor 3 is transmitted to the driving wheel 9 side, or only the driving force of the engine 2 is transmitted to the driving wheel side, so that the vehicle 1 travels.

  The vehicle ECU 13 is a control circuit for integrated control of the entire vehicle. For this purpose, the vehicle ECU 13 includes an accelerator sensor 15 that detects the amount of operation of the accelerator pedal 14, a brake switch 17 that detects the depression of the brake pedal 16, a vehicle speed sensor 18 that detects the speed V of the vehicle 1, and the rotational speed of the engine 2. Various sensors and switches such as an engine rotation speed sensor 19 for detecting the rotation speed and a motor rotation speed sensor 20 for detecting the rotation speed of the motor 3 are connected.

  The vehicle ECU 13 is connected with an actuator (not shown) for connecting / disconnecting the clutch 4 and an actuator for shifting the automatic transmission 5, and an engine ECU 22 for engine control and an inverter ECU 23 for inverter control. And a battery ECU 24 for managing the battery 11 are connected.

  The vehicle ECU 13 calculates a required torque required for the vehicle 1 to travel based on the accelerator operation amount by the driver, and the vehicle 1 based on the required torque, SOC (State Of Charge) (charge amount) of the battery 11, and the like. Select the driving mode. In this embodiment, an E / G mode that uses only the driving force of the engine 2, an EV mode that uses only the driving force of the motor 3, and an HEV mode that uses both the driving force of the engine 2 and the motor 3 are set as the traveling mode. The vehicle ECU 13 selects one of the travel modes.

  The vehicle ECU 13 converts the required torque into a torque command value to be output by the engine 2 or the motor 3 based on the selected travel mode. For example, in the HEV mode, the required torque is distributed to the engine 2 side and the motor 3 side, and torque command values for the engine 2 and the motor 3 are calculated based on the gear position at that time. In the E / G mode, the required torque is converted into a torque command value for the engine 2 based on the gear position, and in the EV mode, the required torque is converted into a torque command value for the motor 3 based on the gear speed.

  Then, the vehicle ECU 13 disconnects the clutch 4 in the EV mode and connects the clutch 4 in the E / G mode and HEV mode in order to execute the selected travel mode, and then sends a torque command value to the engine ECU 22 and the inverter ECU 23. Output as appropriate. Further, while the vehicle 1 is traveling, the vehicle ECU 13 calculates a target gear position from a shift map (not shown) based on the accelerator operation amount, the vehicle speed V, and the like, and the actuator 4 connects and disconnects the clutch 4 to achieve this target gear position. And a gear change operation.

  On the other hand, the engine ECU 22 executes injection amount control and injection timing control so as to achieve the travel mode and torque command value input from the vehicle ECU 13. For example, in the E / G mode and the HEV mode, the driving force is generated in the engine 2 with respect to the positive torque command value, and the engine brake is generated with respect to the negative torque command value. Further, in the EV mode, the engine 2 is stopped and held by stopping the fuel injection or is set in an idle operation state.

  Further, the inverter ECU 23 drives and controls the inverter 10 so as to achieve the travel mode and the torque command value input from the vehicle ECU 13. For example, in the EV mode or HEV mode, the motor 3 is controlled by powering the positive torque command value to generate a positive driving force, and the motor 3 is regeneratively controlled to the negative torque command value. Generate negative driving force. In the E / G mode, the driving force of the motor 3 is controlled to zero.

  Further, the inverter ECU 23 receives power input / output from the motor 3, that is, power consumption by the motor 3 and power generated by the motor 3, power input / output from the battery 11, that is, power supplied from the battery 11 to the motor 3 and The charging power received by the power generation of the motor 3 is detected (power detection means).

  The battery ECU 24 detects the temperature of the battery 11, the voltage of the battery 11, the current flowing between the inverter 10 and the battery 11, etc., calculates the SOC of the battery 11 from these detection results, and uses this SOC together with the detection results. Output to the vehicle ECU 13.

  A navigation device 31 and a communication device 32 are connected to the vehicle ECU 13. The navigation device 31 determines the position of the vehicle on the map while the vehicle 1 is traveling based on the map data stored in its own storage area and the GPS information or VICS (registered trademark) information received via the antenna. Identify. The communication device 32 performs road-to-vehicle communication with a roadside communication system of a data center that is appropriately installed on the roadside, and performs vehicle-to-vehicle communication with other vehicles that are traveling around.

  Information to be communicated varies widely, for example, map information that the vehicle does not have, road information (road curves and gradients, etc.), traffic information (congestion information, accident information, construction information, etc.), or local information (tourist spots) Or the like) from the roadside communication system or other vehicles, or conversely, such information is supplied to other vehicles.

  The vehicle ECU 13 is also connected to various sensors such as a gradient sensor 33 (gradient detection means) that detects a road gradient on which the host vehicle is traveling.

  Furthermore, a braking device 34 (braking means) provided in the vehicle 1 is connected to the vehicle ECU 13. Specifically, the braking device 34 is one or more of a retarder, a compression release brake of the engine 2, an exhaust brake, and the like. The vehicle ECU 13 arbitrarily controls the braking device 34 to apply a braking force to the traveling vehicle 1.

  The vehicle ECU 13 includes an auto cruise control unit 40 (auto cruise control means) that executes auto cruise control. When the driver operates an auto cruise control execution switch (not shown) to set the target vehicle speed Vtgt, the auto cruise control unit 40 sets a vehicle speed range including an upper limit speed VHi and a lower limit speed VLo with respect to the target vehicle speed Vtgt. While the vehicle 1 is traveling, the driving force of the engine 2 and the motor 3 and the braking force of the braking device 34 are appropriately controlled to keep the vehicle speed V within the set vehicle speed range.

  The auto-cruise control unit 40 sets the required torque on the negative side to maintain the vehicle speed V while traveling on a downhill road by auto-cruise control, and moves the potential energy of the vehicle 1 while achieving the required torque. Vehicle speed increase control and regenerative control of the motor 3 are executed in order to collect energy and electric energy.

  When the auto cruise control unit 40 can normally acquire various types of information from the navigation device 31 and the communication device 32, the downhill road existing ahead of the own vehicle 1 before the own vehicle 1 actually travels on the downhill road. Get information about. Then, the vehicle speed V when the vehicle 1 reaches the downhill road (starting point of the downhill road) and the length L of the downhill road are predicted, and the vehicle speed V is set to a substantially constant vehicle speed with the length L of the downhill road. Vehicle speed increase control is executed so as to increase to the upper limit speed VHi at an increase rate, and regenerative control of the motor 3 is executed in parallel with this.

  On the other hand, the auto-cruise control unit 40 is based on the driving history when various information cannot be normally acquired from the navigation device 31 and the communication device 32 due to equipment failure or geographical problem, and thus predictive control is impossible. The energy recovery mode on the downhill road is selected according to the index of potential energy and the power conversion efficiency between the motor 3 and the battery 11.

  Here, as the energy recovery mode in the present embodiment, the vehicle speed priority mode in which regeneration control of the motor 3 is performed after the vehicle speed V is increased to the upper limit speed VHi of the vehicle speed range set on the downhill road, and the battery 11 on the downhill road. There is a regeneration priority mode in which the vehicle speed is increased in the vehicle speed range set after the regeneration control of the motor 3 is performed until the SOC reaches a predetermined SOC.

  The vehicle ECU 13 uses the road gradient information detected by the gradient sensor 33 and the motor 3 and the battery 11 detected by the inverter ECU 23 to select the energy recovery mode on the downhill road in a state where the predictive control is impossible. A storage unit 41 (storage unit) capable of storing input / output power, a standard deviation calculation unit 42 (index calculation unit) that calculates a standard deviation σ of a predetermined section based on a road gradient history stored in the storage unit 41, and storage A conversion efficiency calculation unit 43 (conversion efficiency calculation means) that calculates the average conversion efficiency η of power in a predetermined section based on the power history stored in the unit 41, energy recovery on the downhill road based on the standard deviation σ and the average conversion efficiency η It has an energy recovery mode selection unit 44 (energy recovery mode selection means) for selecting a mode.

  Specifically, road gradient information that changes momentarily as the vehicle 1 travels and electric power that is input and output by the motor 3 and the battery 11 are sent from the gradient sensor 33 and the inverter ECU 23 to the storage unit 41. Gradient history and power history for the past predetermined travel distance (predetermined section) are accumulated.

  The standard deviation calculation unit 42 creates a histogram as shown in FIG. 2 based on the gradient history for a predetermined travel distance stored in the storage unit 41. The horizontal axis (class) of the histogram is obtained by dividing various road gradients on which the vehicle has traveled into predetermined regions centering on flat road = 0, and the vertical axis (frequency) is the region for each road gradient region. Total distance.

  FIG. 3 shows a relationship diagram between the standard deviation σ and the energy related to traveling of the vehicle. As shown in the figure, as the value of the standard deviation σ increases, the frequency of traveling at a high gradient increases, so the proportion of potential energy increases, and the energy required for traveling increases accordingly. Part of the potential energy is energy that cannot be regenerated due to loss of power generation efficiency or the like by the motor 3 (non-regenerative energy), and the portion of the positional energy excluding the non-regenerative energy is regenerative energy. As described above, the standard deviation σ becomes an index indicating the magnitude of travel energy for a predetermined travel distance and a potential energy index indicating the magnitude of potential energy.

  The conversion efficiency calculation unit 43 is based on the power history for a predetermined travel distance stored in the storage unit 41, and converts the power conversion efficiency per unit time in the section of the predetermined travel distance, that is, the average conversion efficiency (hereinafter referred to as conversion). (Referred to as efficiency η). Specifically, the conversion efficiency η is calculated from (the work of the motor 3) / (the work of the battery 11) at a predetermined travel distance.

  The energy recovery mode selection unit 44 selects an energy recovery mode based on the standard deviation σ and the conversion efficiency η. Here, the relationship between the energy recovery modes will be described in detail based on the explanatory diagram showing the energy recovery amount corresponding to the standard deviation σ and the conversion efficiency η (0 ≦ η <1) shown in FIG.

  In FIG. 4, when the standard deviation σ is (a) small, (b) is in middle, and (c) is large, each of three patterns of roads when traveling in the vehicle speed priority mode and the regeneration priority mode, respectively. The amount of energy recovery is shown. As shown in FIGS. 4 (a) and 4 (b), when the standard deviation σ is small or medium, energy recovery in the vehicle speed priority mode and the regeneration priority mode with a predetermined conversion efficiency ηa (hereinafter referred to as the predetermined efficiency ηa) as a boundary. The superiority of the quantity is reversed. That is, when the conversion efficiency η is less than the predetermined efficiency ηa, the energy regeneration amount is larger in the vehicle speed priority mode, and in the regeneration priority mode, the energy regeneration amount is larger than the predetermined efficiency ηa.

  As shown in FIGS. 4A and 4B, the predetermined efficiency ηa increases as the standard deviation σ increases. When the standard deviation σ is large as shown in FIG. 4 (c), the predetermined efficiency ηa becomes a value close to 1, so that even if the conversion efficiency η changes, the vehicle speed priority mode and the regeneration priority mode are superior or inferior. Without reversing, the regeneration amount in the vehicle speed priority mode is always greater than the regeneration amount in the regeneration priority mode.

  The energy recovery mode selection unit 44 selects an energy recovery mode based on the relationship between the standard deviation σ and the conversion efficiency η.

  Here, FIG. 4 shows a flowchart of the energy recovery control routine on the downhill road that is executed in the vehicle ECU 13 when the predictive control is impossible, and will be described below based on the flowchart.

  First, vehicle ECU13 discriminate | determines whether prediction control is possible as step S1. When the determination result is true (Yes), that is, when the navigation device 31 and the communication device 32 can normally acquire various information, the vehicle speed increase control based on the prediction control and the regeneration control of the motor 3 should be performed on the downhill road. The routine ends. On the other hand, if the determination result is false (No), that is, if the navigation device 31 and the communication device 32 cannot normally acquire various information, the process proceeds to step S2.

  In step S <b> 2, the vehicle ECU 13 stores the road gradient information detected by the gradient sensor 33 and the power information input / output by the motor 3 and the battery 11 detected by the inverter ECU 23 in the storage unit 41. Update history to the latest information.

  In subsequent step S3, the standard deviation calculation unit 42 calculates the standard deviation σ at a predetermined travel distance based on the gradient history, and the conversion efficiency calculation unit 43 calculates the conversion efficiency η at a predetermined travel distance based on the power history. .

  In step S4, the energy recovery mode selection unit 44 determines whether the standard deviation σ is equal to or greater than a predetermined value σa. If the determination result is false (No), that is, if the vehicle is traveling on a road having a relatively small standard deviation σ as shown in FIGS.

  In step S5, the energy recovery mode selection unit 44 determines whether or not the conversion efficiency η is equal to or higher than a predetermined efficiency ηa. If the determination result is true (Yes), that is, if the conversion efficiency η is relatively large, the process proceeds to step S6.

  In step S6, the energy recovery mode selection unit 44 selects the regeneration priority mode as the energy recovery mode, and proceeds to step S7.

  On the other hand, when the determination result in step S4 is true (Yes), that is, when the standard deviation σ is greater than or equal to the predetermined value σa, the vehicle 1 has a relatively large standard deviation σ as shown in FIG. Driving on the road, the process proceeds to step S8. If the determination result in step S5 is false (No), that is, if the standard deviation σ is less than the predetermined value σa and the conversion efficiency η is less than the predetermined efficiency ηa, the process proceeds to step S8.

  In step S8, the energy recovery mode selection unit 44 selects the vehicle speed priority mode as the energy recovery mode, and proceeds to step S7.

  In step S7, the auto-cruise control unit 40 controls the engine 2, the motor 3, and the brake device 34 in accordance with the energy recovery mode selected in step S6 or S8 on the downhill road, and returns the routine.

  Specifically, when the vehicle speed priority mode is selected by the energy recovery mode selection unit 44, the auto-cruise control unit 40 first starts the vehicle speed increase control when reaching the downhill road. Specifically, the clutch 4 is disconnected to keep the torque of the motor 3 at 0, or the clutch 4 is connected and gear neutral is used to speed up the vehicle 1 in a coasting state. Then, when the vehicle speed V reaches the upper limit speed VHi of the set vehicle speed range, the vehicle speed increase control is terminated and the regeneration control of the motor 3 is started. Specifically, the regeneration control in this case is to regenerate the motor 3 with a negative torque necessary to maintain the vehicle speed V, and to maintain the vehicle speed V even when the motor 3 is regenerated at the maximum output. When the side torque is insufficient, the braking device 34 is operated. This operation state is continued until the SOC of the battery 11 reaches the upper limit or until the end of the downhill road.

  On the other hand, when the regeneration priority mode is selected, the auto cruise control unit 40 first starts the regeneration control of the motor 3 when it reaches the downhill road. Specifically, the motor 3 is regenerated with a desired output. The output of the motor 3 is not particularly limited as long as the vehicle speed can be maintained (in other words, as long as the vehicle speed does not decrease), and may be the maximum output or the negative side that is the minimum necessary for maintaining the vehicle speed. Torque may be used. Then, when the battery 11 reaches the upper limit of the SOC, the regeneration control is terminated, and the vehicle speed increase control is started. Specifically, the vehicle speed increase control here is the upper limit speed of the vehicle speed range in which the vehicle speed V is set with the clutch 4 disconnected and the motor torque kept at 0, or the clutch 4 connected and the gear in the neutral state. This operating state is continued until VHi is reached or until the end of the downhill road.

  The end of the downhill road may be determined from, for example, a road gradient detected by the gradient sensor 33 or may be determined based on other information.

  As described above, in the auto-cruise control in the hybrid truck according to the present embodiment, the tendency of the potential energy on the road on which the host vehicle 1 is traveling is estimated by the standard deviation σ based on the gradient history, and the motor 3 and the battery 11 are used. Whether to give priority to vehicle speed increase control or regenerative control of the motor 3 is selected from the conversion efficiency η based on the input / output power history.

  Since this is based on the gradient history and the power history at a predetermined travel distance, it does not require predictive control using the navigation device 31 or the communication device 32, and does not need to process a large amount of information, and is an efficient energy recovery mode. Can be selected appropriately.

  In particular, by obtaining the standard deviation σ based on the gradient history as an index of potential energy, the index of potential energy can be easily calculated. In addition, by considering the power conversion efficiency η between the motor 3 and the battery 11, an energy recovery mode suitable for the state of the motor 3 and the battery 11 can be selected.

  The potential energy can be efficiently recovered into kinetic energy and electric power energy by traveling on the downhill road in the energy recovery mode selected in this way.

  Thereby, vehicle ECU13 in this embodiment can improve the recovery efficiency of energy by a simple method, without requiring acquisition and processing of information by navigation device 31 and communication device 32.

  Although the description of the embodiment of the control apparatus for an electric vehicle according to the present invention is finished above, the embodiment is not limited to the above embodiment.

  The vehicle 1 according to the above embodiment is a hybrid truck including an engine 2 and a motor 3 as drive sources, but an electric vehicle to which the present invention can be applied is not limited thereto. For example, an electric vehicle including only a motor as a drive source may be used. The present invention can also be applied to passenger cars instead of trucks.

  Moreover, in the said embodiment, although the road gradient is detected by the gradient sensor 33, the detection of a road gradient may be calculated from other information instead of the detection by a sensor.

  Moreover, although the vehicle 1 in the said embodiment is provided with the navigation apparatus and communication apparatus containing GPS, this invention is applied also to the vehicle which is not equipped with such a navigation apparatus and communication apparatus and cannot perform predictive control in the first place. can do.

1 Vehicle 2 Engine 3 Motor 13 Vehicle ECU
23 Inverter ECU (electric power detection means)
31 Navigation device 32 Communication device 33 Gradient sensor (gradient detection means)
34 Braking device (braking means)
40 Auto cruise control unit (auto cruise control means)
41 Storage unit (storage means)
42 Standard deviation calculation unit (index calculation means)
43 Conversion efficiency calculation unit (conversion efficiency calculation means)
44 Energy recovery mode selection unit (energy recovery mode selection means)

Claims (1)

Drive means including an electric motor that is a drive source of the vehicle and can generate electricity and charge the battery;
Braking means for braking the vehicle;
Auto cruise control means for controlling the drive means and the braking means to execute auto cruise control for running the vehicle while maintaining the vehicle speed within a set vehicle speed range;
Slope detecting means for detecting the road slope on which the host vehicle is traveling;
Electric power detection means for detecting electric power input and output by the electric motor and the battery;
Storage means for storing the road gradient detected by the gradient detection means and the power detected by the power detection means;
Index calculation means for calculating a potential energy index indicating the magnitude of potential energy in a predetermined section based on the history of road gradient stored in the storage means;
Conversion efficiency calculation means for calculating the power conversion efficiency in the predetermined section based on the power history stored in the storage means;
As energy recovery mode on downhill road,
When the potential energy index calculated by the index calculation means is greater than or equal to a predetermined value, or when the potential energy index is less than a predetermined value and the conversion efficiency calculated by the conversion efficiency calculation means is greater than or equal to a predetermined efficiency To select a vehicle speed priority mode for performing regeneration control of the electric motor after increasing the vehicle speed to the upper limit of the vehicle speed range,
When the potential energy index is less than the predetermined value and the conversion efficiency is less than the predetermined efficiency, the vehicle speed range is set after performing regeneration control of the electric motor until the charge amount of the battery becomes a predetermined charge amount. Energy recovery mode selection means for selecting a regeneration priority mode for increasing the vehicle speed at
The auto cruise control means is a control device for an electric vehicle that controls the drive means and the braking means in accordance with an energy recovery mode selected by the energy recovery mode selection means on a downhill road.

Images