JP6693322B2 - Electric vehicle - Google Patents

Description

  The present invention relates to an electric vehicle, and more particularly, to an electric vehicle configured to be able to execute regenerative expansion control.

  BACKGROUND ART Conventionally, various controls have been developed to support energy-saving driving of electric vehicles by users. One of them is called regenerative expansion control (see Patent Document 1). The regenerative expansion control is a point at which the vehicle is predicted to stop or decelerate ahead of the travel route of the vehicle when the vehicle is predicted to stop or decelerate while the vehicle is traveling (hereinafter referred to as “target stop deceleration position”). "), There is a control for increasing the deceleration due to regeneration during inertial running of the vehicle (state in which the vehicle is running with inertia without generating driving force). By executing the regenerative expansion control, the regenerative power generation amount during coasting before reaching the target stop deceleration position is increased more than usual, so the regenerative energy is missed (the kinetic energy is lost due to the operation of the friction brake, etc.). Occurrence of situation where part is converted to heat and is discarded) is suppressed.

JP, 2014-110677, A JP2012-116428A

  However, in addition to the above-described regenerative expansion control, there is also control called free-run control as control for supporting energy-saving driving of an electric vehicle. The free-run control is a control that reduces the deceleration due to regeneration during coasting of the vehicle. By executing the free-run control, the deceleration due to regeneration during coasting becomes a lower level than usual, so the coasting distance can be extended.

  Free-run control and regenerative expansion control are common in that they support energy-saving operation.However, free-run control reduces regenerative power generation during coasting, whereas regenerative expansion control regenerates power during coasting. Both are contradictory controls in terms of increasing the amount. Therefore, in an electric vehicle that is configured to be able to selectively execute both, there may be a case where the loss of regenerative energy cannot be appropriately suppressed. Specifically, if one of the free-run control and the regenerative expansion control is executed while the other is requested, if the free-run control is executed without executing the regenerative expansion control, the vehicle will stop or decelerate. Although it is predicted that the regenerative power generation amount cannot be increased, the regenerative energy may be missed.

  The present invention has been made to solve the above-described problems, and an object thereof is to stop or decelerate an electric vehicle in an electric vehicle configured to be able to selectively execute free-run control and regenerative expansion control. It is to appropriately suppress the loss of the regenerative energy when is predicted.

An electric vehicle according to the present disclosure includes a rotating electric machine connected to driving wheels of the vehicle, and a control device configured to selectively execute free-run control and regeneration expansion control. The free run control is a control for reducing the deceleration due to the regeneration of the rotating electric machine during the coasting of the vehicle as compared with the case where the free run control is not executed. The regenerative expansion control sets a point where the vehicle is predicted to stop or a point where the vehicle is predicted to decelerate ahead of the travel route of the vehicle, and when the vehicle is predicted to stop or decelerate while the vehicle is traveling, Is a control for increasing the deceleration due to the regeneration of the rotating electric machine during the coasting of the vehicle as compared with the case where the regeneration expansion control is not executed. The control device executes the regenerative expansion control without executing the free-run control when the other request is issued during execution of one of the free run control and the regenerative expansion control.

  According to the above configuration, when one of the free run control and the regenerative expansion control is executed while the other is requested, the regenerative expansion control is executed instead of the free run control. Therefore, the regenerative power generation amount can be appropriately increased in the situation where the stop or deceleration of the electric vehicle is predicted. As a result, in the electric vehicle configured to selectively execute the free-run control and the regenerative expansion control, it is possible to appropriately suppress the loss of the regenerative energy when the stop or deceleration of the electric vehicle is predicted.

It is a whole block diagram of a vehicle. It is a figure which shows typically an example of the change of the vehicle speed and the deceleration level when the pre-reading deceleration control is performed. It is a figure which shows an example of the functional block of a control apparatus typically. It is a figure which shows an example of an arbitration result. It is a figure which shows the other example of a mediation result. It is a flow chart which shows an example of a processing procedure of a control device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference characters and description thereof will not be repeated.

  FIG. 1 is an overall block diagram of a vehicle 1 according to the present embodiment. The vehicle 1 includes an engine 10, a first motor generator (hereinafter also referred to as “first MG”) 20, a second motor generator (hereinafter also referred to as “second MG”) 30, a power split device 40, and a PCU (Power Control). Unit) 50, a battery 60, a drive wheel 80, a friction brake generation circuit 90, and an ECU (Electronic Control Unit) 100.

  Vehicle 1 is a hybrid vehicle that travels with at least one of the power of engine 10 and the power of second MG 30. In the present embodiment, an example in which the present disclosure is applied to a hybrid vehicle is shown, but a vehicle to which the present disclosure can be applied may be an electric vehicle that includes at least a motor generator for traveling, and is limited to a hybrid vehicle. Not done.

  Power generated by engine 10 is split by power split device 40 into a route that is transmitted to drive wheels 80 and a route that is transmitted to first MG 20.

  First MG 20 and second MG 30 are three-phase AC rotating electric machines driven by PCU 50. The first MG 20 uses the power of the engine 10 split by the power split device 40 to generate power.

  Second MG 30 generates the driving force of vehicle 1 using at least one of the electric power stored in battery 60 and the electric power generated by first MG 20. In addition, the second MG 30 regeneratively generates electric power using the kinetic energy of the vehicle 1 transmitted from the drive wheels 80 during inertial running in the accelerator off state (a state in which the user does not step on the accelerator pedal). The regenerative power generated by the second MG 30 is recovered by the battery 60.

  The power split device 40 is a planetary gear mechanism that includes a sun gear, a pinion gear, a carrier, and a ring gear. The pinion gear meshes with each of the sun gear and the ring gear. The carrier rotatably supports the pinion gear and is connected to the crankshaft of the engine 10. The sun gear is coupled to the rotation shaft of first MG 20. The ring gear is connected to the rotation shaft of second MG 30 and drive wheel 80.

  PCU 50 converts the DC power stored in battery 60 into AC power capable of driving first MG 20 and second MG 30. Further, PCU 50 converts the AC power generated by first MG 20 and second MG 30 into DC power with which battery 60 can be charged.

  The battery 60 is configured to include, for example, nickel hydrogen, lithium ion, or the like. Battery 60 is charged with electric power generated by at least one of first MG 20 and second MG 30.

  The friction brake generation circuit 90 supplies the brake fluid pressure corresponding to the control signal from the ECU 100 to the brake caliper 91. As a result, the brake pad (not shown) is pressed against the brake disc 92, and the rotation of the brake disc 92 is restricted by the friction generated between the brake pad and the brake pad. As a result, the kinetic energy of the vehicle 1 is converted into heat and a friction brake is generated.

  Further, the vehicle 1 includes an accelerator pedal sensor 2, a brake pedal sensor 3, a shift sensor 4, a navigation device 5, a road-vehicle communication device 6, and an HMI (Human Machine Interface) device 7. The accelerator pedal sensor 2 detects an accelerator pedal operation amount (hereinafter, also referred to as “accelerator opening degree”) ACC by a user. The brake pedal sensor 3 detects the brake pedal operation amount BP by the user. The shift sensor 4 detects the shift lever position SP operated by the user. These sensors output the detection result to the ECU 100.

  The navigation device 5 includes GPS (Global Positioning System) and map data. The navigation device 5 calculates the vehicle position information by GPS, the road shape information around the vehicle position obtained by referring to the map data, the traveling route information set by the user, and outputs the calculated information to the ECU 100.

  Further, the navigation device 5 accumulates information on the position where the vehicle 1 has decelerated and stopped in the past, and learns the stop position and the decelerated position of the vehicle 1 from the history. The navigation device 5 outputs the learned stop position and deceleration position (hereinafter also referred to as “stop deceleration learning position”) to the ECU 100. Note that the stop deceleration position may be learned by the ECU 100 based on the information from the navigation device 5.

  The road-to-vehicle communication device 6 communicates with a roadside device (a radio wave media such as an optical beacon) installed on a road or a traffic signal to thereby obtain signal information (signal cycle) around the vehicle, road alignment information, and road information. Infrastructure information such as traffic information (congestion information, regulation information) is acquired, and the acquired information is output to the ECU 100.

  The HMI device 7 is a device that provides a user with information for supporting driving of the vehicle 1. The HMI device 7 includes, for example, a display (visual information display device), a speaker (auditory information output device), and the like provided inside the vehicle 1. The HMI device 7 provides various information to the user by outputting visual information (graphic information, character information), auditory information (voice information, sound information) and the like. As the HMI device 7, another existing device, for example, a display or a speaker of the navigation device 5 may be diverted. Further, the HMI device 7 may be configured to include a tactile information output device that outputs tactile information such as steering wheel vibration, seat vibration, and pedal reaction force.

  Further, although not shown, the vehicle 1 has various physical quantities necessary for controlling the vehicle 1, such as a vehicle speed sensor for detecting the vehicle speed and a monitoring sensor for detecting the state of the battery 60 (voltage, current, temperature, etc.). It has a plurality of sensors for detecting. Each of these sensors outputs the detection result to the ECU 100.

  The ECU 100 has a CPU (Central Processing Unit) and a memory (not shown) built therein, and executes predetermined arithmetic processing based on information stored in the memory and information from each sensor. The ECU 100 controls each device such as the engine 10, the PCU 50, the friction brake generation circuit 90, and the HMI device 7 based on the result of the arithmetic processing.

  For example, when the user depresses (operates) the accelerator pedal, ECU 100 calculates the required driving force from accelerator opening ACC, vehicle speed, and the like, and engine 10 and first MG 20 are calculated so as to satisfy the required driving force. And controlling the output of the second MG 30.

  When the user depresses (operates) the brake pedal, the ECU 100 calculates the required braking force from the brake pedal operation amount BP, the vehicle speed, etc., and regenerative braking force and friction to satisfy the required braking force. Control the braking force.

<Free run control and regenerative expansion control>
The ECU 100 selectively executes free-run control and regenerative expansion control as controls for supporting energy-saving driving of the vehicle 1.

  The free-run control is control for reducing the deceleration due to regeneration during coasting in the accelerator off state and the brake off state. By executing the free-run control, the deceleration due to regeneration during coasting becomes a lower level than usual, so the coasting distance can be extended.

  The regenerative expansion control is, when the vehicle is predicted to stop or decelerate while the vehicle 1 is traveling, specifically, a point at which the vehicle 1 is predicted to stop in front of the traveling route of the vehicle 1 (hereinafter, “target stop position” ") Or a point predicted to decelerate (hereinafter also referred to as" target deceleration position ") is control for increasing deceleration due to regeneration during inertial running in the accelerator off state. By executing the regenerative expansion control, the regenerative power generation amount during coasting before reaching the target stop position or the target deceleration position (hereinafter also referred to as the “target stop deceleration position”) is increased more than usual, and thus the regenerative power generation is performed. Occurrence of loss of energy (a situation in which a part of the kinetic energy of the vehicle 1 is converted to heat or the like and discarded due to the operation of the friction brake) is suppressed.

  In the present embodiment, ECU 100 sets a target stop deceleration position based on information from navigation device 5 and road-vehicle communication device 6. Specifically, the ECU 100 determines whether there is a stop deceleration learning position in front of the traveling route of the vehicle 1 based on the information from the navigation device 5, and if there is a stop deceleration learning position, the learning position is determined. To the target stop deceleration position. Further, the ECU 100 receives the signal cycle of the intersection from the roadside device installed at the intersection ahead of the travel route by using the road-vehicle communication device 6, and predicts that the vehicle 1 stops at the intersection from the received signal cycle. If so, the intersection is set to the target stop deceleration position. The method of setting the target stop deceleration position is not limited to the above. For example, when the vehicle 1 is provided with a device (camera, radar, etc.) that detects a vehicle-to-vehicle distance and a relative acceleration with respect to a vehicle ahead, the vehicle 1 is decelerated when it is predicted that the vehicle will decelerate based on the information from the device. Then, the predicted point can be set as the target deceleration position.

  The ECU 100 according to the present embodiment uses the HMI device 7 to notify the user of guidance for guiding the accelerator off operation (operation of stopping the depression of the accelerator pedal) to the user before executing the regenerative expansion control. Control (hereinafter referred to as "accelerator off guide control") is started. Hereinafter, the accelerator-off guidance control and the regenerative expansion control will be collectively referred to as "prefetch deceleration control".

  FIG. 2 is a diagram schematically showing an example of changes in the vehicle speed and the deceleration level when the prefetch deceleration control is executed. In FIG. 2, the horizontal axis indicates the travel distance (travel position), the upper vertical axis indicates the vehicle speed, and the lower vertical axis indicates the deceleration level. Further, in FIG. 2, an example of change when the prefetch deceleration control is executed is shown by a solid line, and an example of change when the readahead deceleration control is not executed is shown by a dashed line.

  FIG. 2 shows an example in which it is determined that the target stop position is at the position D6 ahead of the travel route. The target stop position is calculated based on the information from the navigation device 5 and the road-vehicle communication device 6 as described above. Examples of the target stop position include an intersection, a pedestrian crossing point, a T-shaped road, and a temporary stop line.

  When the vehicle 1 reaches the predetermined position D1 before the travel route from the target stop position D6, the ECU 100 determines the optimum start position D4 for starting the regeneration expansion control from the vehicle speed at that time and the remaining distance to the target stop position D6. calculate.

  The ECU 100 starts the above-mentioned accelerator-off guidance control when the vehicle 1 reaches the predetermined position D2, which is located before the travel route, from the calculated start position D4. When the user who notices this guidance performs an accelerator off operation, normal regeneration is started. The normal regeneration is regenerative control during coasting in the accelerator off state and when regenerative expansion control is not executed.

  After that, when the vehicle 1 reaches the start position D4, the ECU 100 starts the above-described regenerative expansion control. In the regenerative expansion control, the deceleration (regenerative power generation amount) due to the regenerative power is increased more than in the normal regenerative power control. Therefore, more regenerative energy is recovered than when normal regeneration is continued.

  Thereafter, when the user performs a brake-on operation (operation of depressing the brake pedal) when the vehicle 1 reaches the predetermined position D5, the friction braking force is applied and the vehicle 1 is stopped at the target stop position D6.

  When the prefetch deceleration control is not executed (dashed line), the accelerator off guidance control is not executed, and therefore, when the prefetch deceleration control is executed at the timing (position D3) at which the user performs the accelerator off operation (position D2). ) Will be later than. Furthermore, even during coasting after the accelerator off operation, normal regeneration is performed instead of regeneration extension control. Therefore, the regenerative energy cannot be sufficiently collected by the time when the user performs the brake-on operation (position D5), and the regenerative energy is missed. On the other hand, in the present embodiment, the prefetch deceleration control described above is executed, so that the occurrence of missing regenerative energy is suppressed.

<Selection of free-run control and regenerative expansion control>
The free-run control and the regenerative expansion control described above are common in that they support energy-saving operation, but the free-run control reduces the regenerative power generation amount during coasting, whereas the regenerative expansion control reduces the regenerative power generation during coasting. In terms of increasing the amount of regenerative power generation, the two control are contradictory.

  Therefore, in the vehicle 1 configured so that both of them can be selectively executed, it may not be possible to appropriately suppress the loss of regenerative energy. Specifically, if regenerative expansion control is requested during execution of free-run control, or if free-run control is requested during execution of regenerative expansion control, free-run control is not executed and free-run control is executed. If the control is executed, it is feared that the regenerative power generation amount cannot be increased and the regenerative energy may be missed even though the vehicle 1 is predicted to be stopped or decelerated.

  Therefore, the ECU 100 according to the present embodiment executes the regenerative expansion control instead of the free-run control when one of the free run control and the regenerative expansion control is executed while the other is requested. As a result, in a situation where the vehicle 1 is predicted to be stopped or decelerated, the regenerative power generation amount can be appropriately increased, and the loss of regenerative energy can be appropriately suppressed.

  FIG. 3 is a diagram schematically showing an example of functional blocks of ECU 100 according to the present embodiment. ECU 100 includes a free-run control unit 110 that substantially performs the above-mentioned free-run control, a prefetch deceleration control unit 120, and an arbitration unit 130.

  The prefetch deceleration control unit 120 includes a guidance control unit 121 that performs the above-described accelerator-off guidance control, and a regenerative expansion control unit 122 that substantially performs the regenerative expansion control.

  The arbitration unit 130 is connected to the free-run control unit 110 and the regenerative expansion control unit 122, and performs arbitration when one of the free-run control and the regenerative expansion control is executed while the other is requested. Specifically, when the free-run control and the regenerative expansion control overlap, the arbitration unit 130 preferentially operates the regenerative expansion control over the free-run control.

  FIG. 4 is a diagram illustrating an example of an arbitration result by the arbitration unit 130. In the example shown in FIG. 4, the regenerative expansion request (regeneration expansion control request) changes from off to on at position D11 during free-run control. In this case, the arbitration unit 130 stops the free-run control and executes the regenerative expansion control.

  FIG. 5 is a diagram showing another example of the arbitration result by the arbitration unit 130. In the example shown in FIG. 5, the free-run request (request for free-run control) changes from OFF to ON at position D21 during the regenerative expansion control. In this case, the arbitration unit 130 does not execute the free-run control but continues the execution of the regenerative expansion control.

  FIG. 6 is a flowchart showing an example of a processing procedure performed when the ECU 100 realizes the above function. This flowchart is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as “S”) 10, ECU 100 determines whether or not the regenerative expansion request changes from off to on.

  When the regenerative expansion request changes from OFF to ON (YES in S10), ECU 100 determines in S20 whether or not the free-run control is being performed.

  If the free-run control is being performed (YES in S20), the ECU 100 stops the free-run control in S21, and then starts executing the regenerative expansion control in S22. If the free-run control is not being performed (NO in S20), ECU 100 directly executes the regenerative expansion control in S22.

  When the regenerative expansion request has not changed from OFF to ON (NO in S10), ECU 100 determines in S30 whether the free-run request has changed from OFF to ON.

  When the free-run request changes from OFF to ON (YES in S30), ECU 100 determines in S31 whether or not regenerative expansion control is being performed.

  If regenerative expansion control is being performed (YES in S31), ECU 100 rejects the free-run request in S32 and does not execute free-run control, and continues execution of regenerative expansion control in S22. If the regeneration expansion control is not being performed (NO in S31), ECU 100 executes free-run control in S32.

  As described above, ECU 100 according to the present embodiment executes the regenerative expansion control instead of the free-run control when one of the free run control and the regenerative expansion control is requested while the other is requested. As a result, in a situation where the vehicle 1 is predicted to be stopped or decelerated, the regenerative power generation amount can be appropriately increased, and the loss of regenerative energy can be appropriately suppressed.

  The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

  1 vehicle, 2 accelerator pedal sensor, 3 brake pedal sensor, 4 shift sensor, 5 navigation device, 6 road vehicle-to-vehicle communication device, 7 HMI device, 10 engine, 20 1 MG, 30 2 MG, 40 power split device, 60 battery, 80 drive wheels, 90 friction brake generation circuit, 91 brake caliper, 92 brake disc, 100 control device, 110 free-run control unit, 120 look-ahead deceleration control unit, 121 guidance control unit, 122 regenerative expansion control unit, 130 arbitration unit.

Claims (1)

A rotating electric machine connected to the drive wheels of the vehicle,
And a controller configured to selectively execute free-run control and regenerative expansion control,
The free-run control is a control for reducing the deceleration due to the regeneration of the rotating electric machine during coasting of the vehicle, as compared with the case where the free-run control is not executed,
In the regenerative expansion control, a point predicted to stop the vehicle or a point predicted to decelerate is set in front of the traveling route of the vehicle, and the stop or deceleration of the vehicle is predicted while the vehicle is traveling. In the case of, the deceleration due to regeneration of the rotating electric machine during coasting of the vehicle is a control for increasing the deceleration as compared with the case where the regeneration expansion control is not executed,
The control device executes the regenerative expansion control without executing the free-run control when the other request is issued during execution of one of the free run control and the regenerative expansion control.

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