JP2018019479A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly suppress missing of regeneration energy when stop or deceleration of a vehicle is predicted, in an electric vehicle selectively performing free-run control and regenerative expansion control.SOLUTION: An electric vehicle includes: a motor generator for travelling; and an ECU structured so as to selectively perform free-run control and regenerative expansion control. The free-run control is such as to reduce deceleration due to regeneration of a motor generator during inertia traveling. The regenerative expansion control is such as to increase deceleration due to regeneration of the motor generator during inertia traveling when stop or deceleration of the vehicle is predicted during travelling of the vehicle. The ECU performs the regenerative expansion control without performing the free-run control when the regenerative expansion control is requested during the free-run control, or the free-run control is requested during the regenerative expansion control.SELECTED DRAWING: Figure 6

Description

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

  Conventionally, various controls have been developed to support energy-saving operation of an electric vehicle by a user. One of them is called regeneration expansion control (see Patent Document 1). In the regeneration expansion control, when the vehicle is predicted to stop or decelerate while the vehicle is traveling, specifically, a point where the vehicle is predicted to stop or decelerate ahead of the vehicle travel path (hereinafter referred to as “target stop deceleration position”). ”) Is a control for increasing the deceleration due to regeneration during inertial traveling of the vehicle (the vehicle is traveling with inertia without generating a driving force). By executing the regeneration expansion control, the amount of regenerative power generation during inertial driving before reaching the target stop deceleration position is increased more than usual. Occurrence of a situation where the part is converted into heat and discarded.

JP 2014-110777 A JP 2012-116428 A

  However, as control for supporting energy saving operation of an electric vehicle, there is what is called free-run control in addition to the above-described regeneration expansion control. Free-run control is control that reduces deceleration due to regeneration during inertial running of the vehicle. By executing the free-run control, the deceleration due to regeneration during inertial traveling is at a level lower than usual, so that the inertial traveling distance can be extended.

  Free-run control and regenerative expansion control are common in that they support energy-saving operation, while free-run control reduces the amount of regenerative power generation during coasting, whereas regenerative expansion control is regenerative power generation during coasting In terms of increasing the amount, both are contradictory controls. Therefore, in an electric vehicle configured to be able to selectively execute both, there may be a case where it is not possible to appropriately prevent the regeneration energy from being overlooked. Specifically, when one of the free run control and the regeneration expansion control is requested and the other is requested, if the free run control is performed without executing the regeneration expansion control, the vehicle is stopped or decelerated. However, there is a concern that the amount of regenerative power generation cannot be increased, but regenerative energy is lost.

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

  An electric vehicle according to the present disclosure includes a rotating electrical machine connected to a drive wheel 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 that reduces the deceleration due to regeneration of the rotating electrical machine during inertial running of the vehicle as compared with the case where the free-run control is not executed. Regenerative expansion control is a control that increases the deceleration due to regeneration of the rotating electrical machine during inertial traveling of the vehicle when the vehicle is predicted to stop or decelerate while the vehicle is traveling compared to when the regeneration expansion control is not performed. is there. When there is a request for the other during execution of one of the free run control and the regeneration expansion control, the control device executes the regeneration expansion control without executing the free run control.

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

1 is an overall block diagram of a vehicle. It is a figure which shows typically an example of the change of the vehicle speed and deceleration level in case pre-reading deceleration control is performed. It is a figure which shows typically an example of the functional block of a control apparatus. It is a figure which shows an example of a mediation result. It is a figure which shows the other example of the mediation result. It is a flowchart which shows an example of the process sequence of a control apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals 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, a PCU (Power Control). Unit) 50, battery 60, drive wheel 80, friction brake generating circuit 90, and ECU (Electronic Control Unit) 100.

  Vehicle 1 is a hybrid vehicle that travels by 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. However, a vehicle to which the present disclosure is applicable may be an electric vehicle including at least a motor generator for traveling, and is limited to a hybrid vehicle. Not.

  The power generated by the engine 10 is divided by the power split device 40 into a path transmitted to the drive wheels 80 and a path transmitted to the first MG 20.

  First MG 20 and second MG 30 are three-phase AC rotating electric machines driven by PCU 50. First MG 20 generates power using the power of engine 10 divided by power split device 40.

  Second MG 30 generates driving force for vehicle 1 using at least one of the electric power stored in battery 60 and the electric power generated by first MG 20. Further, second MG 30 performs regenerative power generation using the kinetic energy of vehicle 1 transmitted from drive wheels 80 during inertial running in the accelerator-off state (the user is not stepping on the accelerator pedal). The regenerative power generated by the second MG 30 is collected by the battery 60.

  Power split device 40 is a planetary gear mechanism including 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 supports the pinion gear so as to be able to rotate and is coupled to the crankshaft of the engine 10. The sun gear is connected to the rotation shaft of the 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 that can drive first MG 20 and second MG 30. The PCU 50 converts AC power generated by the first MG 20 and the second MG 30 into DC power that can charge the battery 60.

  The battery 60 includes, for example, nickel metal hydride, lithium ions, and 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 a brake hydraulic pressure corresponding to a control signal from the ECU 100 to the brake caliper 91. As a result, a brake pad (not shown) is pressed against the brake disc 92, and the rotation of the brake disc 92 is restricted by friction generated between the brake pad and the brake disc 92. Thereby, the kinetic energy of the vehicle 1 is converted into heat and a friction brake is generated.

  The vehicle 1 further includes an accelerator pedal sensor 2, a brake pedal sensor 3, a shift sensor 4, a navigation device 5, a road-to-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”) ACC by the user. The brake pedal sensor 3 detects a 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 travel route information set by the user, etc., and outputs them to the ECU 100.

  Moreover, the navigation apparatus 5 accumulate | stores the information of the position where the vehicle 1 decelerated in the past, and the position where it stopped, and learns the stop position and deceleration position of the vehicle 1 from the log | 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 learning of the stop deceleration position may be performed by the ECU 100 based on information from the navigation device 5.

  The road-to-vehicle communication device 6 communicates with roadside devices (radio wave media such as optical beacons) installed on roads, traffic lights, etc., so that signal information (signal cycle) around the vehicle, road alignment information, roads 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) and a speaker (auditory information output device) provided in 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, other existing devices, for example, a display or a speaker of the navigation device 5 may be used. The HMI device 7 may include a haptic information output device that outputs haptic information such as steering wheel vibration, seat vibration, pedal reaction force, and the like.

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

  The ECU 100 includes a CPU (Central Processing Unit) and a memory (not shown), 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, the ECU 100 calculates the required driving force from the accelerator opening ACC and the vehicle speed when the user is stepping on (operating) the accelerator pedal, and the engine 10 and the first MG 20 so as to satisfy the required driving force. And the output of 2nd MG30 is controlled.

  In addition, when the user steps on (operates) the brake pedal, the ECU 100 calculates the required brake force from the brake pedal operation amount BP and the vehicle speed, and the regenerative brake force and friction so as to satisfy the required brake force. Control the braking force.

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

  Free-run control is control that reduces deceleration due to regeneration during inertial running in the accelerator-off state and the brake-off state. By executing the free-run control, the deceleration due to regeneration during inertial traveling is at a level lower than usual, so that the inertial traveling distance can be extended.

  In the regeneration expansion control, when the vehicle is predicted to stop or decelerate while the vehicle 1 is traveling, specifically, a point where the vehicle 1 is predicted to stop in front of the travel route of the vehicle 1 (hereinafter referred to as “target stop position”). Or a point predicted to decelerate (hereinafter also referred to as “target deceleration position”), the control is to increase the deceleration due to regeneration during inertial running in the accelerator off state. By executing the regeneration expansion control, the amount of regenerative power generation during inertial driving before reaching the target stop position or target deceleration position (hereinafter also referred to as “target stop deceleration position”) is increased more than usual. Occurrence of energy loss (a situation where a part of the kinetic energy of the vehicle 1 is converted into heat or the like by the operation of a friction brake or the like) is suppressed.

  In the present embodiment, ECU 100 sets a target stop deceleration position based on information from navigation device 5 and road-to-vehicle communication device 6. Specifically, the ECU 100 determines whether or not there is a stop deceleration learning position in front of the travel route of the vehicle 1 based on information from the navigation device 5, and if there is a stop deceleration learning position, the learning position To the target stop deceleration position. Further, the ECU 100 receives a signal cycle at the intersection from a roadside device installed at an intersection in front of the travel route using the road-to-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 for setting the target stop deceleration position is not limited to the above. For example, when the vehicle 1 includes a device (camera, radar, or the like) that detects the inter-vehicle distance or relative acceleration with the preceding vehicle, the vehicle is decelerated when the vehicle is predicted to decelerate based on information from the device. Then, the predicted point can be set as the target deceleration position.

  The ECU 100 according to the present embodiment notifies the user using the HMI device 7 of guidance for guiding the accelerator off operation (operation for stopping the accelerator pedal) to the user before the regeneration expansion control is executed. Control (hereinafter referred to as “accelerator-off guidance control”) is started. Hereinafter, the accelerator-off guidance control and the regeneration expansion control are collectively referred to as “prefetch deceleration control”.

  FIG. 2 is a diagram schematically illustrating an example of changes in the vehicle speed and the deceleration level when the pre-reading 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. In FIG. 2, an example of a change when the prefetch deceleration control is executed is indicated by a solid line, and an example of a change when the prefetch deceleration control is not executed is indicated by a one-dot chain line.

  FIG. 2 shows an example in which it is determined that there is a target stop position at a position D6 in front of the travel route. The target stop position is calculated based on 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-junction, and a temporary stop line.

  When the vehicle 1 reaches the predetermined position D1 before the travel path 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.

  When the vehicle 1 reaches the predetermined position D2 before the travel route from the calculated start position D4, the ECU 100 starts the accelerator-off guidance control described above. When the user who notices this guidance performs an accelerator-off operation, normal regeneration is started. Normal regeneration is regenerative control when regenerative expansion control is not being executed during inertial running with the accelerator off.

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

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

  When the pre-reading deceleration control is not executed (one-dot chain line), the accelerator-off guidance control is not executed. Therefore, the timing when the user performs the accelerator-off operation (position D3) is executed when the pre-reading deceleration control is executed (position D2). ). Further, normal regeneration is performed instead of regeneration expansion control even during inertial running after the accelerator-off operation. Therefore, the regenerative energy cannot be sufficiently recovered by the timing when the user performs the brake-on operation (position D5), and the regenerative energy is lost. On the other hand, in the present embodiment, by performing the above-described pre-reading deceleration control, the generation of regenerative energy is suppressed.

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

  Therefore, in the vehicle 1 configured to be able to selectively execute both, there may be a case where it is not possible to appropriately suppress the regenerative energy loss. 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, the free run control is not executed and the free run control is not executed. If the control is executed, there is a concern that the regenerative power generation amount cannot be increased although the vehicle 1 is predicted to stop or decelerate and the regenerative energy may be lost.

  Therefore, ECU 100 according to the present embodiment executes regenerative expansion control instead of free run control when there is a request for the other during execution of one of free run control and regenerative expansion control. Thereby, in the situation where the stop or deceleration of the vehicle 1 is predicted, the amount of regenerative power generation can be increased appropriately, and the 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-described free-run control, a look-ahead deceleration control unit 120, and an arbitration unit 130.

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

  Arbitration unit 130 is connected to free-run control unit 110 and regeneration expansion control unit 122, and performs arbitration when there is a request from the other during execution of one of free-run control and regeneration expansion control. Specifically, when the free-run control and the regeneration expansion control overlap, the arbitration unit 130 operates the regeneration expansion control with priority 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 regeneration expansion request (regeneration expansion control request) changes from off to on at the position D11 during free-run control. In this case, the arbitrating unit 130 stops the free run control and executes the regeneration expansion control.

  FIG. 5 is a diagram illustrating another example of the arbitration result obtained 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 D <b> 21 during regenerative expansion control. In this case, the arbitrating unit 130 does not execute the free run control but continues the execution of the regeneration 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 regeneration expansion request has changed from off to on.

  If the regeneration expansion request changes from OFF to ON (YES in S10), ECU 100 determines in S20 whether or not 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 regeneration expansion control in S22. If free-run control is not being performed (NO in S20), ECU 100 executes regenerative expansion control as it is in S22.

  If the regeneration 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 regeneration expansion control is being performed.

  If the regeneration expansion control is being performed (YES in S31), the ECU 100 rejects the free run request in S32 and does not execute the free run control, and continues to execute the regeneration expansion control in S22. If 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 regenerative expansion control instead of free run control when there is a request for the other during execution of one of free run control and regenerative expansion control. Thereby, in the situation where the stop or deceleration of the vehicle 1 is predicted, the amount of regenerative power generation can be increased appropriately, and the regenerative energy can be appropriately suppressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 vehicle, 2 accelerator pedal sensor, 3 brake pedal sensor, 4 shift sensor, 5 navigation device, 6 road-to-vehicle communication device, 7 HMI device, 10 engine, 20 1st MG, 30 2nd 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 guide control unit, 122 regeneration expansion control unit, 130 arbitration unit.

Claims (1)

A rotating electrical machine connected to the drive wheels of the vehicle;
A control device configured to selectively execute free-run control and regeneration expansion control,
The free run control is a control that reduces deceleration due to regeneration of the rotating electrical machine during inertial running of the vehicle, compared to when the free run control is not executed,
In the regeneration expansion control, when the vehicle is predicted to stop or decelerate during traveling, the deceleration due to regeneration of the rotating electrical machine during inertial traveling of the vehicle is not executed. Is more control than
The control device is configured to execute the regeneration expansion control without executing the free run control when there is a request for the other during execution of one of the free run control and the regeneration expansion control.

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