JPH11205913A - Output controller of motor for driving vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accelerator controllability at the time of climbing on a snow-covered slope. SOLUTION: A controller is provided with a snow switch operated by a driver. A motor load factor KA is so determined based on the degree of an accelerator opening VA that an accelerator characteristic may be such that while the snow switch is OFF, an accelerator imitates an engine and while the snow switch is ON, the linearity is strong and the appearance of the maximum value is suppressed. At the time of switching the snow switch from ON to OFF or vice versa, the motor load factor KA is changed from the one before switching to the one after switching in a plurality of control cycles, with a change following a change in the degree of the accelerator opening VA being allowed. The accelerator characteristics in an ON and an OFF state of the snow switch are provided, for example, on maps. The transition between the two states is made, for example, by mixing the two maps. The mixing ratio is determined with a speed characteristic taken into consideration and is guarded against going down below the minimum value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output control device for controlling an output of a motor used for propulsion of a vehicle such as an electric vehicle, that is, a vehicle propulsion motor, based on an output command determined according to a given command determination logic. About.

[0002]

2. Description of the Related Art In general, in an electric vehicle, a power conversion circuit such as an inverter or a chopper is provided on a power circuit from a vehicle-mounted power source such as a secondary battery or an engine driven generator to a vehicle propulsion motor. When propelling the vehicle, accelerator pedal operation, brake pedal operation,
An output command to the vehicle propulsion motor is determined according to a shift lever operation and the like, and the operation of this power conversion circuit is controlled based on the determined output command, so that the output of the vehicle propulsion motor can be requested by the vehicle operator. Control the output to be appropriate. When determining the output command, it follows a command determination logic for directly or indirectly associating information indicating the required output such as the accelerator opening with the value of the output command. This command determination logic is generally mounted on a circuit (for example, ECU: electronic control unit) that controls the operation of the above-described power conversion circuit in the form of a mathematical expression, a map, or the like.

[0003] Further, a control device for an electric vehicle which mounts a plurality of types of command determination logics and switches between them is also known. For example, in an apparatus described in Japanese Patent Application Laid-Open No. 4-299005, two types of modes, an economy mode and a power mode, are prepared. When a vehicle operator operates a mode changeover switch, the mode is changed from the economy mode to the power mode. Conversely, the correlation control characteristic of the field current of the vehicle propulsion motor versus the armature current switches. The switching of the correlation control characteristic here corresponds to a switching between a plurality of command determination logics.

[0004]

Here, as described in the above-mentioned publication, in the method of simply switching the command determination logic from one type to another type, a method of outputting an output command to a vehicle propulsion motor is disclosed. The value may change sharply. In order to solve this problem and realize smoother switching, it is necessary to set a transient period or a transition period of a certain length when switching the command determination logic, and to gradually increase or decrease the value of the output command within that period. What should I do? However, if the value of the output command during the transition period is managed in this way, even if the vehicle operator operates the pedal or lever for any reason, the operation is not immediately reflected in the output of the vehicle propulsion motor. Therefore, the drivability is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made in consideration of the above circumstances. When a request output given by a vehicle operator changes due to pedal operation, lever operation, or the like, a command determination logic is issued. It is an object of the present invention to provide a switching function of the command determination logic without deteriorating the drivability by allowing the change to be immediately reflected in the output of the vehicle propulsion motor even during the transition period related to the switching.

[0006]

SUMMARY OF THE INVENTION In order to achieve such an object, the present invention provides a method of directly outputting an output command value to a motor for propelling a vehicle in accordance with a required output and in accordance with a given command determination logic. In an output control device that determines the power output of the motor based on the output command,
A switching request detecting means for detecting a switching request related to the command decision logic, and a request output at that time at each of a plurality of times during a transition period at least until the switching of the command decision logic is completed after the switching request is detected. Means for sequentially determining the first output command value in accordance with the command determination logic of the switching source and the second output command value in accordance with the request output at that time and in accordance with the command determination logic of the switching destination; At least until the end of the transition period after the detection, based on the first and second output command values, unless the required output at the present time has a difference from the required output at the previous time, the output at the previous time Command change means for determining the current value of the output command for the motor so as not to show a significant change with respect to the command value. And butterflies.

In the present invention, when a switching request (for example, a switch operation by a vehicle operator) relating to a command determination logic (for example, a map or a mathematical formula) is detected, first and second output command values are determined and these first and second output command values are determined. And a process of determining a value of the output command to the motor based on the second output command value. This process is repeatedly executed at least until the switching of the command decision logic is completed, that is, until the output command value is determined exclusively by the command decision logic of the switching destination (during the transition period). Is done. Furthermore,
When determining the value of the output command to the motor based on the first and second output command values, the output command value is temporally changed so as not to show a significant change with respect to the output command value at the previous time. Impose limits on change. Therefore, in the present invention, a sudden change in the value of the output command due to the switching of the command determination logic is prevented and a smooth change is achieved. Further, in the present invention, the first and second output command values are determined for each time point according to the required output at each time point during the transition period.
Therefore, when a change occurs in the required output during the transition period (for example, when the vehicle operator depresses the accelerator pedal), the temporal change in the output command value is limited as described above. Therefore, a change accompanying a change in the required output appears in the value of the output command, and the drivability does not deteriorate. Note that the command determination logic may directly link the required output to the value of the output command,
They may be connected indirectly.

The command changing means in the present invention adds a predetermined value to the first output command value (or subtracts the predetermined value from the first output command value) at each time point during the transition period, and outputs the second output command value. It is good also as a structure which makes it gradually approach a command value. With this configuration, the rate of increase or decrease of the output command value during the transition period is constant regardless of the values of the first and second output command values. In order to secure a sufficiently long transition period and realize smoother switching regardless of the magnitude of the difference between the first output command value and the second output command value, the command removing / changing means must be provided with the first output command value. And a means for determining the value of the output command to the motor by weighted addition of the output command value and the second output command value. With this configuration, when the difference between the first output command value and the second output command value is small (other conditions are the same), the increase or decrease of the output command value for the motor becomes small, This results in smoother switching.

[0009] More preferably, the weight used by the command division unit for weighted addition is updated and determined at each point in time while limiting the temporal change amount. In this way, the first
Even if the difference between the output command value and the second output command value is large, the increase or decrease speed of the output command value for the motor can be suppressed, and the change in the value of the output command for the motor can be suppressed. Even more preferably, the weight used by the command division unit for weighted addition is updated and determined according to the vehicle speed and at each time point. In this way, for example, the first command decision logic in a low vehicle speed region and the second command decision logic in a high vehicle speed region can be switched together with the command decision logic according to the vehicle speed. Accordingly, it is possible to automatically depart from the previous command decision logic and shift to another command decision logic.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

(1) System Configuration FIG. 1 shows a schematic configuration of an electric vehicle according to an embodiment of the present invention. In the vehicle shown in FIG. 1, the discharge output of a vehicle-mounted battery 10 is converted from DC to three-phase AC by an inverter 12, and a three-phase AC motor 14 for driving the vehicle is driven by the three-phase AC power obtained from the inverter 12. Configuration. Since the rotor shaft of the motor 14 is directly connected to the drive wheels (not shown), that is, without using a connection opening / closing member such as a clutch or a torque converter, driving the motor 14 immediately generates a force for propelling the vehicle.

The power conversion operation of the inverter 12 is controlled by a control device 16 composed of an ECU or the like. The control device 16 constitutes an output control device related to the motor 14 together with the inverter 12. The control device 16 controls the accelerator opening degree V indicating the positions of an accelerator pedal, a brake pedal, and a shift lever (not shown).
A, A signal relating to the brake depression force and the shift position is input. The control device 16 determines a torque command Tref for the motor 14 using these signals as described later, and supplies a control signal generated based on the determined torque command Tref to the inverter 12 to control the power conversion operation. As a result, the motor 14 generates a torque corresponding to the torque command Tref, that is, an output torque corresponding to the pedal operation of the vehicle operator. The control device 16 further receives a signal indicating a rotor angular position from a rotation sensor 18 such as a resolver attached to the rotor of the motor 14, converts the signal into information indicating a vehicle speed such as the motor rotation speed N, and outputs a torque command. It is used when Tref is determined. This vehicle speed information
In the present embodiment, it is also used when determining a map mixture ratio Roff (described later).

FIG. 2 shows a torque command determination / output procedure which is repeatedly executed by the control device 16 at a predetermined cycle. In the procedure shown in this figure, the control device 16 first inputs signals generated at various parts of the vehicle such as the accelerator opening degree VA (10).
0), the motor load ratio is calculated and determined based on the input signal (104, 108), and the torque command Tref is determined based on the determined motor load ratio and motor rotation speed N (10).
6, 110), and generates a control signal based on the determined torque command Tref and gives it to the inverter 12 (112).

In executing this procedure, the control device 16 determines and determines whether to run the motor 14 or to perform regenerative braking based on the accelerator opening ratio VA and the brake depression force input in step 100. (102). Steps 104 and 106 described above are executed when it is determined that the vehicle is running, and steps 108 and 110 are executed when it is determined that the vehicle is regenerative braking.

In steps 104 and 108, a map for associating the accelerator opening ratio VA or the brake depression force with the motor load ratio is referred to by the accelerator opening ratio VA (in step 104) or the brake depression force (in step 108). By doing so, the motor load factor is determined. In the figure, KA is the motor load factor during power running, and KB is the motor load factor during regenerative braking. Steps 106 and 110
Then, the map 200 that associates the motor rotation speed N with the maximum torque Tmax and the minimum torque Tmin is referred to by the motor rotation speed N. In step 106, the torque command Tref is determined by multiplying the maximum torque Tmax obtained as a result of this reference by the motor load factor KA. In step 110, the minimum torque Tm obtained as a result of the reference is obtained.
The torque command Tref is determined by multiplying “in” by the motor load factor KB.

(2) Outline of Procedure for Determining Motor Load Factor KA A feature of the present embodiment is that the output control device related to the motor 14, particularly the control device 16, determines the motor load factor KA (1
04) There is a procedure to be executed. The snow switch 20 shown in FIG. 1 is a switch operated by the vehicle operator when climbing a snowy road or the like, and the KA in the present embodiment.
Related to the decision procedure.

First, since a motor has extremely low noise compared to an engine, it is generally difficult for an electric vehicle to perform a driving method of determining the driving state by operating the accelerator pedal and listening to the driving sound to operate the accelerator pedal. is there. On the other hand, as described above, in the vehicle according to the present embodiment, the rotor shaft of the motor 14 is directly connected to the drive wheels. Therefore, there is some difficulty in operating the accelerator when compared to a conventional engine vehicle. This difficulty is not apparent when traveling on flat roads or on roads under normal road conditions. However, this difficulty becomes apparent when trying to climb a snowy slope. That is, when the accelerator pedal is depressed on the snowy road and the motor and the driving wheels are rotated, the snow on the road is firmly pressed against the road surface by the first rotation, and thereafter the road surface is liable to slip. Once this road surface condition is reached, it becomes difficult to drive, especially climbing hills.

As one of measures against this phenomenon, the snow switch 2 is employed in the vehicle according to the present embodiment.
The idea is to switch the command determination logic during power running by operating 0. The command determination logic referred to here is, specifically, an accelerator opening ratio-motor load ratio map referred to by the accelerator opening ratio VA in step 104, or more generally, the vehicle operator operates the motor 14 The torque command Tre according to the output required for
Logic that is used in determining f directly or indirectly and defines the accelerator characteristic.

FIG. 3 shows an example of a command determination logic to be switched, that is, an accelerator opening ratio vs. motor load ratio map.
In FIG. 3, a solid line shows a map of the accelerator opening degree versus the motor load ratio which becomes dominant when the snow switch 20 is off, and a broken line shows that the snow switch 20 is It is an accelerator opening degree vs. motor load ratio map that becomes dominant when the switch is on. The characteristics defined by the solid-line map are preferably characteristics that emphasize response to an accelerator pedal operation, that is, acceleration feeling, such as characteristics simulating characteristics of an engine mounted on a conventional engine vehicle. On the other hand, the characteristics defined by the dashed map are characteristics suitable for climbing a snowy slope. More specifically, the linearity of the motor load ratio KA with respect to the accelerator opening degree VA is increased as compared with the map of the solid line, and the motor load ratio KA when the accelerator pedal is fully opened (when VA = 100%) is plotted on the map of the solid line. By lowering the value (δ in the figure, where 0 <δ <100), the vehicle operator can more suitably control the motor torque by operating the accelerator pedal.

In the present embodiment, some measures are taken for the procedure for switching the command decision logic during power running.

First, the accelerator opening ratio VA is the same between the case where it is determined with reference to the map shown by the solid line and the case where it is determined with reference to the map shown by the broken line in FIG. However, the motor load factor KA does not become the same. Therefore, assuming that the map, that is, the command determination logic is immediately switched in response to the operation of the snow switch 20, a sharp change occurs in the accelerator opening ratio KA and the torque command Tref as shown by a broken line in FIG. In order to suppress this change and realize smoother switching, in this embodiment,
As shown by the solid line in FIG.
The time change of f is limited.

However, during the transition period (see FIG. 4) after the operation of the snow switch 20 until the map switching is completed, it is assumed that the motor load factor KA is not allowed to change with time due to any cause. If so, inconvenience will occur. For example, when the vehicle operator depresses (or depresses) the accelerator pedal before the transition period ends after the snow switch 20 is operated, the depressing (or depressing) occurs before the transition period ends. If it does not appear as generation or change of the motor torque, drivability will eventually deteriorate. Therefore, in the present embodiment, as shown in FIG. 5, a change in the accelerator opening degree VA is immediately reflected in the motor load factor KA and, thus, the torque command Tref.

Further, if the switching between the accelerator opening ratio and the motor load ratio map is performed only in response to the operation of the snow switch 20, a problem may occur depending on the situation. For example, in the map shown in FIG. 3, the map when the snow switch is turned on indicated by the broken line gives a smaller motor load factor KA than the map when the snow switch is turned off indicated by the solid line. That is, in the state where the snow switch 20 is on, if the accelerator opening degree VA and the motor speed N are the same, only a small motor torque is generated as compared to the state where the snow switch 20 is off. Accordingly, if the vehicle operator forgets to turn off the snow switch 20 while keeping it on, there is a possibility that the power of the motor 14 will be insufficient. Therefore, in the present embodiment, control is performed such that the map when the snow switch is off automatically becomes dominant when the vehicle speed, specifically, the motor rotation speed N increases (software switch-off control). In other words, the snow switch 20 is used as a means for transmitting the map switching intention of the vehicle operator to the control device 16, and which of the current snow switch on map and the snow switch off map should be dominant. This is managed by software inside the control device 16. It should be noted that if the vehicle speed is high to some extent, it is possible to climb a snowy hill even if the drive wheels slightly slip (that is, even if the motor torque is controlled in accordance with the accelerator characteristic that emphasizes the acceleration feeling).

Further, switching of the accelerator opening ratio versus motor load ratio map, suppression of the temporal variation of the motor load ratio KA caused by this switching, permissible change of the motor load ratio KA due to change of the accelerator opening ratio VA, and Characteristic configuration such as software switch-off control for snow switch 20
In the present embodiment, the characteristic processing is realized by a method of mixing the map when the snow switch is on and the map when the snow switch is off, or based on this.

The term "mixing" as used herein means that the map when the snow switch is turned on (broken line in the example of FIG. 3) is used as the accelerator opening degree V
The process of determining the motor load factor KAon by referring to A and the process of determining the motor load factor KAoff by referring to the snow switch off map (solid line in the example of FIG. 3) by the accelerator opening degree VA. ,
That is, the two types of motor load factors KAon and KAoff obtained in parallel or before and after are combined by weighted addition to obtain the motor load factor KA.
If the weight 1-Roff multiplied by the motor load factor KAon at the time of weighted addition is sufficiently larger than the weight Roff multiplied by the motor load factor KAoff, the map at the time of the snow switch-on becomes dominant, and conversely, the weight 1-Roff becomes the weight Ro.
If the value is sufficiently smaller than ff, the map at the time of the snow switch off becomes dominant.
Is gradually started in response to the operation of the snow switch 20, whereby the actual switching of the accelerator opening ratio versus motor load ratio map and the motor load ratio K associated with this switching are performed.
The time variation of A is suppressed. In the following description, the weight Roff is referred to as a map mixture ratio.

Further, the two types of motor load factors KAon and KAoff to be subjected to "mixing", that is, the weighted addition, are each a map for associating the accelerator opening ratio VA and the motor load ratio with the current accelerator opening ratio VA. It is required by reference in. Therefore, the accelerator opening ratio VA
Changes in the motor load factors KAon and KAoff
, And as a result, a change generally appears in the motor load factor KA and, in turn, the torque command Tref. As described above, the motor load factors KAon and KAoff are determined in accordance with the accelerator opening ratio VA at that time for each of a plurality of control timings or control cycles arriving during the transition period. The appearing change in the accelerator opening degree VA can be reflected as a change in the motor load ratio KA.

Further, even if the snow switch 20 is not turned off when the motor rotation speed N, that is, the vehicle speed increases, the accelerator opening degree-motor load ratio map for snow switch off automatically becomes dominant. The software-based switch-off control for controlling the map mixing ratio Rof
This is realized by giving f a characteristic with respect to the motor rotation speed N. More specifically, a motor rotation speed versus map mixing ratio map whose contents are set so that the map mixing ratio Roff decreases when the motor rotation speed N is low and increases when the motor rotation speed N is high is expressed by the motor rotation speed at each time. N
, And determines the map mixture ratio Roff, thereby realizing software-based switch-off control. In this control, a change by the minimum value guard Rmin is imposed on the change of the map mixture ratio Roff, so that the change of the motor load ratio KA is further smoothed.

(3) Flow of Motor Load Factor KA Determination Procedure FIG. 6 shows a routine called at step 104 in FIG. 2 to determine the motor load factor KA in the operation of the control device 16 in this embodiment. Show the flow. In the routine shown in this figure, the control device 16 first calculates and determines the minimum guard Rmin (300), and then calculates and determines the map mixture ratio Roff (302). The control device 16
If the shift position is in the D or B range, (3
04), using the map 400A, the motor load factor KAo
n (306), the motor load factor KAoff is determined using the map 400B (308), and if not (304), the motor load factor KAon is determined using the map 400C (310). The motor load factor KAoff is determined (312) using 400D, respectively. The control device 16 determines the motor load factors KAon and K
Aoff is calculated by the following weighted addition

KA = Roff · KAoff + (1−Roff
f) Mix by KAon to determine the motor load factor KA (314).

The four types of maps 400A to 400D used in the procedure of FIG. 6 are all types of the accelerator opening degree-motor load ratio map described above. Each map shows the accelerator opening ratio VA and motor load ratio (KAon or KAo).
ff) for a plurality of points, and in steps 306 to 312, the current accelerator opening degree VA
The motor load factor (KAon or KAoff) is obtained by (linear) interpolation from at least two points close to. The map 400A is a snow switch-on map corresponding to the broken line in FIG. 3, and the map 400B is a snow switch-off map corresponding to the solid line. The maps 400C and 400D are also maps for when the snow switch is on or when the snow switch is off. However, the maps have higher linearity than the map 400B so as to be used only when the shift position is not D, B, or the like.

Further, at step 300, the routine shown in FIG. 7 is called to determine the minimum guard Rmin. In this routine, the control device 16 determines whether the snow switch 20 is on or off (500). If the snow switch 20 is on, the controller 16 reduces the minimum value guard Rmin (502). The processing for increasing the size (504) is executed. Specifically, the following equation

Rmin ← Rmin−KDKAon: When the snow switch is ON (502) Rmin ← Rmin + KDKAoff: When the snow switch is OFF (504) However, KDKAon, KDKoff: A process indicated by a small positive value (gradual change amount) is executed. Since the procedure shown in FIG. 7 is repeatedly executed periodically, when the snow switch 20 is on, the minimum value guard Rmin is gradually reduced by repeatedly executing step 502, and conversely, the snow switch 20 is turned off. If there is, the minimum value guard Rmin is gradually increased by repeatedly executing step 504. When the minimum value guard Rmin falls below 0 as a result of the gradual decrease (506), the control device 16 sets the minimum value guard Rmin to 0 (508), and as a result of the gradual increase, the minimum value guard Rmin becomes 100.
(510), the minimum guard Rmin is set to 100 (512).

Before determining whether the snow switch 20 is on or off, the control device 16 determines whether the shift position belongs to a range, such as P or N, where the vehicle is not intended to travel (514). ) And accelerator opening ratio V
It is determined whether or not A has become 0 over the predetermined time T1 (516). If any one of the conditions is satisfied, the map mixture ratio Rof based on the minimum value guard Rmin.
Even if the restriction on f is released, it can be considered that trouble such as a sudden change in torque cannot occur. Therefore, when either of the conditions in steps 514 and 516 is satisfied, the control device 16 sets the minimum guard Rmin to 0 (520) if the snow switch 20 is on (518), and turns off the snow guard 20 if the snow switch 20 is on (518). Ba (51
8) By setting it to 100 (522), the restriction on the map mixture ratio Roff by the minimum value guard Rmin is substantially released.

In the routine called at step 302 to determine the map mixture ratio Roff, FIG.
As shown in (1), the map 700 is referred to by the absolute value of the motor rotation speed N, that is, the absolute value of the vehicle speed (600). The map 700 is a map that associates the absolute value of the motor rotation speed N to the absolute value of the vehicle speed with the map mixture ratio Roff. As shown in the drawing, Roff = 0 (%) in the low speed region, Roff = 100 (%) in the high speed region, 0 in the middle speed range
A speed characteristic that gradually transitions from (%) to 100 (%) is given to the map mixture ratio Roff. Control device 16
Uses the map mixture ratio Roff obtained by referring to the map 700 in step 314 described above.
However, in order to suppress a change in the map mixture ratio Roff, if the map mixture ratio Roff is smaller than the minimum guard Rmin (602), the minimum guard Rmin is set as the map mixture ratio Roff (604), and step 314 is executed.

(4) Other Embodiments In the embodiments described above, the present invention is implemented by means of "mixing" of maps, but the present invention can be implemented by other means. For example, the output control device according to the present invention can be configured such that the control state transitions according to the procedure shown in FIG.

In FIG. 9, the reference numeral 800A denotes a normal control state in which the map of the accelerator opening degree to the motor load ratio is used when the snow switch is off, and the reference numeral 800C denotes a snow switch. This is a snow mode state in which the accelerator opening degree versus motor load ratio map for the ON state is dominant. Also, the normal control state 8 is indicated by 800B.
The transition from 00A to the snow mode state 800C is a characteristic change start state in which control for smoothly changing the motor load factor KA is performed. The state indicated by 800D is a transition from the snow mode state 800C to the normal control state 800A. This is a characteristic change end state in which the control for smoothly changing the motor load ratio KA is performed when performing the operation.

In the normal control state 800A, a value KAoff determined by a map of an accelerator opening degree to a motor load ratio (for example, a solid line in FIG. 3) for when the snow switch is off is:
It is used as a motor load factor KA for determining the torque command Tref. In addition, the characteristic change start state 800B
Variable D used in the status change and characteristic change end state 800D
KA has been reset to zero.

When the condition for starting the transition to the snow mode state 800C is satisfied (in the system of FIG. 1, the snow switch 20 is operated by the vehicle operator and the vehicle speed (or motor speed N) at that time). (When the absolute value is equal to or less than the predetermined value v1),

DKA = DKA + KDKAon KA = max (KAoff−DKA, KAon) where, max (·): the process shown in the function for obtaining the maximum value, that is, the motor load factor KA is calculated by the following equation. The process of decreasing the KDKon by KAoff-DKA <KAon
State continues for a predetermined time T2 or more or the characteristic change start state 80
0B is a predetermined time T3 (however, T3 is sufficiently longer than T2)
It is repeatedly executed until one of the following is reached. It should be noted that the motor load factors KAon and KAoff are sequentially determined based on the accelerator opening degree VA at each time point, that is, FIG.
Note that this provides a responsiveness to accelerator operation as shown in FIG. In the subsequent snow mode state 800C, the value KAon determined by the accelerator opening ratio versus motor load ratio map (for example, the broken line in FIG. 3) for the time when the snow switch is turned on is the torque command T
It is used as a motor load factor KA for determining ref. The variable for integration DKA has been reset to zero.

When the condition for terminating the snow mode state 800C is satisfied (in the system shown in FIG. 1, the snow switch 20 is operated by the vehicle operator and the absolute value of the vehicle speed (or motor speed N) at that time) Is the predetermined value v2
Is greater than or equal to)

DKA = DKA + KDKAoff KA = min (KAon + DKA, KAoff) where min (·): the function indicated by the function for obtaining the minimum value, that is, the motor load factor KA (excluding the change due to the change in the accelerator opening ratio VA) B) The process of increasing KDKAoff by KAon + DKA> KAoff
The state of f continues for a predetermined time T4 or more, or the characteristic change end state 8
It is repeatedly executed until 00D continues for a predetermined time T5 (T5 is sufficiently longer than T4) or any time.

According to such a procedure, the functions and effects obtained in the above-described embodiment, that is, the improvement of the accelerator controllability at the time of climbing a snowy hill, the smooth switching of the command determination logic, and the accelerator operation can be achieved. Responsiveness, software switch-off control, etc. can be realized.

(5) Supplement In the above embodiment, the map is used as the command decision logic. However, a mathematical expression can be used as the command decision logic. Further, the motor load factor K is calculated from the accelerator opening degree VA.
A, and the procedure of determining the torque command Tref from the motor load factor KA and the motor speed N is used. However, when the present invention is implemented, the accelerator opening ratio VA, the motor speed N May be used to determine the torque command Tref from. In that case, "command decision logic"
Corresponds to, for example, a three-dimensional map that associates the accelerator opening degree VA, the motor rotation speed N, and the torque command Tref. Also, while weighted addition has been described as a technique for realizing "mixing" of maps, a technique other than simple weighted addition can be used for "mixing".

The application of the present invention is not limited to the vehicle shown in FIG. For example, the present invention can be applied to a vehicle that uses a DC motor instead of an AC motor for vehicle propulsion, a vehicle that uses a chopper instead of an inverter, and the like. Furthermore, the application of the present invention is not limited to a so-called pure electric vehicle. For example, a parallel hybrid vehicle having a power source such as an engine connected in parallel with a motor as viewed from the drive wheel side, an engine drive generator that can be used as a means for supplying drive power to a motor and charging a battery, and the like. The present invention can be applied to a series hybrid vehicle having a power source, or a vehicle having a configuration in which a parallel hybrid vehicle and a series hybrid vehicle are combined.

In addition, the application of the present invention is not limited to climbing a snowy slope. That is, the present invention can be applied to any vehicle that adopts a control method in which switching / transition is performed between a plurality of command determination logics mounted on the vehicle. For example, in a parallel hybrid vehicle in which an engine and a motor are connected in parallel when viewed from the driving wheel side, a case in which the command determination logic related to the motor is switched in order to switch the operating state on the motor side according to the operating state on the engine side. The present invention can be applied to any of them. Further, in a four-wheel drive vehicle that supplies torque to each drive wheel from a common motor, the mode is switched between a mode in which all four drive wheels are driven and a mode in which only two of the drive wheels are driven. The present invention can be applied to a case where the command determination logic is switched.

[0042]

As described above, according to the present invention,
When a switching request for the command decision logic is detected, the first
And a second output command value, and the first and second output command values are limited while imposing a limit on the temporal change of the output command value so as not to show a significant change with respect to the output command value at the previous time. The process of determining the value of the output command to the motor based on the output command value is repeatedly executed at least during the transition period until the switching of the command determination logic is completed. A sudden change in the output command value can be prevented and a smooth change can be made. Furthermore, since the first and second output command values are determined at each time point according to the required output at each time point during the transition period, when the required output changes during the transition period, the above-described restriction is imposed. Nevertheless, a change associated with a change in the required output will appear in the value of the output command, and deterioration of drivability can be prevented.

Further, if the first output command value and the second output command value are weighted and added to determine an output command value for the motor, the first output command value and the second output command value are determined. Is small, the increase or decrease of the output command value for the motor per unit time is small, so that a smoother change in the motor output can be realized. Further, if the weight used in the weighted addition is determined to be updated at each time while limiting the temporal change amount, the difference between the first output command value and the second output command value is large. However, the increase or decrease speed of the output command value to the motor can be suppressed, and the change of the output command value to the motor can be suppressed. Furthermore, if the weight used for the weighted addition is updated and determined at each time according to the vehicle speed, for example, the first command determination logic is used in a low vehicle speed region, and the second command determination logic is used in a high vehicle speed region. Switching of the command decision logic according to the vehicle speed can be realized at the same time, and it is also possible to automatically shift from the previous command decision logic to another command decision logic according to a change in the vehicle speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of an electric vehicle suitable for carrying out the present invention.

FIG. 2 is a flowchart illustrating a schematic operation of a control device.

FIG. 3 is a diagram showing an example of an accelerator opening degree versus motor load ratio map.

FIG. 4 is a timing chart for explaining processing at the time of switching of command determination logic.

FIG. 5 is a timing chart for explaining processing at the time of switching of command determination logic.

FIG. 6 is a flowchart illustrating a routine for determining a motor load factor during power running.

FIG. 7 is a flowchart illustrating a routine for determining a minimum value guard.

FIG. 8 is a flowchart illustrating a routine for determining a map mixture ratio.

FIG. 9 is a control state transition diagram showing a control procedure in another embodiment.

[Explanation of symbols]

10 battery, 12 inverter, 14 motor, 1
6 Control device, 20 snow switches, VA accelerator opening ratio, KA, KAon, KAoff Motor load ratio, R
min Minimum value guard, Roff map mixture ratio, T
ref Torque command.

Claims (4)

[Claims] An output command value for a motor for propelling a vehicle is directly or indirectly determined according to a required output and according to a given command determination logic, and the output of the motor is determined based on the output command. An output control device for controlling, wherein: a means for detecting a switching request related to the command decision logic; and a plurality of times during a transition period at least until the switching of the command decision logic is completed after the detection of the switching request. Means for sequentially determining a first output command value according to the request output at the time and according to the command determination logic of the switching source, and a second output command value according to the request output at the time and according to the command determination logic of the switching destination At least until the end of the transition period after the detection of the switching request, based on the first and second output command values and at a previous time. Unless the required output at the present time has a difference with respect to the required output, the command removal for determining the current value of the output command to the motor so that the output command value at the previous time does not significantly change. And an output control device. 2. The output control device according to claim 1, wherein
The command change means includes a first output command value and a second output command value.
An output control device comprising means for weighting and adding the output command value of the motor to determine the value of the output command for the motor. 3. The output control device according to claim 2, wherein
An output control device, wherein the command changing means includes means for updating and determining the weight used in the weighted addition at each time while limiting a temporal change amount thereof. 4. The output control device according to claim 2, wherein said command changing means includes means for updating and determining a weight used in said weighted addition in accordance with a vehicle speed and at each time point. Output control device.