JP2004129459A - Speed command control unit and speed controller for electrically-propelled vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly suppress the phenomenon of pitching and ensure stable running when pitching running occurs in an electrically-propelled vehicle, such as forklift. <P>SOLUTION: An accelerator input processing portion 101 generates a speed command ω* corresponding to the amount of accelerator 10 pedal depression. A pitching detecting portion 104 samples the detected speed ω in each sampling period. If the difference between maximum detected speed and minimum detected speed is greater than a pitching detection level, the pitching detecting portion determines that the phenomenon of pitching has occurred. A speed command adjusting portion 105 operates as follows: when the occurrence of the phenomenon of pitching is not determined, the speed command adjusting portion externally outputs the speed command ω* generated by the accelerator input processing portion 101. When the occurrence of the phenomenon of pitching is determined, the speed command adjusting portion externally outputs a speed command ω* obtained by halving the sum of the maximum detected speed and the minimum detected speed. The speed of an induction motor 30 is controlled according to the value of the speed command ω*. Therefore, if pitching takes place, the value of the speed command ω* is reduced, and the phenomenon of pitching is suppressed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a speed command control unit and a speed control device for an electric vehicle, and is devised so that a pitching phenomenon can be quickly and reliably suppressed even if the electric vehicle is pitched when the electric vehicle is loaded. It was done. Note that the load traveling refers to traveling with the electric vehicle loaded with luggage and the like.
[0002]
[Prior art]
In an electric vehicle such as an electric forklift or an electric vehicle, a DC voltage of a battery is converted into an AC voltage by an inverter to drive an AC motor, and the AC motor is used as a drive source to obtain a driving force during traveling. Induction motors are frequently used in this type of drive motor, and a vector control method is employed as a speed control method for the induction motor (see, for example, Patent Document 1). FIG. 7 is a block diagram illustrating a speed control device for an electric vehicle using a vector control method according to the related art.
[0003]
As shown in FIG. 7, this speed control device mainly includes a speed command control unit 100, a vector control unit 200, and a motor drive command control unit 300.
[0004]
The control operation of this speed control device is outlined as follows. That is, the speed command control unit 100 sets the speed command ω (proportional) according to the amount of depression of the accelerator 10.^*Is output. The vector control unit 200 converts the actual speed (detected speed) ω of the electric vehicle into a speed command ω^*To obtain the two-phase torque current command I_q ^*And the exciting current command I_1d ^*Is output. The motor drive command control unit 300 outputs the current command I_q ^*, I_1d ^*-Phase voltage command (motor drive command) V according to_u ^*, V_v ^*, V_w ^*Is output.
[0005]
The inverter 20 has a voltage command (motor drive command) V_u ^*, V_v ^*, V_w ^*, The DC current of the battery B is converted into a three-phase AC current and supplied to the induction motor 30. Thus, the induction motor 30 is driven to drive the electric vehicle. As a result, the speed of the electric vehicle can be controlled according to the amount of depression of the accelerator 10.
[0006]
The rotation speed of the induction motor 30 is detected by a rotation speed sensor (pulse pickup) 40, and a pulse signal P indicating the rotation speed is output from the rotation speed sensor 40, based on the pulse signal P. The detection speed ω is obtained.
[0007]
Next, a detailed configuration and operation of each control unit 100, 200, 300 of the above-described speed control device will be described.
[0008]
The speed command control unit 100 includes an accelerator input processing unit 101, a cushion processing unit 102, and a torque current command limit processing unit 103.
[0009]
The accelerator input processor 101 includes an accelerator voltage V corresponding to the amount of depression of the accelerator 10._inIs entered. Then, the accelerator input processing unit 101 outputs the accelerator voltage V_inSpeed command ω according to^*Is output.
The cushion processing unit 102 sets the speed command ω after a certain time delay after the accelerator 10 is depressed.^*Is output.
The torque current command limit processing unit 103 generates a torque current command limit value I according to the detected speed ω._q-Lim is output. This torque current command limit value I_qThe maximum value of −lim is I_q0It has become. Note that ω_bIs the basal velocity.
[0010]
The vector control unit 200 includes a PI (proportional-integral) calculation unit 201, a magnetic flux command unit 202, a slip calculation unit 203, a speed calculation unit 204, and the like.
[0011]
The PI calculation unit 201 calculates the speed command ω^*Speed Δω, which is the difference between the speed and the detected speed ω, and the speed PI gain K_p,K_iBased on the torque current command I_q ^*Ask for. However, the torque current command I_q ^*Is the torque current command limit value I_q-Lim is limited to the upper limit. Also, the speed PI gain K_p,K_iMeans that the detected speed ω is the base speed ω_bIs exceeded, it is multiplied by a predetermined number by the multipliers 205 and 206 as described later.
[0012]
The magnetic flux command unit 202 outputs a magnetic flux command λ corresponding to the detected speed ω.^*Is output. This magnetic flux command λ^*Is λ_oIt has become. Note that ω_bIs the basal velocity.
[0013]
Magnetic flux command λ^*Is the excitation current command I_1d ^*Is multiplied by the gain G in order to increase the responsiveness. Then, through an M (mutual inductance) fluctuation compensation table 207 and a divider 208, the excitation current command I_1d ^*Is obtained.
Also, the magnetic flux command λ^*Is the magnetic flux command λ via the primary delay unit 209₁ ^*Becomes Note that τ₂Is the second order time constant.
[0014]
The multiplication gain calculator 210 calculates the fixed value Id_o(= Mλ_o) With Id (= Mλ₁ ^*) To obtain a multiplication gain. The multiplication gain is calculated by the multipliers 205 and 206 for the speed PI gain K._p,K_iIs multiplied by Note that the multiplication gain is such that the detected speed ω is the base speed ω_bSmaller than λ₁ ^*= Λ_oAnd the detection speed ω becomes the base speed ω_bIs greater than₁ ^*<Λ_oTherefore, it is larger than 1.
[0015]
The slip calculation unit 203 calculates the excitation current command I_1d ^*Magnetic flux command λ corresponding to₁ ^*And the torque current command I_q ^*From the sliding speed ω_sAsk for. The speed calculation unit 204 calculates the detected speed ω from the pulse signal P. And the sliding speed ω_sAnd the detected velocity ω, the primary angular velocity ω_oIs obtained.
[0016]
The motor drive command control unit 300 includes a current control unit 301, coordinate conversion units 302 and 303, an integrator 304, a speed estimation unit 305, and the like.
[0017]
The current control unit 301 controls the excitation current command I_1d ^*And torque current command I_q ^*Gain K_idAnd gain K_lqAnd the exciting current detection value I_1dAnd torque current detection value I_1qAnd the primary angular velocity ω_o, The two-phase excitation voltage command V_d ^*And torque voltage command V_q ^*Ask for. Two-phase excitation voltage command V_d ^*And torque voltage command V_q ^*Is a three-phase voltage command (motor drive command) V_u ^*, V_v ^*, V_w ^*Becomes
The excitation current detection value I_1dAnd torque current detection value I_1qIs the detected three-phase current I_u,I_wIs converted by the coordinate converter 302.
[0018]
The integrator 304 calculates the primary angular velocity ω_o, The phase angle θ (the angle between the d-axis and the rotor) required for the coordinate transformation is obtained.
[0019]
The speed estimating unit 305 calculates the excitation voltage command V_d ^*, Torque voltage command V_q ^*, Detected three-phase current I_u,I_w, The rotational speed of the induction motor 30 is estimated. When the rotation speed sensor 40 is not used, the estimated speed estimated by the speed estimation unit 305 is used instead of the detected speed ω.
[0020]
In the example of the above description, an induction motor is used as a drive motor of an electric vehicle, and speed control is performed by a vector control method.However, a synchronous motor is used as a drive motor of an electric vehicle, and speed control is performed by a vector control method. There is also a type that uses a DC motor as a drive motor for an electric vehicle and controls the speed by adjusting a current conduction ratio (duty) supplied to the DC motor.
[0021]
[Patent Document 1]
JP 2000-308399 A
[0022]
[Problems to be solved by the invention]
In the speed control device shown in FIG. 7, when the depression amount (operation amount) of the accelerator 10 is the maximum, the speed command ω^*Is also maximum, and the detected speed ω of the induction motor 30 is equal to the command speed command ω.^*, The torque current command I is calculated by PI calculation._q ^*Is calculated.
[0023]
The speed command ω is obtained when the stepping amount (operating amount) of the accelerator 10 is maximum.^*When the electric vehicle is run under no load at the time when the maximum is also reached, or when the stepping amount (operating amount) of the accelerator 10 is reduced, the speed command ω^*When the vehicle is driven at a low speed, the motor torque characteristic of the induction motor 30 has a sufficient margin with respect to the traveling load torque.^*And the detected speed (actual speed) ω substantially coincides, and the vehicle travels.
[0024]
However, when the stepping amount (operating amount) of the accelerator 10 is maximum, the speed command ω^*When the electric vehicle is run under load at the time when the maximum is also reached, the vehicle travels at a point where the motor torque characteristic of the induction motor 30 is balanced with the traveling load torque characteristic, and the detected speed (actual speed) ω is the speed. Command ω^*The vehicle travels in a state where the vehicle is lower than the vehicle.
[0025]
When the running load torque fluctuates during running of the electric vehicle (for example, when the running road surface changes from a flat road surface to a bad road surface), resonance occurs due to the natural vibration of the electric vehicle and the electric vehicle runs pitching. Sometimes. When the vehicle is pitched as described above, the front side of the electric vehicle sinks and the rear side floats, and the center of gravity of the vehicle swings forward. (Actual speed) ω also vibrates (the speed moves up and down over time).
[0026]
Speed command ω^*And the detected speed (actual speed) ω substantially coincides with each other, and when the vehicle is traveling (when the traveling load torque is within the range of the motor torque characteristic or when the vehicle is traveling with no load), the vehicle enters the pitching traveling state. The speed command ω^*And the detected torque ω to make the torque current command I_q ^*, The pitching traveling phenomenon is suppressed.
[0027]
However, the speed command ω^*And the detected speed (actual speed) ω coincides and the vehicle is not traveling (the traveling load torque exceeds the motor torque characteristic and sticks to the motor torque characteristic, and the detected speed ω becomes the speed command ω^*(When the vehicle is traveling at a lower level than when the vehicle is running), when the vehicle enters the pitching traveling state, the torque current command I by the speed PI calculation is obtained._q ^*Is limited by the motor torque characteristic (that is, the torque current command I_q ^*Is the maximum), the torque current command I_q ^*Does not change. For this reason, the pitching traveling phenomenon is not suppressed, and the electric vehicle travels in a vibrating state. When the vehicle travels in the vibrating state, the driver feels fear.
[0028]
In view of the above prior art, the present invention provides a speed command control unit and a speed command control unit that quickly suppresses this pitching phenomenon and enables stable running even when pitching running occurs when the electric vehicle is loaded. It is an object to provide a speed control device.
[0029]
[Means for Solving the Problems]
A configuration of a speed command control unit of the present invention that solves the above-mentioned problem is incorporated in a speed control device of an electric vehicle that uses an electric motor as a drive source, and outputs a speed command according to an accelerator pedal depression amount. At
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
Based on a detection speed that is an actual rotation speed of the electric motor, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit A speed command adjusting unit that obtains a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed at the time of pitching and outputs the speed command to the outside, in place of the speed command generated in It is characterized.
[0030]
The configuration of the speed command control unit of the present invention is incorporated in a speed control device of an electric vehicle using an electric motor as a drive source, and in a speed command control unit that outputs a speed command according to an accelerator pedal depression amount,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit A speed command adjusting unit that obtains a speed command that is half the sum of the maximum detected speed and the minimum detected speed in the sampling period in which pitching has occurred, and outputs the speed command to the outside instead of the speed command generated in And characterized in that:
[0031]
The configuration of the speed command control unit of the present invention is incorporated in a speed control device of an electric vehicle using an electric motor as a drive source, and in a speed command control unit that outputs a speed command according to an accelerator pedal depression amount,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit In place of the speed command generated in the above, a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed in the sampling period in which the occurrence of pitching is detected is obtained and output to the outside. And a speed command adjusting unit that holds the value of the speed command to be output at half the sum of the maximum detection speed and the minimum detection speed over a predetermined hold period.
[0032]
The configuration of the speed command control unit of the present invention is incorporated in a speed control device of an electric vehicle using an electric motor as a drive source, and in a speed command control unit that outputs a speed command according to an accelerator pedal depression amount,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit In place of the speed command generated in the above, a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed in the sampling period in which the occurrence of pitching is detected is obtained and output to the outside. Having a speed command adjusting unit that raises the value of the speed command after holding the value of the speed command to be output at half the value of the sum of the maximum detection speed and the minimum detection speed over a predetermined hold period, I do.
[0033]
The configuration of the speed command control unit of the present invention is incorporated in a speed control device of an electric vehicle using an electric motor as a drive source, and in a speed command control unit that outputs a speed command according to an accelerator pedal depression amount,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit In place of the speed command generated in the above, a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed in the sampling period in which the occurrence of pitching is detected is obtained and output to the outside. After holding the value of the speed command to be half of the sum of the maximum detection speed and the minimum detection speed over a predetermined hold period, the speed command value is increased, and the rate of increase is changed from when the electric vehicle is stopped. A speed command adjusting unit that makes the rate of increase smaller than the rate of acceleration when accelerating.
[0034]
Further, the speed control device for an electric vehicle according to the present invention includes the above speed command control unit,
A torque current command according to the speed command output from the speed command control unit, and a vector control device that outputs an excitation current command,
A motor drive command control unit that sends a three-phase voltage command corresponding to the torque current command and the excitation current command to an inverter that supplies an AC current to an AC motor that is a drive source.
In this case, the AC motor employs an induction motor or a synchronous motor.
[0035]
Further, the speed control device for an electric vehicle according to the present invention includes the above speed command control unit,
A motor drive command control unit that outputs a duty command according to the speed command output from the speed command control unit,
A current control unit that supplies a DC current corresponding to the duty command to a DC motor as a driving source.
[0036]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. Note that the same reference numerals are given to portions that perform the same functions as those in the related art, and description of overlapping portions will be simplified.
[0037]
FIG. 1 is a block diagram showing a speed control device for an electric vehicle using a vector control method according to the present invention.
[0038]
As shown in FIG. 1, this speed control device mainly includes a speed command control unit 100A, a vector control unit 200, and a motor drive command control unit 300.
[0039]
The vector control unit 200, the motor drive command control unit 300, the accelerator 10, the inverter 20, the induction motor 30, the rotation speed sensor 40, and the battery B have the same functions as those of the related art shown in FIG.
[0040]
That is, the vector control unit 200 sets the actual speed (detected speed) ω of the electric vehicle to the speed command ω.^*To obtain the two-phase torque current command I_q ^*And the exciting current command I_1d ^*Is output. The motor drive command control unit 300 outputs the current command I_q ^*, I_1d ^*-Phase voltage command (motor drive command) V according to_u ^*, V_v ^*, V_w ^*Is output.
[0041]
The inverter 20 outputs a voltage command (motor drive command) V_u ^*, V_v ^*, V_w ^*, The DC current of the battery B is converted into a three-phase AC current and supplied to the induction motor 30. Thus, the induction motor 30 is driven to drive the electric vehicle. The rotation speed of the induction motor 30 is detected by a rotation speed sensor (pulse pickup) 40, and a pulse signal P indicating the rotation speed is output from the rotation speed sensor 40, based on the pulse signal P. The detection speed ω is obtained.
[0042]
The speed command control unit 100A includes a pitching detection unit 104 and a speed command adjustment unit 105 in addition to the accelerator input processing unit 101, the cushion processing unit 102, and the torque current command limit processing unit 103.
[0043]
Among them, the accelerator input processing unit 101, the cushion processing unit 102, and the torque current command limit processing unit 103 have the same functions as those of the related art shown in FIG.
[0044]
That is, the accelerator input processor 101 includes an accelerator voltage V corresponding to the amount of depression of the accelerator 10._inIs entered. Then, the accelerator input processing unit 101 outputs the accelerator voltage V_inSpeed command ω according to^*Is output.
The cushion processing unit 102 sets the speed command ω after a certain time delay after the accelerator 10 is depressed.^*Is output.
The torque current command limit processing unit 103 generates a torque current command limit value I according to the detected speed ω._q-Lim is output. This torque current command limit value I_qThe maximum value of −lim is I_q0It has become. Note that ω_bIs the basal velocity.
[0045]
The pitching detection unit 104 outputs the speed command ω output from the accelerator input processing unit 101 and passing through the cushion processing unit 102.^*Then, the occurrence of pitching is detected by performing the processing shown in the flowchart of FIG. 2 based on the detected speed (actual speed) ω.
[0046]
First, the speed command ω output from the accelerator input processing unit 101^*, And the detection speed ω is equal to or higher than the set speed (for example, 10 km / h), and the pitching detection operation is started (step 1).
[0047]
The pitching detection operation is continuously performed every predetermined sampling period (for example, every second). That is, the pitching detection operation is performed in the preceding sampling period (for example, one second), and the pitching detection operation is also performed in the succeeding sampling period (for example, one second) immediately after this sampling period. In this pitching detection operation, first, the detection speed ω is continuously sampled in each sampling period of one second, and the maximum detection speed ω during the sampling period is sampled._maxAnd minimum detection speed ω_minIs extracted (step 2). And the maximum detection speed ω_maxAnd minimum detection speed ω_minIs larger than a predetermined pitching detection level (step 3), it is determined that pitching has occurred (step 4).
[0048]
When it is determined that pitching has occurred, the pitching detection signal α is output to the speed command adjusting unit 105. At the same time, the maximum detection speed ω of the detection speed ω during this sampling period_maxAnd minimum detection speed ω_minIs output to the speed command adjusting unit 105. Note that the detected speed ω is input to the speed command adjusting unit 105, and the maximum detected speed ω during the sampling period in which pitching has occurred._maxAnd minimum detection speed ω_minMay be detected by the speed command adjusting unit 105.
[0049]
In the pitching detection unit 104, the speed command ω output from the accelerator input processing unit 101^*, And the detected speed ω is equal to or higher than a set speed (for example, 10 km / h). In order to start the pitching detection operation, the maximum detection is performed during the period when the electric vehicle accelerates from the stop state to the set speed. Speed ω_maxAnd minimum detection speed ω_minIs larger than the predetermined pitching detection level, it is not determined that pitching has occurred. Below this set speed, even if the speed of the electric vehicle fluctuates (the speed fluctuates up and down over time), there is no problem, so such a determination method is adopted. As a result, when the electric vehicle is traveling at or below the set speed, it is not erroneously determined that pitching has occurred.
[0050]
The sampling period is, for example, one second. This period is determined from the vibration frequency when various electric vehicles are pitched. In this sampling period, on the condition that there are at least two peaks of the speed (portion that decreases after the speed increases) and at least two valleys of the speed (portion that increases after the speed drops). It has been decided.
[0051]
When the pitching detection signal α is not input, the speed command adjusting unit 105 outputs the speed command ω output from the accelerator output processing unit 101.^*Is transmitted as it is to the vector control unit 200.
[0052]
On the other hand, when the pitching detection signal α is input, the speed command adjusting unit 105 outputs the speed command ω output from the accelerator output processing unit 101.^*Is passed as it is, and instead, the speed command ω is a value obtained by performing the processing shown in the flowchart of FIG.^*To the vector control unit 200.
[0053]
Here, the operation when the pitching detection unit 104 detects the occurrence of pitching and the pitching detection signal α is input to the speed command adjusting unit 105 will be described with reference to FIG.
[0054]
As shown in FIG. 3, when the occurrence of pitching is detected (step 11), the speed command ω^*Of the maximum detection speed ω_max+ Minimum detection speed ω_min) / 2 (step 12). Maximum detection speed ω_maxAnd minimum detection speed ω_minIs the speed sent from the pitching detection unit 104 to the speed command adjustment unit 105 or detected by the speed command adjustment unit 105 itself. In this way, the value is expressed as (the maximum detection speed ω_max+ Minimum detection speed ω_min) / 2 speed command ω^*To the vector control unit 200.
[0055]
And the speed command ω^*Value (maximum detection speed ω_max+ Minimum detection speed ω_min) / 2 is held for a holding period T set in advance. When the hold period T elapses, the speed command ω^*Is set to a value corresponding to the amount of depression of the accelerator 10 (ie, the speed command ω output from the accelerator input processing unit 101).^*(Step 13). At this time, after the hold period T has elapsed, the speed command ω^*The rate of increase (increase rate) depends on the speed command ω during the period in which the electric vehicle accelerates from the stopped state to the set speed.^*Is smaller than the rate of increase (increase rate), and the speed command ω^*The pitching is prevented from occurring as much as possible.
[0056]
FIG. 4 shows the speed command ω when pitching occurs.^*And the detection speed ω. In FIG. 4, pitching is detected at time t1, and the speed command ω^*Of the maximum detection speed ω_max+ Minimum detection speed ω_min) / 2, and during the suspension period T, the speed command ω^*Value (maximum detection speed ω_max+ Minimum detection speed ω_min) / 2. After the elapse of the suspension period T, the speed command ω^*The value of is increasing. In this case, during the period when the electric vehicle accelerates from the stopped state to the set speed, the speed command ω^*With respect to the rate of increase (increase rate γ1), the speed command ω^*Is increased (ratio γ2).
[0057]
As described above, in the speed command control unit 100A in the present embodiment, when the pitching detection unit 104 detects the occurrence of pitching, the speed command ω^*Is (maximum detection speed ω_max+ Minimum detection speed ω_min) / 2. For this reason, the occurrence of pitching is suppressed. At this time, since the actual speed (detected speed) ω of the electric vehicle does not greatly decrease, the driver can continue driving with a natural feeling without feeling uncomfortable.
[0058]
FIG. 5 shows a speed command ω when pitching occurs when the electric vehicle equipped with the speed control device according to the present embodiment is actually run and pitching suppression control is performed.^*FIG. 9 is a characteristic diagram illustrating an actual change state between the detection speed and the detection speed ω.
[0059]
In FIG. 5, since the occurrence of pitching is detected at time t11, the speed command ω^*At the maximum detection speed ω in the sampling period including the time t11._maxAnd minimum detection speed ω_minIs changed to a value of １ ／ of the sum of, and this value is held over the suspension period T1.
[0060]
Since the occurrence of pitching was further detected at time t12 in the suspension period T1, the speed command ω^*At the maximum detection speed ω in the sampling period including the time t12._maxAnd minimum detection speed ω_minIs changed to a value of 1/2 of the sum of, and this value is held over the suspension period T2.
[0061]
Since the occurrence of pitching was further detected at time t13 in the suspension period T2, the speed command ω^*At the maximum detection speed ω in the sampling period including the time t13._maxAnd minimum detection speed ω_minAnd holds this value over the suspension period T3.
[0062]
After the suspension period T3 has elapsed, the speed command ω^*Increase the value of. This rate of increase is smaller than the rate of increase during the period T0 in which the electric vehicle accelerates from the stopped state.
[0063]
Speed command ω^*Since the occurrence of pitching was detected again at time t14 in the middle of increasing the value of^*At the maximum detection speed ω in the sampling period including the time t14._maxAnd minimum detection speed ω_min, And this value is held over the suspension period T4.
[0064]
After the suspension period T4 has elapsed, the speed command ω^*Increase the value of. This rate of increase is smaller than the rate of increase during the period T0 in which the electric vehicle accelerates from the stopped state.
[0065]
Speed command ω^*Since the occurrence of pitching was detected again at time t15 in the middle of increasing the value of^*At the maximum detection speed ω in the sampling period including the time t15._maxAnd minimum detection speed ω_minAnd holds this value over the suspension period T5.
Note that the suspension periods T1 to T5 are the same time.
[0066]
By performing such pitching suppression control, the pitching phenomenon can be suppressed quickly and reliably, and stable traveling can be performed even on a rough road.
[0067]
Although the example of FIG. 1 is a speed control device using an induction motor as a drive motor, the present invention can be applied to a speed control device using a synchronous motor as a drive motor.
That is, by using the speed command control unit 100A shown in FIG. 1, a general-purpose vector control device for a synchronous motor, a general-purpose motor drive command control unit for a synchronous motor, an inverter, and a synchronous motor, A speed control device for suppressing and controlling the pitching phenomenon can be realized.
[0068]
Further, the present invention can be applied to a speed control device using a DC motor as a drive motor. FIG. 6 shows the outline. 6, the speed command control unit 100B is the same as the speed command control unit 100B shown in FIG. 1, but does not include the torque current command limit processing unit 103. The motor drive command control unit 300B outputs the speed command ω^*Is output in accordance with the duty command D. The current control section 400 supplies a DC current having a current value corresponding to the duty command D to the DC motor 30B. Therefore, the speed command ω output from the speed command control unit 100B^*(The value is changed when the pitching phenomenon occurs.), The speed of DC motor 30B is controlled. The detection speed ω of DC motor 30B is detected by rotation speed sensor 40B.
[0069]
【The invention's effect】
As described above, in the speed command control unit and the speed control device of the present invention, when the pitching phenomenon is detected, the value of the speed command is set to half the sum of the maximum detection speed and the minimum detection speed when pitching occurs. Since the value is changed to a value, even when the pitching travel occurs, the pitching phenomenon can be quickly suppressed and the stable travel can be performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a speed control device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a pitching detection operation.
FIG. 3 is a flowchart illustrating pitching suppression control.
FIG. 4 is a characteristic diagram illustrating a relationship between a speed command and a detected speed when pitching suppression control is performed.
FIG. 5 is a characteristic diagram showing a relationship between a speed command and a detected speed when pitching suppression control is performed in an actual electric vehicle.
FIG. 6 is a block diagram showing an embodiment of the present invention when the drive motor is a DC motor.
FIG. 7 is a block diagram showing a speed control device according to the related art.
[Explanation of symbols]
10 accelerator
20 inverter
30, 30B induction motor
40, 40B rotation speed sensor
100,100A, 100B speed command control unit
101 accelerator input processing unit
102 cm cushion processing unit
103 torque current command limit processing unit
104 pitching detector
105 speed command adjuster
200 ° vector control unit
300, 300B Motor drive command control unit
B Battery

Claims (9)

A speed command control unit that is incorporated in a speed control device of an electric vehicle that uses an electric motor as a drive source and outputs a speed command in accordance with an amount of depression of an accelerator,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
Based on a detection speed that is an actual rotation speed of the electric motor, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit A speed command adjusting unit that obtains a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed at the time of pitching and outputs the speed command to the outside, in place of the speed command generated in A speed command control unit characterized by the following. A speed command control unit that is incorporated in a speed control device of an electric vehicle that uses an electric motor as a drive source and outputs a speed command in accordance with an amount of depression of an accelerator,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit A speed command adjusting unit that obtains a speed command that is half the sum of the maximum detected speed and the minimum detected speed in the sampling period in which pitching has occurred, and outputs the speed command to the outside instead of the speed command generated in And a speed command control unit comprising: A speed command control unit that is incorporated in a speed control device of an electric vehicle that uses an electric motor as a drive source and outputs a speed command in accordance with an amount of depression of an accelerator,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit In place of the speed command generated in the above, a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed in the sampling period in which the occurrence of pitching is detected is obtained and output to the outside. A speed command control unit that holds a value of the speed command to be output to a value that is a half of the sum of the maximum detected speed and the minimum detected speed over a predetermined hold period. A speed command control unit that is incorporated in a speed control device of an electric vehicle that uses an electric motor as a drive source and outputs a speed command in accordance with an amount of depression of an accelerator,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit In place of the speed command generated in the above, a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed in the sampling period in which the occurrence of pitching is detected is obtained and output to the outside. Having a speed command adjusting unit that raises the value of the speed command after holding the value of the speed command to be output at half the value of the sum of the maximum detection speed and the minimum detection speed over a predetermined hold period, Speed command control unit. A speed command control unit that is incorporated in a speed control device of an electric vehicle that uses an electric motor as a drive source and outputs a speed command in accordance with an amount of depression of an accelerator,
An accelerator input processing unit that generates a speed command according to the accelerator depression amount;
When the detected speed, which is the actual rotation speed of the electric motor, and the speed command generated by the accelerator input processing unit are equal to or higher than a preset speed, the detected speed is sampled every predetermined sampling period, and When the difference between the maximum detection speed and the minimum detection speed during the sampling period is greater than a predetermined pitching detection level, a pitching detection unit that detects that a pitching phenomenon has occurred,
When the pitching detection unit does not detect the pitching phenomenon, the speed command generated in the accelerator input processing unit is output to the outside, while when the pitching detection unit detects the pitching phenomenon, the accelerator input processing unit In place of the speed command generated in the above, a speed command having a value that is half the sum of the maximum detection speed and the minimum detection speed in the sampling period in which the occurrence of pitching is detected is obtained and output to the outside. After holding the value of the speed command to be half of the sum of the maximum detection speed and the minimum detection speed over a predetermined hold period, the speed command value is increased, and the rate of increase is changed from when the electric vehicle is stopped. A speed command control unit having a speed command adjustment unit that makes the rate of increase smaller when accelerating. A speed controller according to any one of claims 1 to 5, a vector controller that outputs a torque current command corresponding to a speed command output from the speed command controller, and an excitation current command,
A motor drive command control unit that sends a three-phase voltage command according to the torque current command and the excitation current command to an inverter that supplies an AC current to an AC motor that is a drive source. Control device. 7. The speed control device for an electric vehicle according to claim 6, wherein the AC motor is an induction motor. 7. The speed control device for an electric vehicle according to claim 6, wherein the AC motor is a synchronous motor. A speed command control unit according to any one of claims 1 to 5, a motor drive command control unit that outputs a duty command according to the speed command output from the speed command control unit,
A current control unit that supplies a DC current corresponding to the duty command to a DC motor that is a driving source.

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