JP6953621B2 - Drive unit, drive method, drive program and electric vehicle - Google Patents

Description

The present invention relates to a drive device, a drive method, a drive program and an electric vehicle.

An electric vehicle such as a two-wheeled EV includes a motor for driving the wheels and a driving device having a control unit for controlling the motor. In an electric vehicle, it is possible to obtain a required torque from a low rotation range to a high rotation range even when the gear is fixed. Therefore, an electric vehicle without a clutch is being studied. In the case of such a clutchless electric vehicle, the motor directly receives an external force from the wheels that are disengaged by the clutch in the conventional electric vehicle.

In addition, Patent Document 1 describes a control device used for a traveling vehicle by transmitting power output from a motor to drive wheels via a transmission. This control device includes a control unit having a plurality of filters that extract signals indicating vibration or noise of a drive motor. The control unit weights the signals extracted by each filter based on the change in the vehicle state, and corrects the torque command value based on the weighted signal.

Japanese Unexamined Patent Publication No. 2016-132443

The stator of the motor of the electric vehicle is provided with a rotation position sensor for detecting the rotation position of the rotor. The control unit of the drive device receives a rising edge signal or a falling edge signal (hereinafter, collectively referred to as “sensor signal”) from the rotation position sensor for each predetermined electric angle. Based on this sensor signal, the control unit grasps the rotation speed of the motor and controls the motor.

The electric vehicle may be subject to high-frequency noise that changes faster than the acceleration / deceleration of the electric vehicle due to disturbances according to the road surface condition or the like. Especially in a clutchless electric vehicle, the external force received from the road surface is directly transmitted to the motor, so high frequency noise has a great influence on the motor control. That is, when it receives high-frequency noise, the timing of receiving the sensor signal fluctuates due to the influence. As a result, the accuracy of the time interval between the sensor signals (hereinafter, also referred to as “signal interval”) is lowered, and the motor may not be properly controlled.

In such a situation, in order to avoid the influence of high frequency noise, it is conceivable to average the values of a plurality of signal intervals and use them for motor control. However, there is a problem that the control speed of the motor is lowered.

Therefore, an object of the present invention is to provide a drive device, a drive method, a drive program, and an electric vehicle capable of appropriately driving a load without lowering the control speed of a motor.

The drive device according to the present invention is
A signal receiver that receives signals that arrive at intervals according to the rotation speed of the motor that drives the load,
The first signal interval between the reception time of the first signal most recently received by the signal receiving unit and the reception time of the second signal received before the first signal, and the second signal. Signal interval change amount calculation for calculating the signal interval change amount, which is the difference between the reception time of the signal and the reception time of the third signal received before the second signal. Department and
A signal interval correction unit that corrects the first signal interval based on the amount of change in the signal interval, and a signal interval correction unit.
A rotation speed calculation unit that calculates the instantaneous rotation speed of the motor based on the corrected first signal interval, and
A motor control unit that controls the motor based on the calculated instantaneous rotation speed,
It is characterized by having.

Further, in the drive device,
The signal interval correction unit obtains a weighting coefficient according to the signal interval change amount, multiplies the weighting coefficient by the signal interval change amount, and the signal interval change amount multiplied by the weighting coefficient is the second signal interval. The first signal interval may be corrected by adding to.

Further, in the drive device,
The weighting coefficient may be reduced as the absolute value of the signal interval change amount increases.

Further, in the drive device,
As the absolute value of the signal interval change amount increases, the decrease amount of the weighting coefficient may decrease.

Further, in the drive device,
The value of the weighting coefficient when the amount of change in the signal interval is zero may be 1.

Further, in the drive device,
The weighting coefficient is 1 when the absolute value of the signal interval change amount is within a predetermined range, and may be reduced as the absolute value increases outside the predetermined range.

Further, in the drive device,
In the rotation speed calculation unit, the second signal is a signal received immediately before the first signal, and the third signal is a signal received immediately before the second signal. If, the instantaneous rotation speed may be calculated by the following formula.
n = 60000 / (ΔTa × Np)
Here, n is the instantaneous rotation speed [rpm], ΔTa is the corrected first signal interval [mSec], and Np is the signal receiving unit while the motor makes one rotation at an electric angle. The number of the signals to be received.

Further, in the drive device,
When the signal receiving unit receives the first signal, the signal interval change amount calculation unit is a first unit counted for each monitoring time interval between the first signal and the second signal. The count difference between the count number and the second count number counted at each monitor time interval between the second signal and the third signal is calculated as the signal interval change amount.
The signal interval correction unit obtains a weighting coefficient corresponding to the count number difference, multiplies the weight coefficient by the count number difference, and adds the count number difference multiplied by the weight coefficient to the second count number. May be used to correct the first count number.

Further, in the drive device,
The monitor time interval may be shorter than the time interval of the signal received by the signal receiving unit when the rotation speed of the motor is maximum.

Further, in the drive device,
The signal interval change amount calculation unit may reset the first count number after calculating the count number difference.

Further, in the drive device,
The signal received by the signal receiving unit may be a rising edge signal or a falling edge signal of a pulse signal output from a rotation position sensor provided in the motor.

The electric vehicle according to the present invention
The drive device includes a drive device in which the load is a wheel of an electric vehicle.

In addition, in the electric vehicle,
The wheels and the motor may be mechanically connected without a clutch.

The driving method according to the present invention is
A step in which the signal receiving unit receives incoming signals at intervals according to the rotation speed of the motor that drives the load.
The signal interval change amount calculation unit is the first between the reception time of the first signal received most recently by the signal reception unit and the reception time of the second signal received before the first signal. The amount of change in the signal interval, which is the difference between the signal interval of the second signal and the second signal interval between the reception time of the second signal and the reception time of the third signal received before the second signal. And the steps to calculate
A step in which the signal interval correction unit corrects the first signal interval based on the amount of change in the signal interval.
A step in which the rotation speed calculation unit calculates the instantaneous rotation speed of the motor based on the corrected first signal interval, and
A step in which the motor control unit controls the motor based on the calculated instantaneous rotation speed,
It is characterized by having.

The drive program according to the present invention is
A step in which the signal receiving unit receives incoming signals at intervals according to the rotation speed of the motor that drives the load.
The signal interval change amount calculation unit is the first between the reception time of the first signal received most recently by the signal reception unit and the reception time of the second signal received before the first signal. The amount of change in the signal interval, which is the difference between the signal interval of the second signal and the second signal interval between the reception time of the second signal and the reception time of the third signal received before the second signal. And the steps to calculate
A step in which the signal interval correction unit corrects the first signal interval based on the amount of change in the signal interval.
A step in which the rotation speed calculation unit calculates the instantaneous rotation speed of the motor based on the corrected first signal interval, and
A step in which the motor control unit controls the motor based on the calculated instantaneous rotation speed,
Is characterized by having a computer execute the above.

In the present invention, the signal interval correction unit corrects the first signal interval based on the amount of change in the signal interval, which is the difference between the first signal interval and the second signal interval, and the rotation speed calculation unit is corrected. The instantaneous rotation speed of the motor is calculated based on the first signal interval, and the motor control unit controls the motor based on the calculated instantaneous rotation speed. Thereby, according to the present invention, the load can be appropriately driven without lowering the control speed of the motor.

It is a figure which shows the schematic structure of the electric vehicle 100 which concerns on embodiment of this invention. It is a figure which shows the schematic structure of the power conversion unit 30 and the motor 3. It is a figure which shows the magnet provided in the rotor 3r of a motor 3, and the angle sensor 4. It is a figure which shows the relationship between the rotor angle and the output of an angle sensor. It is a timing chart for demonstrating PWM control which concerns on embodiment. It is a functional block diagram of the control unit 10 of the electric vehicle control device 1. It is a figure for demonstrating the relationship between a sensor signal and a count number. It is a graph for obtaining the weighting coefficient which concerns on embodiment. It is a figure for demonstrating the calculation process of the duty ratio and the output angle of a PWM signal. (A) shows the structure of the torque map, (b) shows the structure of the duty ratio map, and (c) shows the structure of the output angle map. It is a graph for obtaining the weighting coefficient which concerns on the 1st modification. It is a graph for obtaining the weighting coefficient which concerns on the 2nd modification. It is a graph for obtaining the weighting coefficient which concerns on the 3rd modification. It is a flowchart for demonstrating an example of the electric vehicle control method which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, an electric vehicle control device for driving and controlling an electric vehicle will be described as an embodiment of the drive device according to the present invention. The drive device according to the present invention may drive a load other than the wheels of the electric vehicle.

First, the electric vehicle 100 according to the embodiment will be described with reference to FIG.

The electric vehicle 100 is a vehicle that travels by driving a motor using electric power supplied from a battery. In the present embodiment, the electric vehicle 100 is an electric two-wheeled vehicle such as an electric motorcycle. More specifically, as shown in FIG. 1, the electric two-wheeled vehicle in which the motor 3 and the wheels 8 are mechanically directly connected without a clutch. Is. The electric vehicle according to the present invention may be a vehicle in which the motor 3 and the wheels 8 are connected via a clutch. Further, the present invention is not limited to a two-wheeled vehicle, and may be, for example, a three-wheeled or four-wheeled electric vehicle.

As shown in FIG. 1, the electric vehicle 100 includes an electric vehicle control device 1, a battery 2, a motor 3, an angle sensor (rotational position sensor) 4, an accelerator position sensor 5, an assist switch 6, and a meter ( A display unit) 7, a wheel 8, and a charger 9 are provided.

Hereinafter, each component of the electric vehicle 100 will be described in detail.

The electric vehicle control device 1 is a device that controls the electric vehicle 100, and has a control unit 10, a storage unit 20, and a power conversion unit (driver) 30. The electric vehicle control device 1 may be configured as an ECU (Electronic Control Unit) that controls the entire electric vehicle 100.

Next, each component of the electric vehicle control device 1 will be described in detail.

The control unit 10 inputs information from various devices connected to the electric vehicle control device 1. Specifically, the control unit 10 receives various signals output from the battery 2, the angle sensor (rotational position sensor) 4, the accelerator position sensor 5, the assist switch 6, and the charger 9. The control unit 10 outputs a signal to be displayed on the meter 7. Further, the control unit 10 controls the motor 3 via the power conversion unit 30. The details of the control unit 10 will be described later.

The storage unit 20 stores information used by the control unit 10 (various maps described later, etc.) and a program for operating the control unit 10. The storage unit 20 is, for example, a non-volatile semiconductor memory, but is not limited thereto. The storage unit 20 may be incorporated as a part of the control unit 10.

The power conversion unit 30 converts the DC power output from the battery 2 into AC power and supplies it to the motor 3. In the present embodiment, as shown in FIG. 2, the power conversion unit 30 has an inverter composed of a three-phase full bridge circuit. The semiconductor switches Q1, Q3 and Q5 are high-side switches, and the semiconductor switches Q2, Q4 and Q6 are low-side switches. The control terminals of the semiconductor switches Q1 to Q6 are electrically connected to the control unit 10. The semiconductor switches Q1 to Q6 are, for example, MOSFETs, IGBTs, or the like.

As shown in FIG. 2, a smoothing capacitor C is provided between the power supply terminal 30a and the power supply terminal 30b.

The input terminal 3a is a U-phase input terminal of the motor 3, the input terminal 3b is a V-phase input terminal of the motor 3, and the input terminal 3c is a W-phase input terminal of the motor 3.

As shown in FIG. 2, the semiconductor switch Q1 is connected between the power supply terminal 30a to which the positive electrode of the battery 2 is connected and the input terminal 3a of the motor 3. Similarly, the semiconductor switch Q3 is connected between the power supply terminal 30a and the input terminal 3b of the motor 3. The semiconductor switch Q5 is connected between the power supply terminal 30a and the input terminal 3c of the motor 3.

The semiconductor switch Q2 is connected between the input terminal 3a of the motor 3 and the power supply terminal 30b to which the negative electrode of the battery 2 is connected. Similarly, the semiconductor switch Q4 is connected between the input terminal 3b of the motor 3 and the power supply terminal 30b. The semiconductor switch Q6 is connected between the input terminal 3c of the motor 3 and the power supply terminal 30b.

The battery 2 supplies electric power to the motor 3 that rotates the wheels 8 of the electric vehicle 100. The battery 2 supplies DC power to the power conversion unit 30. The battery 2 is, for example, a lithium ion battery, but may be another type of battery. The number of batteries 2 is not limited to one, and may be plural. That is, the electric vehicle 100 may be provided with a plurality of batteries 2 connected in parallel or in series with each other. Further, the battery 2 may include a lead battery for supplying an operating voltage to the control unit 10.

The battery 2 includes a battery management unit (BMU). The battery management unit transmits battery information regarding the voltage of the battery 2 and the state (charge rate, etc.) of the battery 2 to the control unit 10.
The motor 3 is a motor that drives a load such as wheels 8 by alternating current power supplied from the power conversion unit 30. In this embodiment, the motor 3 is mechanically connected to the wheels 8 to rotate the wheels 8 in a desired direction. The motor 3 is a three-phase AC motor having a U phase, a V phase, and a W phase. As described above, the motor 3 is mechanically directly connected to the wheels 8 without the intervention of a clutch. In the present embodiment, a three-phase brushless motor is used as the three-phase AC motor, but the type of the motor 3 is not limited to this.

The angle sensor 4 is a sensor that detects the rotational position of the rotor 3r of the motor 3. As shown in FIG. 3, N-pole and S-pole magnets (sensor magnets) are alternately attached to the peripheral surface of the rotor 3r. The angle sensor 4 is composed of, for example, a Hall element, and detects a change in the magnetic field accompanying the rotation of the motor 3. The number of magnets shown in FIG. 3 is an example and is not limited to this. Further, the magnet may be provided inside the flywheel (not shown).

As shown in FIG. 3, the angle sensor 4 includes a U-phase angle sensor 4u associated with the U-phase of the motor 3, a V-phase angle sensor 4v associated with the V-phase of the motor 3, and a W of the motor 3. It has a W-phase angle sensor 4w associated with a phase. The angle sensors 4u, 4v, 4w of each phase are provided in the motor 3. In the present embodiment, the U-phase angle sensor 4u and the V-phase angle sensor 4v are arranged so as to form an angle of 30 ° with respect to the rotor 3r. Similarly, the V-phase angle sensor 4v and the W-phase angle sensor 4w are arranged so as to form an angle of 30 ° with respect to the rotor 3r of the motor 3.

As shown in FIG. 4, the U-phase angle sensor 4u, the V-phase angle sensor 4v, and the W-phase angle sensor 4w output a pulse signal having a phase corresponding to the rotation position of the rotor 3r. The width of this pulse signal (or the time interval of the sensor signal) becomes narrower as the rotation speed of the motor 3 (that is, the wheel 8) increases.

As shown in FIG. 4, a number indicating a motor stage (motor stage number) is assigned to each predetermined rotation position. The motor stage indicates the rotation position of the rotor 3r, and in the present embodiment, the motor stage numbers 1, 2, 3, 4, 5, and 6 are assigned for each electric angle of 60 °.

The output stage, also called an energization stage, is a motor stage detected by the angle sensor 4 plus a time based on the output angle. The output angle changes according to the rotation speed of the motor 3 and the target torque as described later.

The control unit 10 uses the PWM signal to control the semiconductor switches Q1 to Q6 of the power conversion unit 30 on and off. As a result, the DC power supplied from the battery 2 is converted into AC power. In the present embodiment, as shown in FIG. 5, the U-phase low-side switch (semiconductor switch Q2) is PWM-controlled at the output stages 6, 1, 2, and 3. The V-phase low-side switch (semiconductor switch Q4) is PWM-controlled in the output stages 2, 3, 4, 5 and the W-phase low-side switch (semiconductor switch Q6) is PWM-controlled in the output stages 4, 5, 6, 1. .. The stage on which PWM control is performed is determined by the energization method or the like, and is not limited to this example.

By controlling the low-side switch on and off instead of the high-side switch as described above, it is possible to prevent the current generated by the regenerative operation of the motor 3 from flowing into the battery 2. If the inflow of the regenerative current into the battery 2 is allowed, the high side switch may be on / off controlled.

As shown in FIG. 5, there is a timing when the high side switch is also turned on. For example, the semiconductor switch Q1 which is a U-phase high-side switch is on-controlled at predetermined time intervals in the output stages 1 and 2. By controlling the high side switch on in this way, it is possible to suppress heat generation in the power conversion unit 30. In order to prevent a current short circuit, when the high side switch is controlled to be on, the corresponding low side switch (that is, of the same arm) is controlled to be off.

The accelerator position sensor 5 detects the amount of operation of the electric vehicle 100 with respect to the accelerator (hereinafter, referred to as “accelerator operation amount”) and transmits it as an electric signal to the control unit 10. The accelerator operation amount corresponds to the throttle opening of the engine vehicle. When the user wants to accelerate, the accelerator operation amount becomes large, and when the user wants to decelerate, the accelerator operation amount becomes small.

The assist switch 6 is a switch that is operated when the user requests assistance for the electric vehicle 100. When the assist switch 6 is operated by the user, the assist switch 6 transmits an assist request signal to the control unit 10. Then, the control unit 10 controls the motor 3 to generate an assist torque.

The meter (display unit) 7 is a display (for example, a liquid crystal panel) provided on the electric vehicle 100, and displays various information. The meter 7 is provided, for example, on the handle (not shown) of the electric vehicle 100. Information such as the traveling speed of the electric vehicle 100, the remaining amount of the battery 2, the current time, the total traveling distance, and the remaining traveling distance is displayed on the meter 7. The remaining mileage indicates how far the electric vehicle 100 can travel.

The charger 9 has a power plug (not shown) and a converter circuit (not shown) that converts an AC power supply supplied through the power plug into a DC power supply. The battery 2 is charged by the DC power converted by the converter circuit. The charger 9 is communicably connected to the electric vehicle control device 1 via, for example, a communication network (CAN or the like) in the electric vehicle 100.

Next, the control unit 10 of the electric vehicle control device 1 will be described in detail.

As shown in FIG. 6, the control unit 10 includes a signal receiving unit 11, a signal interval change amount calculation unit 12, a signal interval correction unit 13, a rotation speed calculation unit 14, and a motor control unit 15. There is. The processing in each unit of the control unit 10 can be realized by software (program).

The signal receiving unit 11 receives signals that arrive at intervals according to the rotation speed of the motor 3. A plurality of signals are output from the angle sensor 4 while the motor 3 makes one rotation. More specifically, the signal receiving unit 11 receives the sensor signals (that is, the rising edge signal or the falling edge signal of the pulse signal) output from the U-phase angle sensor 4u, the V-phase angle sensor 4v, and the W-phase angle sensor 4w. do. In the present embodiment, the signal receiving unit 11 receives the sensor signal every time the rotor 3r of the motor 3 rotates by 60 ° at an electric angle. As the rotation speed of the motor 3 increases, the time interval at which the sensor signal arrives becomes shorter.

As shown in FIG. 7, the signal receiving unit 11 confirms whether or not the sensor signal is received from the angle sensor 4 at each monitor time interval Δtm. The monitor time interval Δtm is, for example, the control time interval of the motor 3. The sensor signal may be received by interrupt processing from the angle sensor 4.

The monitor time interval Δtm is shorter than the time interval of the sensor signal received by the signal receiving unit 11 when the electric vehicle 100 travels at the maximum speed, for example, 50 microseconds. More generally, the monitor time interval Δtm is shorter than the time interval of the sensor signal received by the signal receiving unit 11 when the rotation speed of the motor 3 is maximum.

The signal interval change amount calculation unit 12 calculates the signal interval change amount, which is the change amount of the signal interval (also referred to as the inter-sensor time). As shown in FIG. 7, the amount of change in the signal interval is the difference (ΔT2-ΔT1) between the first signal interval ΔT1 and the second signal interval ΔT2. Here, the first signal interval ΔT1 is a time interval between the reception time of the sensor signal S1 (first signal) and the reception time of the sensor signal S2 (second signal). The sensor signal S1 is a sensor signal most recently received by the signal receiving unit 11. "Nearest" means the closest to the current time. The sensor signal S2 is a sensor signal received immediately before the sensor signal S1. The second signal interval ΔT2 is a time interval between the reception time of the sensor signal S2 and the reception time of the sensor signal S3 (third signal). The sensor signal S3 is a sensor signal received immediately before the sensor signal S2. The signal interval is not limited to the time interval between consecutive signals, and may be the time interval between two or more signals of every other signal.

In the present embodiment, the signal interval change amount calculation unit 12 calculates the difference value of the count number as the signal interval change amount. That is, when the signal receiving unit 11 does not receive the sensor signal, the signal receiving unit 11 or the signal interval change amount calculation unit 12 increases the number of counts. This count number indicates the time elapsed since the latest sensor signal was received. The initial value of the count number is 0. On the other hand, when the signal receiving unit 11 receives the sensor signal, the signal interval change amount calculation unit 12 receives the first count number N1 counted for each monitor time interval Δtm between the sensor signal S1 and the sensor signal S2. The count difference ΔN (= N1-N2) between the second count number N2 counted for each monitor time interval Δtm between the sensor signal S2 and the sensor signal S3 is calculated as the signal interval change amount.

The signal interval change amount calculation unit 12 resets the first count number N1 (that is, returns to the initial value) after calculating the count number difference.

The signal interval correction unit 13 corrects the first signal interval ΔT1 based on the signal interval change amount calculated by the signal interval change amount calculation unit 12. As will be described later, the first signal interval ΔT1 is corrected so as to suppress the influence of high frequency noise that changes faster than the acceleration or deceleration of the electric vehicle 100.

The correction of the first signal interval ΔT1 according to the present embodiment will be described in detail.

First, the signal interval correction unit 13 obtains a weighting coefficient C according to the amount of change in the signal interval. The weighting coefficient C can be obtained by referring to a graph showing the relationship between the amount of change in the signal interval and the weighting coefficient C. In the present embodiment, the weighting coefficient C is obtained by referring to a graph showing the relationship between the count difference ΔN and the weighting coefficient C, as shown in FIG. This graph is stored in the storage unit 20 in advance in the form of a table or a mathematical formula. In the case of the table format, the weighting coefficient C is obtained by linear interpolation or the like. As shown in FIG. 8, the weighting coefficient C is set to decrease as the absolute value of the signal interval change amount (count difference ΔN) increases. Further, when the signal interval change amount is zero (when ΔN = 0), the weighting coefficient C is 1.

After obtaining the weighting coefficient C as described above, the signal interval correction unit 13 multiplies the weighting coefficient C by the amount of change in the signal interval. That is, C × (ΔT1-ΔT2) is calculated. In the case of this embodiment, C × ΔN is calculated. Then, the amount of change in the signal interval multiplied by the weighting coefficient C is added to the second signal interval ΔT2. As a result, the corrected first signal interval ΔTa is obtained. That is, the corrected first signal interval ΔTa is obtained by the equation (1).
ΔTa = C × (ΔT1-ΔT2) + ΔT2 ・ ・ ・ (1)

When the count number is used as the signal interval, the count number Na, which is the corrected first count number N1, is obtained by the equation (2).
Na = CΔN + N2 ... (2)

The rotation speed calculation unit 14 calculates the instantaneous rotation speed of the motor 3 based on the first signal interval ΔTa corrected by the signal interval correction unit 13. Specifically, the rotation speed calculation unit 14 calculates the instantaneous rotation speed of the motor 3 according to the equation (3).
n = 60000 / (ΔTa × Np) ・ ・ ・ (3)
Here, n is the instantaneous rotation speed [rpm] of the motor 3, ΔTa is the corrected first signal interval [mSec], and Np is the signal receiving unit 11 while the motor 3 makes one rotation at the electric angle. Is the number of sensor signals received by.

When the count number is used, the rotation speed calculation unit 14 calculates the instantaneous rotation speed of the motor 3 according to the equation (4).
n = 60000 / (NaΔtm × Np) ・ ・ ・ (4)
Here, n is the instantaneous rotation speed [rpm] of the motor 3, Na is the corrected count number, Δtm is the monitor time interval [mSec], and Np is the period during which the motor 3 makes one rotation at the electric angle. Is the number of sensor signals received by the signal receiving unit 11.

The motor control unit 15 controls the motor 3 based on the instantaneous rotation speed calculated by the rotation speed calculation unit 14. The motor control unit 15 transmits a control signal to the semiconductor switches Q1 to Q6 of the power conversion unit 30. More specifically, the motor control unit 15 generates a PWM signal having a duty ratio calculated based on the target torque and the instantaneous rotation speed of the motor 3, and is calculated based on the target torque and the instantaneous rotation speed of the motor 3. It is output to the power conversion unit 30 at the output angle. As a result, the motor 3 is controlled to generate the target torque. The PWM signal is generated every monitor time interval or every time a sensor signal is received.

The calculation of the duty ratio and the output angle will be described in detail with reference to FIGS. 9 and 10. The motor control unit 15 acquires the target torque by searching the torque map M1 using the accelerator operation amount received from the accelerator position sensor 5 and the instantaneous rotation speed calculated by the rotation speed calculation unit 14. Here, as shown in FIG. 10A, the torque map M1 is a map showing the relationship between the accelerator operation amount, the rotation speed of the motor 3, and the target torque of the motor 3.

Next, the motor control unit 15 acquires the duty ratio by searching the duty ratio map M2 using the target torque acquired from the torque map M1 and the instantaneous rotation speed calculated by the rotation speed calculation unit 14. .. Here, as shown in FIG. 10B, the duty ratio map M2 is a map showing the relationship between the target torque of the motor 3, the rotation speed of the motor 3, and the duty ratio of the PWM signal.

Further, the motor control unit 15 acquires the output angle by searching the output angle map M3 using the target torque acquired from the torque map M1 and the instantaneous rotation speed calculated by the rotation speed calculation unit 14. Here, as shown in FIG. 10C, the output angle map M3 is a map showing the relationship between the target torque of the motor 3, the rotation speed of the motor 3, and the output angle of the PWM signal.

When the control unit 10 controls the power conversion unit 30 using a plurality of energization methods (for example, 120 ° energization method and 180 ° energization method), the duty ratio map M2 and the output angle map M3 correspond to each energization method. Is used. That is, when the 120 ° energization method is used, the duty ratio and the output angle are acquired using the duty ratio map and the output angle map for the 120 ° energization method, and when the 180 ° energization method is used, the 180 ° energization method is used. The duty ratio and output angle are obtained using the duty ratio map and output angle map of.

The PWM signal having the duty ratio acquired as described above is output to the power conversion unit 30 at the output angle acquired as described above, and the semiconductor switches Q1 to Q6 are on / off controlled. As a result, the motor 3 is controlled to generate a desired torque.

As described above, in the electric vehicle control device 1 according to the present embodiment, the signal interval correction unit 13 corrects the first signal interval ΔT1 based on the signal interval change amount (ΔT1-ΔT2), and calculates the rotation speed. The unit 14 calculates the instantaneous rotation speed of the motor 3 based on the corrected first signal interval ΔTa. Then, the motor control unit 15 controls the motor 3 based on the calculated instantaneous rotation speed. As a result, the wheels 8 of the electric vehicle 100 can be appropriately driven.

In the present embodiment, the first signal interval ΔT1 is corrected and corrected based on the signal interval change amount (ΔT1-ΔT2) and the weighting coefficient C that decreases as the absolute value of the signal interval change amount increases. The instantaneous rotation speed of the motor 3 is calculated based on the signal interval ΔTa of 1. This makes it possible to reduce the sensitivity of the instantaneous rotation speed used for motor control to high-frequency noise. Therefore, even when the first signal interval ΔT1 fluctuates greatly due to high frequency noise, the first signal interval is corrected to an appropriate value, so that appropriate motor control is performed to drive the wheel 8 which is a load. can do.

Further, according to the present embodiment, as described above, the influence of high frequency noise can be suppressed without obtaining the average value of the signal intervals, so that the control speed of the motor 3 is not lowered.

Therefore, according to the present embodiment, the load can be appropriately driven without lowering the control speed of the motor 3.

The graph for obtaining the weighting coefficient C is not limited to that shown in FIG. Some modifications will be described below.

FIG. 11 shows a graph of the weighting coefficient C according to the first modification. In this modification, the weighting coefficient C is 1 in the range where the count difference ΔN is −α or more and + α or less, and the weighting coefficient becomes smaller as the difference is out of the range. That is, the weighting coefficient C is 1 when the absolute value of the signal interval change amount is within a predetermined range (0 ± α), and decreases as the absolute value of the signal interval change amount increases when it is outside the predetermined range. Become. By using such a weighting coefficient C, when the amount of change in the signal interval is relatively small, the instantaneous rotation speed of the motor 3 is calculated by using the first signal interval ΔT1 as it is. As a result, the change in the signal interval not caused by the high frequency noise can be directly reflected in the control of the motor 3.

FIG. 12 shows a graph of the weighting coefficient C according to the second modification. In this modification, the decrease in the weighting coefficient C decreases as the absolute value of the signal interval change increases. In other words, the curve of the weighting factor C has a downwardly convex shape. By using such a weighting coefficient C, the amount of change in the signal interval can be sufficiently suppressed even when a sudden external force is applied to the load.

FIG. 13 shows a graph of the weighting coefficient C according to the third modification. This modification is a combination of the first modification and the second modification. That is, the weighting coefficient C is 1 in the range where the count difference ΔN is −α or more and + α or less, and becomes smaller so that the amount of decrease in the weighting coefficient C becomes smaller as it deviates from the range. By using such a weighting coefficient C, the change in signal interval not caused by high frequency noise can be directly reflected in the control of the motor 3, and the amount of change in signal interval is sufficient even when a sudden external force is applied to the load. Can be suppressed.

<Electric vehicle control method>
Next, an example of the electric vehicle control method according to the present embodiment will be described with reference to the flowchart of FIG. It is assumed that the count number has been initialized in advance.

The signal receiving unit 11 determines whether or not the monitor time interval Δtm has elapsed (step S11). When the monitor time interval Δtm has elapsed (S11: Yes), it is determined whether or not the sensor signal has been received from the angle sensor 4 (step S12). When the sensor signal is not received (S12: No), the count number is increased by one (step S13), and the process returns to step S11.

On the other hand, when the sensor signal is received (S12: Yes), the signal interval change amount calculation unit 12 calculates the count difference ΔN between the current count number N1 and the previous count number N2 (step S14). ). Here, the current count number N1 is the count number counted between the sensor signal S1 and the sensor signal S2, and the previous count number N2 is counted between the sensor signal S2 and the sensor signal S3. It is a count number.

After calculating the count number difference ΔN, the signal interval change amount calculation unit 12 resets the count number N1 to the initial value (step S15). The count number N1 may be reset at any timing of steps S16 to S19.

Next, the signal interval correction unit 13 obtains the weighting coefficient C according to the count number difference ΔN calculated in step S14 (step S16). Then, the signal interval correction unit 13 corrects the count number N1 this time (step S17). Specifically, the corrected first count number N1 (that is, the count number Na) is calculated using the above equation (2).

Next, the rotation speed calculation unit 14 calculates the instantaneous rotation speed of the motor 3 based on the count number Na calculated in step S17 (step S18). Specifically, the instantaneous rotation speed of the motor 3 is calculated using the above equation (4). Then, the motor control unit 15 controls the motor 3 based on the instantaneous rotation speed calculated in step S18 (step S19). Specifically, as described with reference to FIGS. 9 and 10, a PWM signal for obtaining a predetermined torque is generated and output to the power conversion unit 30.

Although the count number is used in the above processing flow, the signal interval change amount may be calculated by using the reception time of the sensor signal. Further, when the sensor signal is not received (S12: No), the duty ratio is acquired from the duty ratio map M2 using the latest accelerator operation amount and the instantaneous rotation speed calculated last time, and the power conversion unit 30 The PWM signal transmitted to may be updated.

At least a part of the electric vehicle control device 1 (control unit 10) described in the above-described embodiment may be configured by hardware or software. In the case of software configuration, a program that realizes at least a part of the functions of the control unit 10 may be stored in a recording medium such as a flexible disk or a CD-ROM, read by a computer, and executed. The recording medium is not limited to a removable one such as a magnetic disk or an optical disk, and may be a fixed recording medium such as a hard disk device or a memory.

Further, a program that realizes at least a part of the functions of the control unit 10 may be distributed via a communication line (including wireless communication) such as the Internet. Further, the program may be encrypted, modulated, compressed, and distributed via a wired line or wireless line such as the Internet, or stored in a recording medium.

Based on the above description, those skilled in the art may be able to conceive of additional effects and various modifications of the present invention, but aspects of the present invention are not limited to the individual embodiments described above. .. Components across different embodiments may be combined as appropriate. Various additions, changes and partial deletions are possible without departing from the conceptual idea and purpose of the present invention derived from the contents defined in the claims and their equivalents.

1 Electric vehicle control device 2 Battery 3 Motor 3r Rotor 4 Angle sensor 4u U-phase angle sensor 4v V-phase angle sensor 4w W-phase angle sensor 5 Accelerator position sensor 6 Assist switch 7 Meter 8 Wheels 9 Charger 10 Control unit 11 Signal receiver 12 Signal interval change amount calculation unit 13 Signal interval correction unit 14 Rotation speed calculation unit 15 Motor control unit 20 Storage unit 30 Power conversion unit 100 Electric vehicle M1 Torque map M2 Duty ratio map M3 Output angle map Q1, Q2, Q3, Q4 Q5, Q6 Semiconductor switches S1, S2, S3 Sensor signals

Claims (15)

A signal receiver that receives signals that arrive at intervals according to the rotation speed of the motor that drives the load,
The first signal interval between the reception time of the first signal most recently received by the signal receiving unit and the reception time of the second signal received before the first signal, and the second signal. Signal interval change amount calculation for calculating the signal interval change amount, which is the difference between the reception time of the signal and the reception time of the third signal received before the second signal. Department and
A signal interval correction unit that corrects the first signal interval based on the amount of change in the signal interval, and a signal interval correction unit.
A rotation speed calculation unit that calculates the instantaneous rotation speed of the motor based on the corrected first signal interval, and
A motor control unit that controls the motor based on the calculated instantaneous rotation speed,
A drive device characterized by being provided with. The signal interval correction unit obtains a weighting coefficient according to the signal interval change amount, multiplies the weighting coefficient by the signal interval change amount, and the signal interval change amount multiplied by the weighting coefficient is the second signal interval. The driving device according to claim 1, wherein the first signal interval is corrected by adding to the above. The driving device according to claim 2, wherein the weighting coefficient decreases as the absolute value of the signal interval change amount increases. The driving device according to claim 3, wherein the decrease amount of the weighting coefficient decreases as the absolute value of the signal interval change amount increases. The driving device according to claim 3, wherein the value of the weighting coefficient is 1 when the signal interval change amount is zero. The weighting coefficient is 1. Drive device. In the rotation speed calculation unit, the second signal is a signal received immediately before the first signal, and the third signal is a signal received immediately before the second signal. The driving device according to claim 1, wherein the instantaneous rotation speed is calculated by the following formula.
n = 60000 / (ΔTa × Np)
Here, n is the instantaneous rotation speed [rpm], ΔTa is the corrected first signal interval [mSec], and Np is the signal receiving unit while the motor makes one rotation at an electric angle. The number of the signals to be received. When the signal receiving unit receives the first signal, the signal interval change amount calculation unit is a first unit counted for each monitoring time interval between the first signal and the second signal. The count difference between the count number and the second count number counted at each monitor time interval between the second signal and the third signal is calculated as the signal interval change amount.
The signal interval correction unit obtains a weighting coefficient corresponding to the count number difference, multiplies the weight coefficient by the count number difference, and adds the count number difference multiplied by the weight coefficient to the second count number. The driving device according to claim 1, wherein the first count number is corrected by the above method. The driving device according to claim 8, wherein the monitor time interval is shorter than the time interval of the signal received by the signal receiving unit when the rotation speed of the motor is maximum. The driving device according to claim 8, wherein the signal interval change amount calculation unit resets the first count number after calculating the count number difference. The drive device according to claim 1, wherein the signal received by the signal receiving unit is a rising edge signal or a falling edge signal of a pulse signal output from a rotation position sensor provided in the motor. .. The electric vehicle according to claim 1, further comprising a drive device in which the load is a wheel of the electric vehicle. The electric vehicle according to claim 12, wherein the wheels and the motor are mechanically connected without a clutch. A step in which the signal receiving unit receives incoming signals at intervals according to the rotation speed of the motor that drives the load.
The signal interval change amount calculation unit is the first between the reception time of the first signal received most recently by the signal reception unit and the reception time of the second signal received before the first signal. The amount of change in the signal interval, which is the difference between the signal interval of the second signal and the second signal interval between the reception time of the second signal and the reception time of the third signal received before the second signal. And the steps to calculate
A step in which the signal interval correction unit corrects the first signal interval based on the amount of change in the signal interval.
A step in which the rotation speed calculation unit calculates the instantaneous rotation speed of the motor based on the corrected first signal interval, and
A step in which the motor control unit controls the motor based on the calculated instantaneous rotation speed,
A driving method characterized by being provided with. A step in which the signal receiving unit receives incoming signals at intervals according to the rotation speed of the motor that drives the load.
The signal interval change amount calculation unit is the first between the reception time of the first signal received most recently by the signal reception unit and the reception time of the second signal received before the first signal. The amount of change in the signal interval, which is the difference between the signal interval of the second signal and the second signal interval between the reception time of the second signal and the reception time of the third signal received before the second signal. And the steps to calculate
A step in which the signal interval correction unit corrects the first signal interval based on the amount of change in the signal interval.
A step in which the rotation speed calculation unit calculates the instantaneous rotation speed of the motor based on the corrected first signal interval, and
A step in which the motor control unit controls the motor based on the calculated instantaneous rotation speed,
A drive program characterized by having a computer execute.

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