TW201945220A - Drive device, drive method, drive program, and electric vehicle - Google Patents

Abstract

An electric vehicle control device 1 according to an embodiment is provided with: a signal receiving unit 11 for receiving a signal coming at intervals in accordance with the rotational speed of a motor 3; a signal interval variation calculation unit 12 for calculating a signal interval variation that is the difference between a first signal interval [Delta]T1 and a second signal interval [Delta]T2; a signal interval correction unit 13 for correcting the first signal interval [Delta]T1 on the basis of the signal interval variation; a rotational speed calculation unit 14 for calculating an instantaneous rotational speed of the motor 3 on the basis of the corrected first signal interval [Delta]Ta; and a motor control unit 15 for controlling the motor 3 on the basis of the calculated instantaneous rotational speed.

Description

Driving device, driving method, driving program and electric vehicle

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

Electric vehicles such as electric two-wheeled vehicles (two-wheel EVs) generally include a motor for driving wheels and a driving device having a control section for controlling the motor. Since electric vehicles can obtain the required torque from the low-revolution range to the high-revolution range when the gear is fixed, the industry is currently researching electric vehicles without a clutch. For such a clutchless electric vehicle, its motor will directly withstand the external force from the outside of the wheel that was blocked by the clutch in conventional electric vehicles.

Patent Document 1 describes a control device for a vehicle traveling by transmitting power output from a motor to a drive wheel via a gearbox. The control unit included in the control device includes a plurality of filters for extracting signals indicating vibration or noise of the drive motor. The control unit adds weights to the signals extracted by the filters according to changes in the vehicle state, and corrects the torque command value based on the weighted signals.

[Advanced technical literature]

[Patent Document 1] Patent Publication No. 2016-132443

At the stator of the electric vehicle motor, a rotation position sensor for detecting a rotation position of the rotor is provided. The control unit of the driving device receives a rising edge signal or a falling edge signal (hereinafter also referred to as a "sensor signal") from the rotary position sensor at each predetermined electrical angle. The control unit grasps the rotation speed of the motor based on the sensor signal and controls the motor.

An electric vehicle may receive high-frequency noise that changes earlier than the acceleration and deceleration of the electric vehicle due to disturbances such as road conditions. Especially for electric vehicles without clutches, since the motor will directly withstand external forces from the road, high-frequency noise will have a great impact on motor control. That is, once high-frequency noise is received, it will sway at the time point when the sensor signal is received due to its influence. As a result, the accuracy of the time interval between sensor signals (hereinafter also referred to as the "signal interval") is reduced, making it impossible to perform appropriate motor control.

In order to avoid the influence of high frequency noise, you can consider averaging the values of multiple signal intervals and then use it for motor control. However, in this case, the problem that the speed of the motor control is reduced will arise.

An object of the present invention is to provide a driving device, a driving method, a driving program, and an electric vehicle, which can appropriately drive a load without reducing the control speed of the motor.

The driving device according to the present invention is characterized by comprising:

The signal receiving unit receives signals that arrive at intervals corresponding to the rotation speed of the motor driving the load;

The signal interval change amount calculation unit calculates a signal interval change amount which is the difference between the first signal interval and the second signal interval. The first signal interval is the reception time point of the first signal just received by the signal receiving unit and The signal interval between the reception time point of the second signal received earlier than the first signal, and the second signal interval is the time interval between the reception time point of the second signal and the third signal received earlier than the second signal. Signal interval between receiving time points;

The signal interval correction section corrects the first signal interval according to the signal interval variation;

The rotation speed calculation unit calculates the instantaneous rotation speed of the motor based on the corrected first signal interval; and

The motor control unit controls the motor based on the calculated instantaneous rotation speed.

In the driving device, the signal interval correction unit obtains a weight coefficient corresponding to the signal interval change amount, multiplies the weight coefficient by the signal interval change amount, and multiplies the signal interval change amount by the weight coefficient. Add to the second signal interval to correct the first signal interval.

In the driving device, the weight coefficient becomes smaller as the absolute value of the change amount of the signal interval becomes larger.

In the driving device, the reduction amount of the weight coefficient becomes smaller as the absolute value of the change amount of the signal interval becomes larger.

In the driving device, the value of the weighting coefficient when the signal interval change amount is 0 is 1.

In the driving device, when the absolute value of the change amount of the signal interval is within the prescribed range, the weight coefficient is 1, and when the absolute value of the change amount of the signal interval is outside the prescribed range, the weight coefficient becomes smaller as the absolute value becomes larger.

In the drive device, in the case where the second signal is the signal received before the first signal and the third signal is the signal received before the second signal, the rotation speed calculation section uses the following formula Calculate instantaneous rotation speed:
n = 60000 / (ΔTa × Np)

In the above formula, n represents the instantaneous rotation speed (rpm), ΔTa represents the first signal interval (mSec) after correction, and Np represents the number of signals received by the signal receiving section during a period of one rotation of the motor at an electrical angle.

In the driving device, when the signal receiving unit receives the first signal, the signal interval change calculation unit will: The first count number after counting between the first signal and the second signal according to the monitoring time interval and the The difference between the counted number between the second signal and the third signal after the second counted number is counted according to the monitoring time interval is calculated as the change amount of the signal interval. The signal interval correction unit obtains a value corresponding to the difference in the counted number by: And multiplying the weight coefficient by the difference between the counts, and adding the difference between the counts after multiplying the weight coefficient and the second count, to correct the first count.

In the driving device, the monitoring time interval is shorter than the time interval of the signal received by the signal receiving section when the rotation speed of the motor is at the maximum.

In the driving device, the signal interval change amount calculation unit resets the first count number after calculating the difference in count numbers.

In the driving device, 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 rotary position sensor provided at the motor.

The electric vehicle according to the present invention is characterized in that it includes a driving device described in item 1 of the scope of patent application and the load is a wheel of the electric vehicle.

In electric vehicles, the wheels and the motor are mechanically connected without passing through a clutch.

The driving method according to the present invention is characterized by comprising:

The step of the signal receiving unit receiving a signal that arrives at an interval corresponding to the rotation speed of the motor that drives the load; the signal interval variation calculation unit calculates the amount of the signal interval change that is the difference between the first signal interval and the second signal interval. Step, the first signal interval is the signal interval between the reception time point of the first signal just received by the signal receiving section and the reception time point of the second signal received earlier than the first signal, and the second signal interval Is the signal interval between the reception time point of the second signal and the reception time point of the third signal received earlier than the second signal; the signal interval correction section corrects the first signal interval according to the change amount of the signal interval A step of calculating the instantaneous rotation speed of the motor based on the corrected first signal interval by the rotation speed calculation unit; and a step of controlling the motor by the motor control unit based on the calculated instantaneous rotation speed.

The driver according to the present invention is characterized by:

Steps for the computer to execute: a step in which the signal receiving section receives a signal that arrives at an interval corresponding to the rotation speed of the motor driving the load; the signal interval variation calculating section calculates a signal that is the difference between the first signal interval and the second signal interval In the step of the interval change amount, the first signal interval is a signal interval between the reception time point of the first signal just received by the signal receiving section and the reception time point of the second signal received earlier than the first signal. The second signal interval is a signal interval between the reception time point of the second signal and the reception time point of the third signal received earlier than the second signal; the signal interval correction unit performs an interval on the first signal according to the variation amount of the signal interval A step of performing correction; a step of calculating the instantaneous rotational speed of the motor based on the first signal interval after the correction; and a step of controlling the motor by the motor control portion based on the calculated instantaneous rotational speed.

Invention effect

In the present invention, the signal interval correction unit corrects the first signal interval based on a signal interval change amount which is a difference between the first signal interval and the second signal interval, and the rotation speed calculation unit calculates the first signal interval after the correction According to the instantaneous rotation speed of the motor, the motor control unit controls the motor based on the calculated instantaneous rotation speed. By doing so, it is possible to appropriately drive the load without reducing the control speed of the motor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, an electric vehicle control device that drives and controls an electric vehicle will be described as one embodiment of the drive device according to the present invention. Among them, the driving device according to the present invention may drive loads other than the wheels of an electric vehicle.

First, the electric vehicle 100 according to the embodiment will be described with reference to FIG. 1.

The electric vehicle 100 travels by driving a motor using electric power supplied from a battery. In this embodiment, the electric vehicle 100 is an electric two-wheeled vehicle such as an electric motorcycle, specifically, the electric two after the motor 3 and the wheel 8 are directly mechanically connected without a clutch as shown in FIG. 1. Wheeler. 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, it is not limited to two-wheeled vehicles, but may be, for example, three- or four-wheeled electric vehicles.

The electric vehicle 100, as shown in FIG. 1, 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 auxiliary switch 6, and an instrument ( Display) 7, wheels 8, and charger 9.

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

Hereinafter, 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 auxiliary switch 6, and the charger 9. The control unit 10 outputs a signal displayed on the instrument 7. In addition, the control unit 10 controls the motor 3 through the power conversion unit 30. Details of the control unit 10 will be described later.

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

The power conversion unit 30 converts DC power output from the battery 2 into AC power and supplies the AC power to the motor 3. In this embodiment, as shown in FIG. 2, the power conversion unit 30 includes an inverter configured by a three-phase full-bridge circuit. Semiconductor switches Q1, Q3, and Q5 are high-end switches, and semiconductor switches Q2, Q4, and Q6 are low-end 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 or IGBTs.

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

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

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

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

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

Battery 2 contains a battery management unit (BMU). The battery management unit sends a battery message related to the voltage and status (charging rate, etc.) of the battery 2 to the control unit 10.

The motor 3 drives a load such as a wheel 8 by AC power supplied from the power conversion unit 30. In this embodiment, the motor 3 is mechanically connected to the wheel 8 so that the wheel 8 is rotated in a desired direction. The motor 3 is a three-phase AC motor having U-phase, V-phase, and W-phase. As described, the motor 3 and the wheels 8 are directly mechanically connected without passing through a clutch. However, although a three-phase brushless motor is used as the three-phase AC motor in this embodiment, the type of the motor 3 is not limited to this.

The angle sensor 4 is used to detect the rotation position of the rotor 3 r of the motor 3. As shown in FIG. 3, N-pole and S-pole magnets (sensor magnets) are alternately mounted on the outer peripheral surface of the rotor 3r. The angle sensor 4 is configured by, for example, a Hall element, and detects a change in a magnetic field accompanying rotation of the motor 3. The number of magnets shown in FIG. 3 is only an example, and is not limited thereto. In addition, a magnet may be provided inside a fly wheel (not shown).

As shown in FIG. 3, the angle sensor 4 includes a U-phase angle sensor 4u installed corresponding to the U of the motor 3, a V-phase angle sensor 4v installed corresponding to the V of the motor 3, and The W of the motor 3 corresponds to the W-phase angle sensor 4w installed. The angle sensors 4u, 4v, and 4w of each phase are provided on the motor 3. In this embodiment, the U-phase angle sensor 4u and the V-phase angle sensor 4v are arranged at 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 disposed at 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 phase pulse signal corresponding to the rotation position of the rotor 3r. The width of the pulse signal (or the time interval of the sensor signal) becomes narrower as the rotation speed of the motor 3 (ie, the wheel 8) becomes higher.

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

The output stage is also called an energized stage, which 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 and the target torque of the motor 3 as described later.

The control unit 10 performs ON / OFF control of the semiconductor switches Q1 to Q6 of the power conversion unit 30 using a PWM signal. In this way, the DC power supplied from the battery 2 is converted into AC power. In this embodiment, as shown in FIG. 5, the U-phase low-side switch (semiconductor switch Q2) is PWM-controlled in the output stages 6, 1, 2, and 3. The V-phase low-side switch (semiconductor switch Q4) is PWM-controlled in output stages 2, 3, 4, and 5, and the W-phase low-side switch (semiconductor switch Q6) is PWM-controlled in output stages 4, 5, 6, and 1. The level of the PWM control is determined by the energization method and the like, and is not limited to this example.

As described above, by performing ON / OFF control of the low-side switch instead of the high-side switch, it is possible to prevent the current generated by the regenerative operation of the motor 3 from flowing into the battery 2. Among them, when a regenerative current is allowed to flow into the battery 2, the high-side switch can also be ON / OFF controlled.

As shown in Figure 5, there are also times when the high-side switch becomes ON. For example, the semiconductor switch Q1, which is a U-phase high-side switch, is ON-controlled in output stages 1 and 2 at predetermined time intervals. By performing ON control of the high-end switch in this manner, it is possible to suppress heat generation of the power conversion unit 30. Among them, in order to prevent current short circuit, when the high-side switch is controlled to be ON, the corresponding (ie, the same arm) low-side switch is controlled to be OFF.

The accelerator position sensor 5 detects an operation amount of an accelerator with respect to the electric vehicle 100 (hereinafter referred to as “throttle operation amount”), and sends it to the control unit 10 as an electric signal. The amount of throttle operation is equivalent to the throttle opening of the engine car. When the user wants to accelerate, the throttle operation amount will increase, and when the user wants to decelerate, the throttle operation amount will decrease.

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

The instrument (display section) 7 is a display (for example, a liquid crystal panel) provided on the electric vehicle 100 and displays various messages. The instrument 7 is provided on a steering wheel (not shown) of the electric vehicle 100, for example. The instrument 7 displays information such as the running speed of the electric vehicle 100, the remaining amount of the battery 2, the current time, the total distance traveled, and the remaining travel distance. The remaining travel distance indicates how far the electric vehicle 100 can travel afterwards.

The charger 9 includes a power plug (not shown) and a converter circuit (not shown) that converts AC power provided by the power plug into DC power. 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 a communication network (CAN, etc.) in the electric vehicle 100, for example.

Hereinafter, the control section 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 variation calculation unit 12, a signal interval correction unit 13, a rotation speed calculation unit 14, and a motor control unit 15. The processing in each part of the control unit 10 can be realized by software (program).

The signal receiving unit 11 receives signals that come at intervals corresponding to the rotation speed of the motor 3. A plurality of signals are output from the angle sensor 4 during one rotation of the motor 3. Specifically, the signal receiving unit 11 receives the sensor signals (ie, the rising edge 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. Signal or falling edge signal). In this embodiment, the signal receiving unit 11 receives a sensor signal every time the rotor 3r of the motor 3 rotates by 60 ° at an electrical angle. The time interval at which the sensor signal arrives becomes shorter as the rotation speed of the motor 3 becomes higher.

As shown in FIG. 7, the signal receiving unit 11 confirms whether or not a sensor signal is received from the angle sensor 4 at every monitoring time interval Δtm. The monitoring time interval Δtm is, for example, a control time interval of the motor 3. The receiving of the sensor signal may also be performed by an interrupt process from the angle sensor 4.

When the electric vehicle 100 is traveling at the highest speed, the monitoring time interval Δtm is shorter than the time interval of the sensor signal received by the signal receiving unit 11, for example, 50 microseconds. Generally, when the rotation speed of the motor 3 is the maximum, the monitoring time interval Δtm is shorter than the time interval of the sensor signal received by the signal receiving section 11.

The signal interval change amount calculation unit 12 calculates a signal interval change amount which is a change amount of the signal interval (also referred to as a time between sensors). The change amount of the signal interval is shown in FIG. 7 and 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 point of the sensor signal S1 (the first signal) and the reception time point of the sensor signal S2 (the second signal). The sensor signal S1 is a sensor signal just received by the signal receiving section 11. The time point in "just received" means the closest to the current time point. The sensor signal S2 is the sensor signal received before the sensor signal S1. The second signal interval ΔT2 is a time interval between the reception time point of the sensor signal S2 and the reception time point of the sensor signal S3 (third signal). The sensor signal S3 is the sensor signal received before the sensor signal S2. The signal interval is not limited to a time interval between consecutive signals, and may also be a time interval between every other or every two signals greater than or equal to two.

In the present embodiment, the signal interval change amount calculation unit 12 calculates a difference value of the counted number as the signal interval change amount. That is, when the signal receiving section 11 does not receive the sensor signal, the signal receiving section 11 or the signal interval change amount calculating section 12 will increase the counted number. This count represents the time that has elapsed since the sensor signal was just received. The initial number of counts is 0. On the other hand, when the signal receiving unit 11 receives the sensor signal, the signal interval change calculation unit 12 counts between the sensor signal S1 and the sensor signal S2 according to the monitoring time interval Δtm. The difference between the count number ΔN (= N1-N2) between the first count number N1 and the second count number N2 after counting at the monitoring time interval Δtm between the sensor signal S2 and the sensor signal S3 as signals Interval change is calculated.

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

The signal interval correction section 13 corrects the first signal interval ΔT1 based on the signal interval change amount calculated by the signal interval change amount calculation section 12. As described later, the first signal interval ΔT1 is corrected to suppress the influence of high-frequency noise that changes earlier 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 corresponding to the amount of change in the signal interval. The weighting coefficient C is obtained by referring to the relationship diagram between the signal interval change amount and the weighting coefficient C. In the present embodiment, as shown in FIG. 8, the weighting coefficient C is obtained by referring to a relationship diagram between the difference in count number ΔN and the weighting coefficient C. The relationship diagram is stored in advance in the memory section 20 in the form of a table or a formula. When the relationship diagram is in the form of a table, the weight coefficient C is obtained by linear interpolation or the like. As shown in FIG. 8, the weighting coefficient C is set to become smaller as the absolute value of the signal interval change amount (the difference in count number ΔN) becomes larger. In addition, when the signal interval change amount is 0 (when ΔN = 0), the weight coefficient C is 1.

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

ΔTa = C × (ΔT1-ΔT2) + ΔT2… (1)

When the counted number is used as the signal interval, the counted number Na, which is the first counted number N1 after correction, is obtained by formula (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 using the formula (3).

n = 60000 / (ΔTa × Np)… (3)

Here, n is the instantaneous rotation speed of the motor 3 [rpm], ΔTa is the first signal interval [mSec] after correction, and Np is the sensor received by the signal receiving section 11 during the period when the motor 3 rotates at one electrical angle The number of signals.

When the counted number is used, the rotation speed calculation unit 14 calculates the instantaneous rotation speed of the motor 3 by using formula (4).

n = 60000 / (NaΔtm × Np)… (4)

Here, n is the instantaneous rotation speed of the motor 3 [rpm], Na is the number of counts after correction, Δtm is the monitoring time interval [mSec], and Np is the signal received by the signal receiving unit 11 during a period of one rotation of the motor 3 at an electrical angle The number of sensor signals.

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 sends control signals to the semiconductor switches Q1 to Q6 of the power conversion unit 30. Specifically, the motor control unit 15 generates a PWM signal. The PWM signal has a duty ratio calculated based on the target torque and instantaneous rotation speed of the motor 3, and is calculated based on the target torque and instantaneous rotation speed of the motor 3. The output angle is output to the power conversion unit 30. In this way, the motor 3 is controlled to generate a target torque. Among them, the PWM signal is generated in accordance with the monitoring time interval or each 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 (a) to 10 (c). The motor control unit 15 retrieves the torque map M1 by 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 to obtain a target torque. Here, as shown in FIG. 10a, the torque map M1 indicates 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 retrieves the duty cycle map M2 by using the target torque obtained from the torque map M1 and the instantaneous rotation speed calculated by the rotation speed calculation unit 14 to obtain the duty cycle. Here, the schematic diagram of the duty ratio M2 is shown in FIG. 10b, which illustrates 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.

The motor control unit 15 further retrieves the output angle map M3 by using the target torque obtained from the torque map M1 and the instantaneous rotation speed calculated by the rotation speed calculation unit 14 to obtain the output angle. Here, the output angle diagram M3 is shown in FIG. 10c, and illustrates 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.

Among them, when the control unit 10 controls the power conversion unit 30 using a plurality of energization methods (for example, a 120 ° energization method and a 180 ° energization method), the control unit 10 uses a duty cycle diagram M2 and an output angle diagram M3 corresponding to each energization mode. . That is, when the 120 ° energization method is used, the duty cycle diagram and output angle diagram for the 120 ° energization method are used to obtain the duty cycle and the output angle. The air ratio diagram and the output angle diagram are used to obtain the duty cycle and the output angle.

The PWM signal having the above-obtained duty cycle is output to the power conversion unit 30 in accordance with the above-obtained output angle, and the semiconductor switches Q1 to Q6 are ON / OFF controlled. In this way, the motor 3 is controlled to generate a required torque.

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

In this embodiment, the first signal interval ΔT1 is corrected based on the signal interval change amount (ΔT1-ΔT2) and the weight coefficient C that becomes smaller as the absolute value of the signal interval change amount becomes larger, and according to the corrected The first signal interval ΔT1 is used to calculate the instantaneous rotation speed of the motor 3. By doing so, it is possible to passivate the sensitivity of the instantaneous rotation speed for high-frequency noise for motor control. Therefore, even when the first signal interval ΔT 1 fluctuates greatly due to high-frequency noise, since the first signal interval is corrected to a correct value, it is possible to perform appropriate motor control, and the wheel as a load can be performed. 8 to drive.

In addition, according to this embodiment, since the influence of high-frequency noise can be suppressed without obtaining the average value of the signal interval as described above, the control speed of the motor 3 is not reduced.

Therefore, according to this embodiment, it is possible to appropriately drive a load without reducing the control speed of the motor 3.

The graph for obtaining the weight coefficient C is not limited to the graph shown in FIG. 8. Several modifications will be described below.

FIG. 11 is a graph showing the weight coefficient C according to the first modification. In this modification, the weighting coefficient C in the range where the count difference ΔN is greater than or equal to -α and less than or equal to + α is 1, and the weighting coefficient becomes smaller as it deviates from the range. That is, when the absolute value of the change amount of the signal interval is within a predetermined range (0 ± α), the weight coefficient C is 1, and when the absolute value of the change amount of the signal interval is outside the predetermined range, the weight coefficient C becomes smaller and smaller. By using such a weighting coefficient C, when the change amount of the signal interval is small, the first signal interval ΔT1 is used as it is to calculate the instantaneous rotation speed of the motor 3. In this way, it is possible to reflect a change in the signal interval not caused by high-frequency noise in the control of the motor 3 as it is.

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

FIG. 13 is a graph showing a weight coefficient C according to a third modification. This modification example combines the first modification example and the second modification example. That is, the weight coefficient C in the range where the count difference ΔN is equal to or greater than -α and equal to or less than + α is 1, and the decrease amount of the weight coefficient C becomes smaller as the deviation from the range becomes smaller. By using such a weighting coefficient C, it is possible to reflect a change in a signal interval not caused by high-frequency noise in the control of the motor 3 as it is, and it is possible to sufficiently apply even when a strong external force is applied to a load. Suppresses signal interval variation.

> Electric Vehicle Control Method>

An example of the electric vehicle control method according to the present embodiment will be described below with reference to the flowchart of FIG. 14. Among them, the count number is initialized in advance.

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

On the other hand, when a sensor signal is received (S12: Yes), the signal interval change amount calculation unit 12 calculates a difference ΔN between the count number N1 this time and the previous count number N2 ( Step S14). Here, the count number N1 this time is the count number after counting between the sensor signal S1 and the sensor signal S2, and the previous count number N2 is between the sensor signal S2 and the sensor signal S3. The number of counts after the interval count.

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

Then, the signal interval correction unit 13 obtains a weighting coefficient C corresponding to the count number difference ΔN calculated in step S14 (step S16). Then, the signal interval correction unit 13 corrects the counted number N1 this time (step S17). Specifically, the formula (2) is used to calculate the corrected first count number N1 (that is, the count number Na).

Next, the rotation speed calculation unit 14 calculates the instantaneous rotation speed of the motor 3 based on the counted number Na calculated in step S17 (step S18). Specifically, the instantaneous rotation speed of the motor 3 is calculated using the formula (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) to 10 (c), a PWM signal for acquiring a predetermined torque is generated and output to the power conversion unit 30.

Among them, although the counted number is used in the above-mentioned processing flow, the time interval of receiving the sensor signal may also be used to calculate the change amount of the signal interval. In addition, when the sensor signal is not received (S12: No), the operating amount of the accelerator just now and the instantaneous rotation speed calculated last time can be used to obtain the duty cycle from the duty cycle diagram M2. Accordingly, the PWM signal transmitted to the power conversion unit 30 is updated.

At least a part of the electric vehicle control device 1 (control unit 10) described in the above embodiment may be configured by hardware or software. When the software is configured, a program that realizes at least a part of the functions of the control unit 10 may be stored in a storage medium such as a floppy disk and a CD-ROM, and read by a computer and then run. The storage medium is not limited to a removable magnetic disk, an optical disk, and the like, and may be a fixed storage medium such as a hard disk device and a storage device.

The 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. The program may be further distributed in a state of being encrypted, modulated, and compressed through a limited line such as the Internet and a wireless line, or stored in a storage medium.

Based on the above description, although a person having ordinary knowledge in the art may think of additional effects and various modifications of the present invention, the embodiments of the present invention are not limited to the various embodiments described above. The constituent elements according to different embodiments may be appropriately combined. Various additions, changes, and partial deletions can be made without departing from the contents specified in the scope of the patent application and the concept and gist of the present invention derived from its equivalent.

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‧‧‧ Throttle position sensor

6‧‧‧ auxiliary switch

7‧‧‧ instrument

8‧‧‧ Wheel

9‧‧‧ Charger

10‧‧‧Control Department

11‧‧‧Signal receiving department

12‧‧‧Signal interval change calculation unit

13‧‧‧Signal interval correction section

14‧‧‧Rotation speed calculation department

15‧‧‧Motor Control Department

20‧‧‧Memory Department

30‧‧‧Power Conversion Department

100‧‧‧ electric vehicles

M1‧‧‧ torque diagram

M2‧‧‧ Duty Cycle

M3‧‧‧ output angle diagram

Q1, Q2, Q3, Q4, Q5, Q6‧‧‧Semiconductor switches

S1, S2, S3‧‧‧ sensor signals

FIG. 1 is a schematic configuration diagram of an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a power conversion unit and a motor.

FIG. 3 is a schematic diagram of a magnet and an angle sensor provided on a rotor of a motor.

Fig. 4 is a schematic diagram showing the relationship between the rotor angle and the output of the angle sensor.

FIG. 5 is a timing chart for explaining PWM control according to the embodiment.

Fig. 6 is a block diagram of functions of a control unit of the electric vehicle control device.

FIG. 7 is an explanatory diagram for explaining the relationship between the sensor signal and the number of counts.

FIG. 8 is a graph for obtaining a weight coefficient according to the embodiment.

FIG. 9 is a schematic diagram for explaining a calculation process of a duty cycle and an output angle of a PWM signal.

Fig. 10a shows the structure of the torque diagram, Fig. 10b shows the structure of the duty cycle diagram, and Fig. 10c shows the structure of the output angle diagram.

FIG. 11 is a graph for obtaining a weight coefficient according to the first modification.

FIG. 12 is a graph for obtaining a weight coefficient according to a second modification.

FIG. 13 is a graph for obtaining a weight coefficient according to a third modification.

FIG. 14 is a flowchart for explaining an example of an electric vehicle control method according to the embodiment.

Claims (15)

A driving device includes: The signal receiving unit receives signals that arrive at intervals corresponding to the rotation speed of the motor driving the load; The signal interval change calculation unit calculates a signal interval change that is the difference between the first signal interval and the second signal interval. The first signal interval is the reception time of the first signal just received by the signal receiving unit. The signal interval between the reception point of the second signal received earlier than the first signal and the reception time point of the second signal received earlier than the first signal, and the second signal interval is the reception time point of the second signal and received before the second signal The signal interval between the reception points of the third signal; A signal interval correction unit that corrects the first signal interval according to the signal interval change amount; The rotation speed calculation unit calculates the instantaneous rotation speed of the motor based on the corrected first signal interval; and The motor control unit controls the motor based on the calculated instantaneous rotation speed. The driving device according to item 1 of the scope of patent application, wherein the signal interval correction unit obtains a weight coefficient corresponding to the signal interval change amount, and multiplies the weight coefficient by the signal interval change amount, and The signal interval change amount multiplied by the weight coefficient is added to the second signal interval to correct the first signal interval. The driving device according to item 2 of the scope of patent application, wherein the weight coefficient becomes smaller as the absolute value of the signal interval variation becomes larger. The driving device according to item 3 of the patent application range, wherein the reduction amount of the weighting coefficient decreases as the absolute value of the change amount of the signal interval becomes larger and smaller. The driving device according to item 3 of the scope of patent application, wherein the weight coefficient value is 1 when the signal interval variation is 0. The driving device according to item 2 of the patent application range, wherein when the absolute value of the change amount of the signal interval is within the specified range, the weight coefficient is 1, and when the absolute value of the change amount of the signal interval is outside the specified range , The weight coefficient becomes smaller as the absolute value becomes larger. The driving device according to item 1 of the patent application scope, wherein the second signal is a signal received before the first signal and the third signal is a signal received before the second signal In the case of a signal, the instantaneous rotational speed is calculated by the rotational speed calculation section by the following formula: n = 60000 / (ΔTa × Np) In the above formula, n represents the instantaneous rotation speed (rpm), ΔTa represents the first signal interval (mSec) after correction, and Np represents the dry signal received by the signal receiving unit during a period of one revolution of the motor. quantity. The driving device according to item 1 of the scope of patent application, wherein in the case where the signal receiving section receives the first signal, the signal interval variation calculating section will calculate between the first signal and the second signal according to The difference in count between the first count after counting at the monitoring interval and the second count after counting at the monitoring interval between the second signal and the third signal is taken as the signal interval change The signal interval correction unit obtains a weighting coefficient corresponding to the difference between the counted quantities, multiplies the weighted coefficient with the difference between the counted quantities, and multiplies the counted quantity by the weighted coefficient. The difference is added to the second count number to correct the first count number. The driving device according to item 8 of the patent application scope, wherein the monitoring time interval is shorter than the time interval of the signals received by the signal receiving unit when the rotation speed of the motor is at a maximum. The driving device according to item 8 of the scope of patent application, wherein the signal interval variation calculation unit resets the first count quantity after calculating the difference in the count quantity. The driving device according to item 1 of the patent application range, wherein the signal received by the signal receiving section is a rising edge signal or a falling edge signal of a pulse signal output from a rotary position sensor provided at the motor. An electric vehicle includes the device described in item 1 of the scope of patent application, and the load is a driving device for a wheel of the electric vehicle. The electric vehicle according to item 12 of the scope of patent application, wherein the wheel and the motor are mechanically connected without passing through a clutch. A driving method including: A step of the signal receiving unit receiving a signal that arrives at an interval corresponding to the rotation speed of the motor driving the load; The signal interval change amount calculating unit calculates a signal interval change amount as a difference between the first signal interval and the second signal interval. The first signal interval is a reception of the first signal just received by the signal receiving unit. The signal interval between the time point and the reception time point of the second signal received earlier than the first signal, and the second signal interval is the reception time point of the second signal and the second signal received earlier than the second signal. The signal interval between the receiving time points of the third signal; A step of correcting the first signal interval by the signal interval correction unit according to the change amount of the signal interval; A step of the rotation speed calculating unit calculating the instantaneous rotation speed of the motor based on the corrected first signal interval; and A step of the motor control unit controlling the motor based on the calculated instantaneous rotation speed. A driver, where: Make the computer execute: A step of the signal receiving unit receiving a signal that arrives at an interval corresponding to the rotation speed of the motor driving the load; The signal interval change amount calculating unit calculates a signal interval change amount as a difference between the first signal interval and the second signal interval. The first signal interval is a reception of the first signal just received by the signal receiving unit. The signal interval between the time point and the reception time point of the second signal received earlier than the first signal, and the second signal interval is the reception time point of the second signal and the second signal received earlier than the second signal. The signal interval between the receiving time points of the third signal; A step of correcting the first signal interval by the signal interval correction unit according to the change amount of the signal interval; A step of the rotation speed calculating unit calculating the instantaneous rotation speed of the motor based on the corrected first signal interval; and A step of the motor control unit controlling the motor based on the calculated instantaneous rotation speed.