JP2019154089A - Motor drive controller and autonomous travel device - Google Patents

Abstract

To reduce time when regenerative current is made to flow in a regenerative resistor, to reduce interruption of travel even in a long downhill and to expand continuous travel time.SOLUTION: A motor drive controller comprises: a motor; a motor drive section for generating a drive signal for driving the motor and outputting it to the motor; a regenerative resistor for consuming regenerative power generated during regeneration operation; a field current PI control section which inputs input voltage of the motor drive section and outputs a field correction current value for controlling field current which is a field component of the drive signal, which does not contribute to torque of the motor, on the basis of a change of the input voltage; and a drive current control section for correcting torque current that is a torque component of the drive signal, which contributes to the torque of the motor, and the field current by using the field correction current value. The drive current control section corrects the field current so that a part of the regenerative current generated during regeneration operation can be consumed by the motor, and the motor drive section generates the drive signal corresponding to the corrected field current.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a motor drive control device and an autonomous traveling device, and in particular, a motor drive control device for autonomously traveling an autonomous traveling device by rotating a motor with electric power from a rechargeable battery, and an autonomous traveling device equipped with the motor drive control device. About.

In vehicles that have a rechargeable battery, such as an electric vehicle, and run autonomously by rotating a motor driven by the power from the rechargeable battery, regenerative power is generated when braking is applied, such as when traveling downhill, The rechargeable battery is charged using this regenerative power.
In addition, a regenerative power control device is provided to control the regenerative current flowing in the rechargeable battery and consume excess regenerative power to prevent overcharge of the rechargeable battery.

For example, when the power supply voltage of the rechargeable battery is monitored and a power supply voltage that exceeds a specified voltage value is detected, current is passed through the regenerative resistor provided in the regenerative power control device, and excess regenerative power is consumed by the regenerative resistor. Has been done.
Further, in Patent Document 1, in response to an increase in the voltage of the battery, charging of the battery, a decrease in the regeneration efficiency of the motor for driving the vehicle, and a regenerative current caused by flowing a regenerative current through the bypass circuit are stepwise. A regenerative braking device is described that prevents overcharging of a battery by controlling the consumption of the regenerative current in the order of consumption, regenerative current consumption by flowing a regenerative current through a regenerative resistor connected in parallel with the battery. .

JP-A-8-154304

  However, as in the past, by supplying regenerative current to the regenerative resistor, excess regenerative power can be consumed by the regenerative resistor, but when the regenerative current flows to the regenerative resistor, the regenerative current is converted to heat at the regenerative resistor. As a result, the regenerative resistor generates heat.

Especially when traveling downhill at high speed or when traveling downhill continuously for a long time, a regenerative current flows continuously to the regenerative resistor, which may cause the regenerative resistor to become an unexpectedly high temperature. is there. When the high temperature state of the regenerative resistor continues, the regenerative resistor may burn out.
Further, in order to avoid the regenerative resistor from being burned out, it is necessary to cool the regenerative resistor to a predetermined temperature. For example, it is necessary to temporarily stop traveling.
In this way, when a regenerative current is passed through a regenerative resistor and the regenerative current is converted into heat and excess regenerative power is consumed, the travel is temporarily interrupted when there are many downhills in the travel route of the autonomous vehicle. As a result, the autonomous driving assumed in advance may not be continued.

  Therefore, the present invention has been made in consideration of the above circumstances, and reduces the time for which the regenerative current flows through the regenerative resistor, thereby reducing the interruption of traveling even on long downhills, and the like. An object of the present invention is to provide a motor drive control device and an autonomous traveling device capable of extending traveling time and continuing autonomous traveling as much as possible.

  The present invention relates to a motor, a motor drive unit that generates a drive signal for driving the motor and outputs the drive signal, a regenerative resistor that consumes regenerative power generated during a regenerative operation, and an input voltage of the motor drive unit And a field current PI control unit that outputs a field correction current value for controlling a field current that is a field component of the drive signal that does not contribute to the torque of the motor based on a change in the input voltage And using the field correction current value, a torque current that is a torque component of the drive signal that contributes to the torque of the motor and a field current that is a field component of the drive signal that does not contribute to the torque of the motor. A drive current control unit that corrects, the drive current control unit corrects the field current so that a part of the regenerative power generated during the regenerative operation can be consumed by the motor, and the motor drive unit But There is provided a motor drive control device and generates the driving signal corresponding to the corrected field current.

Further, when the input voltage of the motor drive unit is increased during the regeneration operation, the field current PI control unit increases the field correction current value in response to the increase of the input voltage, The drive current control unit increases the regenerative power consumed by the motor by correcting the field current so that the field current increases in response to the increased field correction current value. Features.
According to this, since the regenerative power consumed by the motor is increased by correcting the field current so as to increase the field current in response to the increase of the input voltage, the regenerative current is passed through the regenerative resistor. The time can be reduced to prevent the temperature of the regenerative resistor from rising, and the autonomous traveling device provided with the motor drive control device can continue autonomous traveling for a long time.

Further, the storage device further includes a storage unit that stores a reference voltage, and the field current PI control unit further inputs the reference voltage, based on a difference between the input voltage of the input motor driving unit and the reference voltage. A target value generating unit for generating a field current target value and a limiter that sets an upper limit value of the field current target value, and when the generated field current target value is equal to or higher than the upper limit value. The upper limit value is output as the field correction current value, and when the generated field current target value is smaller than the upper limit value, the field current target value is set as the field correction current value. Is output as
According to this, since the upper limit value is set for the field current target value, it is possible to prevent a sudden increase in the field current and to prevent the rotational operation of the motor from falling into an unstable circulation, and to stabilize the field current. Driving can be ensured.

The motor further includes an electrical angle estimation unit that generates a rotation speed of the motor, the rotation speed is input to the field current PI control unit, and the limiter corresponds to the input rotation speed, When the maximum value of the field correction current value is set to a value lower than the upper limit value of the field current target value, and the rotation speed is increased to a predetermined value or more, the field current PI control unit The maximum value of the field correction current value is decreased as the rotational speed increases.
According to this, the maximum value of the field correction current value is set to a value lower than the upper limit value of the field current target value corresponding to the rotation speed, and as the rotation speed increases, the field correction current value Since the maximum value is reduced, an increase in the back electromotive force of the motor is suppressed, autonomous running can be made more stable, and continuous running for a longer time becomes possible.

The apparatus further includes a first temperature measurement unit that measures the temperature of the motor drive unit, the measured temperature of the motor drive unit is input to the field current PI control unit, and the limiter is input. When the maximum value of the field correction current value is set to a value lower than the upper limit value of the field current target value corresponding to the temperature, and the input temperature rises above a predetermined value, the field correction current value The magnetic current PI control unit decreases the maximum value of the field correction current value as the input temperature increases.
According to this, since the maximum value of the field correction current value is decreased from the upper limit value of the field current target value as the temperature of the motor driving unit increases, the increase in the field current is suppressed, and the motor driving unit The temperature of the motor is controlled so as not to exceed the rated maximum temperature value, so that the semiconductor components of the motor drive unit are prevented from being damaged, and more stable autonomous traveling for a long time becomes possible.

  Further, the apparatus further comprises a second temperature measuring unit that measures the temperature of the regenerative resistor, the measured temperature of the regenerative resistor is input to the field current PI control unit, and the field current PI control unit includes: In response to the input temperature of the regenerative resistor, the maximum value of the field correction current value is changed, and the drive current control unit outputs the field correction current value output from the field current PI control unit. By adjusting the field current according to the above, the consumption of the regenerative power by the regenerative resistor and the consumption of the regenerative power in the motor generated by increasing the field current are adjusted. And

  Further, the apparatus further comprises a second temperature measuring unit that measures the temperature of the regenerative resistor, the measured temperature of the regenerative resistor is input to the field current PI control unit, and the field current PI control unit includes: The maximum value of the field correction current value is changed corresponding to the input temperature of the motor driving unit and the temperature of the regenerative resistor, and the driving current control unit is output from the field current PI control unit By correcting the field current in accordance with the field correction current value, consumption of regenerative power by the regenerative resistor, and consumption of regenerative power in the motor generated by increasing the field current, It is characterized by adjusting.

  The present invention is also an autonomous traveling device including a vehicle body, a drive member that causes the vehicle body to travel, and a motor drive control device that controls the drive member, wherein the motor drive control device is described above. The present invention provides an autonomous traveling device that is any one of motor drive control devices.

  Further, the present invention contributes to the torque of the motor based on the change in the input voltage of the motor drive unit that generates the drive signal for driving the motor by consuming the regenerative power generated during the regenerative operation by the regenerative resistor. Output a field correction current value for controlling a field current that is a field component of the drive signal, and use the output field correction current value to output a drive signal that contributes to the torque of the motor. A torque current that is a torque component and a field current that is a field component of a drive signal that does not contribute to the torque of the motor are corrected, and the correction of the field current is a part of the regenerative power generated during the regenerative operation. The correction to enable consumption by the motor. When the input voltage of the motor drive unit increases during the regenerative operation, the field correction current value is increased in response to the increase of the input voltage. , By correcting the field current so that the field current increases corresponding to the increased field correction current value, the regenerative power consumed by the motor is increased, and the corrected torque current The motor drive method of the motor drive control apparatus is characterized in that a drive signal corresponding to the corrected field current is generated and the motor is driven by the drive signal.

  According to the present invention, the motor drive unit that generates a drive signal for driving the motor and outputs the drive signal to the motor, and the input voltage of the motor drive unit are input, and the motor torque is not contributed based on the change in the input voltage. A field current PI controller that outputs a field correction current value for controlling a field current that is a field component of the drive signal, and a drive that contributes to the torque of the motor using the field correction current value A torque current that is a torque component of the signal, and a drive current control unit that corrects a field current that is a field component of the drive signal that does not contribute to the torque of the motor. The field current is corrected so that a part of the electric power can be consumed by the motor, and the motor drive unit generates a drive signal corresponding to the corrected field current. Decrease and long down In such hill reduces the disrupting travel, it is possible to expand the continuous running time, the autonomous travel of the autonomous traveling device provided with a motor drive control device, it is possible to possible long-lasting.

It is a block diagram of a 1st embodiment of composition about a motor drive control device of an autonomous running device of this invention. It is a block diagram of the first embodiment of the motor drive unit of the present invention. It is a block diagram of the first embodiment of the field current PI control unit of the present invention. It is one Example of the characteristic graph in the limiter of the field current PI control part of this invention. It is a schematic explanatory drawing of the motor drive operation | movement at the time of the input voltage rise of a motor drive part. It is a block diagram of 2nd Embodiment of the structure regarding the motor drive control apparatus of the autonomous running apparatus of this invention. It is a block diagram of the second embodiment of the field current PI control unit of the present invention. It is one Example of the characteristic graph which shows the relationship between the rotational speed in the limiter of the field current PI control part of this invention, and the maximum value of a field correction current. It is a block diagram of 3rd Embodiment of the structure regarding the motor drive control apparatus of the autonomous running apparatus of this invention. It is a block diagram of the third embodiment of the motor drive unit of the present invention. It is a block diagram of the third embodiment of the field current PI control unit of the present invention. It is one Example of the characteristic graph which shows the relationship between the temperature of the inverter in the limiter of the field current PI control part of this invention, and the maximum value of a field correction current. It is a structure block diagram of 4th Embodiment in the motor drive part of this invention. It is a schematic explanatory drawing which shows a response | compatibility with the temperature of the motor drive part of this invention, and regenerative power consumption. It is a schematic explanatory drawing of one Example which shows a response | compatibility with the driving | running route of the autonomous traveling apparatus of this invention, and regenerative electric power consumption. It is a flowchart of one Example of the motor drive control process in the autonomous running apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of one Example of the autonomous traveling apparatus of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by description of the following examples.
The autonomous traveling device of the present invention includes a vehicle body, a drive member (wheel) for traveling the vehicle body, and a motor drive control device that controls the drive member, and is autonomous while avoiding an obstacle based on predetermined route information. It is a vehicle which has a function to move automatically.
The motor drive control device includes a rechargeable battery (hereinafter also referred to as a battery), and drives a motor that rotates a wheel using electric power supplied from the rechargeable battery.
The autonomous traveling device may include various functions such as a transportation function, a monitoring function, a cleaning function, a guidance function, and a notification function in addition to the moving function.

<Configuration of autonomous traveling device>
In FIG. 17, the external view of one Example of the autonomous running apparatus of this invention is shown.
In the external view of FIG. 17, the autonomous mobile device 1 (hereinafter also referred to as a vehicle) mainly includes a vehicle body 4, four wheels (front wheels 5 and rear wheels 6), a monitoring unit 2, a control unit 3, A battery is provided.
The monitoring unit 2 is a part having a function of confirming a moving region and a road surface state and a function of monitoring a monitoring target. For example, the monitoring unit 2 confirms the state of a camera (imaging device) 7 or a moving front space (not shown). It is comprised from a distance detection apparatus, the positional information acquisition apparatus etc. which acquire the information of the present position which drive | works.
The control unit 3 is a part that executes a traveling function, a monitoring function, and the like of the autonomous traveling device, and includes, for example, a control device, a motor, a motor drive control device, a communication device, and a storage device that are not shown.
As the rechargeable battery, for example, a lithium ion battery or the like is used, and the rechargeable battery is placed at the lower part of the center position of the vehicle body.

The autonomous traveling device 1 of the present invention self-travels while confirming the front state of the traveling direction of the vehicle body using a camera, a distance detection device, or the like. For example, when it is detected that there are obstacles, steps, etc. ahead, the course is changed by performing operations such as rest, rotation, backward movement, and forward movement in order to prevent collision with the obstacles. When an obstacle is recognized or contact is detected, a predetermined function such as a stop operation of the vehicle body is executed.
Also, in order to prevent the input voltage of the motor drive device from rising due to regenerative power during traveling and exceeding the withstand voltage of the electronic component and damaging the electronic component, regenerative power generated during regenerative operation is consumed by the regenerative resistor. When the regenerative resistance becomes equal to or higher than a predetermined temperature, the traveling is stopped.

However, as will be described later, the regenerative power is controlled so that the motor itself consumes the regenerative power and the autonomous running can be continued as much as possible so that the regenerative resistance does not exceed a predetermined temperature.
Further, when the remaining capacity of the rechargeable battery is decreasing, the battery returns to a predetermined position or stops traveling.
In the present invention, among the functions of the autonomous mobile device, the motor drive control function is particularly characteristic. Therefore, in the following embodiments, the motor drive control mainly related to the motor drive and regenerative power control of the autonomous mobile device. The configuration, function, and operation of the apparatus will be described.

(First embodiment of autonomous traveling device)
<Configuration of motor drive control device of autonomous traveling device>
FIG. 1 shows a block diagram of a first embodiment of a configuration relating to a motor drive control device of an autonomous traveling device of the present invention.
1, the motor drive control device of the autonomous traveling device 1 of the present invention mainly includes a speed PI control unit 11, a current PI control unit 12, an inverse Park conversion unit 13, a three-phase signal generation unit 14, a motor drive unit 15, A current acquisition unit 16, a Clark conversion unit 17, a Park conversion unit 18, an electrical angle estimation unit 19, a motor 21, a rotation speed detection unit 22, a power supply unit 23, a field current PI control unit 24, and an adder 25 are provided.
As will be described later, the current PI control unit 12, the inverse Park conversion unit 13, the three-phase signal generation unit 14, the current acquisition unit 16, the Clark conversion unit 17, and the Park conversion unit 18 constitute a drive current control unit 20.

The control unit 10 is a part that controls the overall operation of the autonomous mobile device 1 and also controls the operation of the motor drive control device.
The motor 21 is a target controlled by the motor drive control device, and is a three-phase brushless DC motor.
In the motor drive control device of the present invention, the rotation of the motor is controlled using vector control.
Although not shown in FIG. 1, a regenerative resistor that consumes regenerative power generated during the regenerative operation is provided.

The control unit 10 of the autonomous traveling device 1 is a part that controls the operation of each component of the motor drive control device such as the power supply unit 23, and is a micro that mainly includes a CPU, ROM, RAM, I / O controller, timer, and the like. Realized by computer.
The CPU organically operates various hardware based on a control program stored in advance in a ROM or the like, and executes the traveling function, the regeneration control function, and the like of the present invention.

The control unit 10 includes a storage unit 10a. As the storage unit, a semiconductor memory such as a ROM, a RAM, or a flash memory, or a storage device such as a hard disk HDD or an SSD is used.
In the present invention, in particular, reference values such as a reference voltage Vddref and a target rotational speed ωref described later are stored in advance in the storage unit 10a such as a ROM.
The control unit 10 reads out the stored reference voltage and the like from the storage unit and supplies the reference voltage to the motor drive control device, so that the motor drive control device drives the motor 21 using the reference voltage and the like.

The speed PI control unit 11 is a part that generates information for adjusting the rotation speed of the motor.
In particular, the current rotation speed ω of the motor and the target rotation speed ωref given from the control unit 10 are used as input data, and the rotation of the motor is controlled so that the rotation speed ω matches the target rotation speed ωref. Two-phase reference current information (Iqref, Idref) is output.
The motor includes a rotor (rotor) in which permanent magnets are embedded, and three electromagnets are arranged at predetermined intervals in a space near the rotor.
The rotor included in the motor is rotated by the generated magnetic field by changing the current flowing through the three electromagnets, but the force to rotate the rotor is decomposed into two orthogonal components (torque component and field component) Is done.

The two-phase reference current information is current information corresponding to these two components, the reference current corresponding to the torque component is called the torque target current Iqref, and the reference current corresponding to the field component is the field target current. Called Idref.
That is, the speed PI control unit 11 generates a torque target current Iqref and a field target current Idref from the input rotational speed ω and the target rotational speed ωref.

The current PI control unit 12 is a part that generates information for correcting the current for rotating the motor.
Here, the above-described two-phase reference current information (torque target current Iqref, field target current Idref) and the two-phase monitor current (Iq, Id) converted from the current value for driving the motor are used. As input data, PI control is performed so that the reference current information matches the monitor current, and correction information is output.

The input two-phase monitor current is the torque current Iq corresponding to the torque component and the field current Id corresponding to the field component. The torque target current Iqref, the torque current Iq, and the field target current Idref PI control is performed so that the field currents Id match each other.
Since the current increases and decreases in proportion to the voltage, the voltage is controlled to increase and decrease the current. Therefore, the correction information output from the current PI control unit is a voltage value (correction voltage).

Of the two-phase correction information that is output, the correction voltage corresponding to the torque component is called the torque correction voltage Vq, and the correction voltage corresponding to the field component is called the field correction voltage Vd.
The two-phase correction voltages (Vq, Vd) are components in the tangential direction and normal direction of the rotor, and become rotational coordinates because the rotor is rotating.
The inverse Park conversion unit 13 converts the correction voltage (Vq, Vd) of the rotation coordinate into the fixed coordinate (Vα, Vβ) by performing vector calculation using the rotation angle θel of the rotor given from the electrical angle estimation unit 19. To do.

The three-phase signal generation unit 14 is a part that generates a three-phase control voltage (hereinafter referred to as a three-phase control signal) from the two-phase correction voltages (Vα, Vβ) after conversion into fixed coordinates.
A three-phase control in a state in which a predetermined space vector conversion process is performed on the two-phase correction voltages (Vα, Vβ) after conversion into fixed coordinates by the inverse Park conversion unit 13 and can be input to the motor drive unit 15. A voltage (three-phase control signal) is generated.
The three-phase signal generator 14 is also called an SVPWM generator (Space Vector Pulse Width Modulation).

The three-phase control signals to be generated are six signals (u, v, w, x, y, z) respectively given to six transistors included in the motor drive unit 15 described later.
The three-phase control signals x, y, and z are generated by inverting the three-phase control signals u, v, and w, respectively.

The motor drive unit 15 is a part that generates a drive signal for driving the motor 21 and outputs the drive signal to the motor 21.
In particular, when the motor 21 is a three-phase brushless DC motor, it is a part that gives a three-phase drive signal for driving the motor 21 to the motor 21 and is also called an inverter.
Here, six three-phase control signals (u, v, w, x, y, z) output from the three-phase signal generator 14 are input, and a three-phase drive signal (U, V) for driving the motor 21 is input. V, W) is output.
As will be described later, the motor drive unit 15 is an electronic circuit mainly including three sets of drive circuits each composed of upper and lower transistors. From the three lines drawn from between the upper and lower transistors, The three-phase drive signals (U, V, W) are supplied to the motor 21, respectively.
The rotor included in the motor 21 is rotated by giving the three-phase motor 21 an AC signal of a sine wave three-phase drive signal (U, V, W) whose phase is shifted by 120 degrees.

In addition, current information (measurement current) obtained by measuring the current values of the drive currents flowing through the three lines that output the three-phase drive signals (U, V, W) is output to the current acquisition unit 16.
The output measurement currents (Iu, Iv, Iw) are three-phase drive currents measured for every three lines, and are called three-phase measurement currents.

The current acquisition unit 16 is a part that acquires the three-phase measurement currents (Iu, Iv, Iw) output from the motor drive unit 15 and converts them into two-phase measurement currents (Ia, Ib).
Since Iu + Iv + Iw = 0 from the characteristics of the three-phase alternating current, if data for two phases can be acquired in Iu, Iv, and Iw, data for all phases is acquired. Iu, Iv, Iw changes depending on the rotation angle, and the accuracy of each phase data is converted, so two-phase data with high accuracy is acquired, and based on this, data for two phases (Ia, Ib) ).
The two-phase measurement currents (Ia, Ib) are given to the Clarke conversion unit 17.

The Clarke conversion unit 17 converts the two-phase measurement current (Ia, Ib) output from the current acquisition unit 16 into a two-phase monitor current (Iα, Iβ) in the same coordinate system as (Vα, Vβ). .
The (Iα, Iβ) generated here is a current value with fixed coordinates.

The Park conversion unit 18 is a part that converts a two-phase monitor current (Iα, Iβ) expressed in fixed coordinates into rotation coordinates by performing vector calculation.
Here, the current component in the tangential direction of the rotor is referred to as torque current Iq, and the current component in the normal direction is referred to as field current Id.
As described above, the torque current Iq and the field current Id after being converted into the rotation coordinates are given to the current PI control unit 12.

The rotational speed detection unit 22 is a part that detects the rotational speed of the motor 21, and uses, for example, a Hall IC.
Since the Hall IC can detect the N pole and S pole of the magnet, the direction of the rotor can be detected by arranging it at an angle of 120 ° around the rotor. For example, a three-phase Hall IC output signal (ω1, ω2, ω3) is obtained by outputting a digital signal that becomes 1 when the N pole is detected from the Hall IC and becomes 0 when the S pole is detected.

The electrical angle estimation unit 19 is a part that mainly generates the rotational speed ω of the motor.
Here, the rotation angle θel of the rotor and the rotation speed ω of the motor are generated from the Hall IC output signals (ω1, ω2, ω3) given from the rotation speed detection unit 22. For example, the rotational speed ω can be calculated by measuring the inversion period of (ω1, ω2, ω3). In addition, there are 6 patterns except for (0, 0, 0) (1, 1, 1) in 0, 1 pattern of (ω1, ω2, ω3). You can get a corner. Since the rotation angle can be estimated from the rotation speed ω when rotating at a constant speed, the rotation angle with 60 ° accuracy obtained directly is interpolated to calculate a more accurate rotation angle.
The rotation angle θel of the rotor is given to the inverse Park conversion unit 13 and the Park conversion unit 16.
The rotational speed ω is given to the speed PI control unit 11.

The power supply unit 23 is a power source that operates the autonomous traveling device, and a rechargeable battery is used for the autonomous traveling device to self-propel. The rechargeable battery supplies a predetermined power supply voltage to a member that operates by electricity of the autonomous mobile device.
As the rechargeable battery 23, a lead storage battery or an air battery may be used in addition to the lithium ion battery.
The DC power supplied from the rechargeable battery is supplied to a control unit, a motor drive control device, and other members that operate by electricity such as a camera.
The rechargeable battery is a DC power supply, and for example, a DC voltage of the power supply voltage Vdd is given to the motor drive unit 15, the field current PI control unit 24, and the like.
The power supply voltage Vdd is not uniquely determined, but for example, 24V or 48V is often used.
Further, as shown in FIG. 2 to be described later, the power supply unit 23 is configured in parallel with the rechargeable battery, a voltage detection unit (voltage sensor) 63 that measures the input voltage Vdd of the motor drive unit, and a regenerative power consuming regenerative power. A resistor 62 and a transistor 61 connected in series to the regenerative resistor 62 are connected.

The field current PI control unit 24 is a part that adjusts the field target current Idref input to the current PI control unit 12 in response to a change in the input voltage Vdd of the motor drive unit.
In the present invention, in particular, the field correction current for inputting the input voltage of the motor drive unit and controlling the field current which is the field component of the drive signal that does not contribute to the torque of the motor based on the change of the input voltage. Value is output and the field target current Idref is adjusted.
Hereinafter, the output field correction current value is also referred to as a field correction current ΔIdref.

As will be described later, an excessive increase in the input voltage Vdd of the motor drive unit based on the regenerative operation is not preferable because it may cause a large amount of heat generation in the regenerative resistance and may require the suspension of traveling.
When using a SPM (Surface Permanent Magnet) type brushless DC motor, a two-phase monitor current (torque current Iq, field field) obtained from the three-phase measurement current output from the motor drive unit 15 that drives the motor is used. Of the current Id), the torque current Iq contributes to the rotational torque of the motor, and the field current Id, which is a field component, does not contribute to the rotational torque.
Therefore, in principle, even if the field current Id is increased, the rotational speed of the motor does not change. Increase / decrease in the field current Id is controlled by increase / decrease in the field target current Idref input to the current PI control unit 12.

Further, when the field current Id is increased, the drive current flowing through the motor drive unit 15 that drives the motor is increased.
Therefore, in the present invention, when the input voltage Vdd of the motor driving unit rises to a predetermined reference voltage or higher, the regenerative power is not consumed only by the regenerative resistor, but the field component that does not directly contribute to the rotation of the motor. By increasing the field target current and increasing the drive current flowing to the motor, control is performed so that the motor itself consumes regenerative power and suppresses the increase in the input voltage Vdd of the motor drive unit.

The field current PI control unit 24 uses the input voltage Vdd of the motor driving unit and the reference voltage Vddref supplied from the control unit 10 as input data, and outputs a field correction current ΔIdref.
The field correction current ΔIdref is a current value for adjusting the field target current Idref output from the speed PI control unit 11 and is given to the adder 25.
The reference voltage Vddref is a voltage value that serves as a guideline that the input voltage Vdd of the motor driving unit rises and that the field target current Idref needs to be adjusted, and is stored in advance in a storage device such as a ROM.
The adder 25 adds the field correction current ΔIdref and the field target current Idref, and gives ΔIdref + Idref to the current PI control unit 12.

The field current PI control unit 24 compares the input voltage Vdd of the motor driving unit and the reference voltage Vddref to be inputted, performs a predetermined calculation, and the input voltage Vdd of the motor driving unit exceeds the reference voltage Vddref. In the case (Vdd> Vddref), the field correction current ΔIdref corresponding to the excess amount (Vdd−Vddref) is calculated.
If this excess amount (Vdd−Vddref) increases, the field correction current ΔIdref also increases.

When the field correction current ΔIdref increases, the output value (ΔIdref + Idref) of the adder 25 input to the current PI control unit 12 increases, and the drive current of the field component given to the motor increases, so that the motor itself Regenerative power is consumed.
As the regenerative power is consumed by the motor itself, the increase in the input voltage Vdd of the motor drive unit is suppressed, so the regenerative power consumption due to the regenerative resistor is suppressed and the energization time to the regenerative resistor is reduced, so The rise in the temperature is suppressed.
In particular, in situations where regenerative operations occur continuously while traveling on a long downhill, it is possible to prevent the situation where traveling must be interrupted by suppressing the increase in the temperature of the regenerative resistance. In addition, the continuous travel time of the autonomous traveling device can be extended.
The block of the internal configuration of the field current PI control unit 24 will be described later.

In the first embodiment, for example, when the standard power supply voltage Vdd of the rechargeable battery is 50 volts and the reference voltage Vddref is preset to 60 volts, the current input voltage of the motor drive unit Until Vdd reaches 60 volts, only the regenerative power consumption by the regenerative resistor may be used, and the regenerative power consumption by the increase of the field current Id may not be used.
On the other hand, when the current input voltage Vdd of the motor drive unit exceeds the reference voltage Vddref (Vdd> Vddref), the field correction current ΔIdref is output and the regenerative power consumption due to the increase of the field current Id (the motor itself) (Consumption of regenerative electric power in).

<Outline of motor drive control processing>
The configuration block of the motor drive control device has been described above. The motor drive control device is a motor drive control module mainly composed of one or a plurality of LSIs, and the operation of each configuration block executes each function. This is realized by one or a plurality of LSIs.
Further, the processing of the motor drive control device is executed by the following two loops.

One is a current formed mainly by the current PI control unit 12, the inverse Park conversion unit 13, the three-phase signal generation unit 14, the motor drive unit 15, the current acquisition unit 16, the Clark conversion unit 17, and the Park conversion unit 18. It is a control loop.
The other is a rotational speed control loop mainly including a speed PI control unit 11, an electrical angle estimation unit 19, and a rotational speed detection unit 22.
In the current control loop, the current PI control unit 12, the inverse Park conversion unit 13, the three-phase signal generation unit 14, the current acquisition unit 16, the Clark conversion unit 17, and the Park conversion unit 18 constitute the drive current control unit 20 described above. To do.

The drive current control unit 20 of the current control loop uses the field correction current value output from the field current PI control unit 24, the torque current that is the torque component of the drive signal contributing to the motor torque, and the motor The field current that is the field component of the drive signal that does not contribute to the torque is corrected. In particular, the field current is corrected so that a part of the regenerative power generated during the regenerative operation can be consumed by the motor.
When the field current is corrected by the drive current control unit 20 of the current control loop, the motor drive unit 15 generates a drive signal corresponding to the corrected field current and gives it to the motor.

In the current control loop, a three-phase drive signal (U, V, W) given from the motor drive unit 15 to the motor is monitored, and a two-phase measurement current corresponding to the three-phase drive signal is used to make a two-phase measurement. Monitor current (Iq, Id) is generated, and six three-phases are given to the motor drive unit 15 by vector conversion from the two-phase monitor current and the reference current information (torque target current Iqref, field target current Idref) A control signal (u, v, w, x, y, z) is generated, and further, a three-phase drive signal (U, V, W) for driving the motor is generated by the motor drive unit 15, and this loop is set to 1. By executing the rotation once, the rotor included in the motor is rotated by a predetermined angle.
As described above, the torque target current Iqref and the field target current Idref are the torque component of the three-phase drive signal given to the motor and the target current value of the field component, and the three-phase drive signal (U , V, W) are controlled so that the torque component and the field component become Iqref and Idref, respectively.

In the rotational speed control loop, the torque target current Iqref and the field target current Idref are generated so that the current rotational speed ω of the motor matches the target rotational speed ωref.
That is, after the current control loop is executed a plurality of times during a preset period, the current rotational speed ω of the motor is acquired by the speed PI control unit 11 and the rotational speed ω becomes the target rotational speed ωref. Reference current information (torque target current Iqref, field target current Idref) for adjusting to match is generated, and a field current for adjusting the field target current Idref by the field current PI control unit 24 is generated. A correction current ΔIdref is generated and applied to the current control loop.
When the current rotational speed ω of the motor is smaller than the target rotational speed ωref, the rotational speed is increased by increasing the torque target current Iqref. On the other hand, when the current rotational speed ω of the motor is larger than the target rotational speed ωref, the rotational speed is decreased by decreasing the torque target current Iqref.

As described above, in the present invention, motor drive control is performed by the current control loop and the rotation speed control loop. In particular, it is possible to prevent the temperature of the regenerative resistor from rising as much as possible during the regenerative operation. One of the objects of the invention.
That is, when the input voltage of the motor drive unit increases during the regenerative operation, the field current PI control unit 24 increases the field correction current value in accordance with the increase of the input voltage of the motor drive unit, and drives The current control unit 20 is characterized in that the regenerative power consumed by the motor is increased by correcting the field current so that the field current increases corresponding to the increased field correction current value.
In this way, by increasing the field current of the field component that does not contribute to the motor torque and increasing the regenerative power consumed by the motor, the consumption of the regenerative power due to the regenerative resistance is relatively reduced. The temperature increase of regenerative resistance can be suppressed.

FIG. 16 shows a flowchart of an embodiment of the motor drive control process in the autonomous mobile device of the present invention.
In step S1 of FIG. 16, an initial value T1 is set in the timer T.
The initial value T1 initially set in the timer T corresponds to a cycle in which the rotation speed control loop is repeated.
Each time the timer T times out, the next rotation speed control loop is started.
Further, the current control loop is repeated several times during the period of one rotation speed control loop.
In step S2, speed PI control by the speed PI control unit 11 is performed.
In step S3, the field current PI control by the field current PI control unit 24 is performed.

The next processing from step S4 to step S11 corresponds to the processing of the current control loop.
In step S4, the rotation speed detector 22 detects the rotor rotation speed.
In step S5, the electrical angle estimation unit 19 performs electrical angle estimation processing.
In step S6, the current acquisition unit 16 performs current value acquisition processing.
In step S7, the Clark conversion process by the Clark conversion unit 17 is performed.
In step S8, Park conversion processing by the Park conversion unit 18 is performed.
In step S9, current PI control processing by the current PI control unit 12 is performed.
In step S10, reverse Park conversion processing by the reverse Park conversion unit 13 is performed.

  In step S11, a three-phase signal generation (SVPWM generation) process by the three-phase signal generation unit 14 is performed. By this three-phase signal generation process, a three-phase control signal (u, v, w, x, y, z) output to the motor drive unit 15 is generated. When a three-phase control signal is given to the motor drive unit 15, the motor drive unit 15 outputs a three-phase drive signal (U, V, W) to the motor 21, and the motor 21 rotates corresponding to the three-phase drive signal. Be made.

In step S12, the timer T is decreased by 1 and updated.
In step S13, it is checked whether or not the timer T has timed out (T = 0).
If the timer T has timed out, the process returns to step S1 and the above processing is repeated.
On the other hand, if the timer T has not timed out, the process returns to step S4, and the current control loop process from step S4 to step S11 is repeated.
By repeatedly performing such motor drive control processing, the rotation speed of the motor is changed, the wheels connected to the rotation shaft of the motor are rotated, and the traveling of the autonomous traveling device is controlled.

<Description of schematic configuration of motor drive unit>
FIG. 2 shows a block diagram of the first embodiment of the motor drive unit of the present invention.
In FIG. 2, the motor drive unit (inverter) 15 mainly includes six transistors 51 to 56 (Tr1 to Tr6) arranged as shown in the figure.
The three-phase control signals (u, v, w, x, y, z) generated by the three-phase signal generator 14 are input to the transistors (51 to 56), respectively, and based on the three-phase control signals, Each transistor is on-controlled or off-controlled.

For example, a set of transistors Tr1 and Tr4 receives a three-phase control signal u and a three-phase control signal x obtained by inverting the signal u.
A signal flowing through the line connecting the one set of transistors Tr1 and Tr4 is extracted and given to the motor 21 as one three-phase drive signal U.

In addition, a set of transistors Tr2 and Tr5 is respectively input with a three-phase control signal v and a three-phase control signal y obtained by inverting the signal v, and a line connecting the set of transistors Tr2 and Tr5 is connected. The flowing signal is extracted and given to the motor 21 as one three-phase drive signal V.
Further, the three-phase control signal w and the three-phase control signal z obtained by inverting the signal w are input to the pair of transistors Tr3 and Tr6, respectively, and a line connecting the pair of transistors Tr3 and Tr6 is connected. The flowing signal is extracted and given to the motor 21 as one three-phase drive signal W.

Further, in order to monitor three three-phase drive signals (U, V, W) for driving the motor, three-phase measurement currents (Iu, Iv, Iw) corresponding to the three-phase drive signals are supplied to the current acquisition unit 18. Output.
The three-phase measurement currents (Iu, Iv, Iw) correspond to currents drawn from the three sets of transistors (Tr1, Tr2, Tr3) or (Tr4, Tr5, Tr6), respectively.

Further, as shown in FIG. 2, the rechargeable battery 23 is connected so that the power supply voltage Vdd of the rechargeable battery 23 is supplied to the motor drive unit (inverter) 15, and the voltage sensor detects the input voltage Vdd of the motor drive unit. 63 are connected in parallel.
The input voltage Vdd of the motor driving unit detected by the voltage sensor 63 is given to the field current PI control unit 24 as shown in FIG.

Furthermore, the transistor Tr0 (61) and the regenerative resistor R0 (62) connected in series are connected to the input of the motor drive unit.
The transistor Tr0 (61) is an element that controls whether or not a regenerative current flows through the regenerative resistor R0 (62).
Although not shown, a signal for controlling the transistor Tr0 (61) to be turned off or on based on the value of the input voltage Vdd of the motor driving unit detected by the voltage sensor 63 is a transistor Tr0 (61). An electronic circuit that outputs the signal is provided around the voltage sensor 63.

When the regenerative operation is not performed, it is not necessary to consume regenerative power at the regenerative resistor R0 (62), so the transistor Tr0 (61) is controlled to be in an off state, and no current flows through the regenerative resistor R0 (62). .
On the other hand, when the input voltage Vdd of the motor driving unit detected by the voltage sensor 63 rises to a predetermined value or more, the transistor Tr0 (61) is controlled to be turned on by a signal output from the voltage sensor 63, A current is caused to flow through the regenerative resistor R0 (62).
That is, in the case of performing the regenerative operation, an increase in the input voltage Vdd of the motor drive unit is suppressed by passing a current through the regenerative resistor R0 (62).

<Description of schematic configuration of field current PI controller>
FIG. 3 shows a configuration block diagram of the first embodiment in the field current PI control unit of the present invention.
As described above, the field current PI control unit 24 uses the input voltage Vdd of the motor driving unit and the reference voltage Vddref supplied from the control unit 10 as input data, and outputs the field correction current ΔIdref.
As shown in FIG. 3, the field current PI control unit 24 mainly includes a subtractor 71, a multiplier 72, a multiplier 73, an integrator 74, an adder 75, and a limiter 76.

Here, the subtractor 71, the multiplier 72, the multiplier 73, the integrator 74, and the adder 75 correspond to a target value generation unit.
The target value generation unit receives the power supply voltage and the reference voltage read from the storage unit, and generates a field current target value ΔId, which will be described later, based on the difference between the input power supply voltage and the reference voltage.

The limiter 76 sets an upper limit value of the field current target value ΔId. The limiter 76 receives the generated field current target value ΔId and inputs the generated field current target value ΔId or a preset value. One of the upper limit values (Idrmx) of the field current target value ΔId is output as the field correction current value ΔIdref.
That is, when the generated field current target value ΔId is equal to or larger than a preset upper limit value, the upper limit value (Idrmx) is output as a field correction current value, and the generated field current target value ΔId is When the value is smaller than the upper limit value (Idrmx), the generated field current target value ΔId is output as a field correction current value.

The subtracter 71 outputs a voltage value (difference: Vdd−Vddref) obtained by subtracting the reference voltage Vddref from the input voltage Vdd of the motor drive unit.
The difference is given to each of the two multipliers.
The multiplier 72 multiplies the proportional term of the difference by a predetermined constant Kp.
The multiplier 73 and the integrator 74 multiply the difference integral term by a predetermined constant Ki, and then perform an integral operation.

However, since the field correction current ΔIdref is a value greater than or equal to zero, the difference integral term is also set to a value greater than or equal to zero, and the value of the difference integral term output from the integrator 74 is a negative number. The value of the integral term of the difference output from the integrator 74 is rounded up to zero and output.
The proportional term of the difference output from the multiplier 72 and the integral term of the difference output from the integrator 74 are added by the adder 75.
The numerical value after the addition by the adder 75 is referred to as a field current target value ΔId.

The field current target value ΔId may be output as it is and supplied to the adder 25 of FIG. 1. However, in order to prevent an undesired phenomenon from occurring for reasons described later, the field current target value ΔId is not generated. Set an upper limit for.
The field current target value ΔId is given to the limiter 76, and the limiter 76 generates a field correction current ΔIdref in which the upper limit value (Idrmx) is set.
In the limiter 76, an upper limit value (Idrmx) is set in advance, and when the field current target value ΔId is smaller than the upper limit value (Idrmx), the field current target value ΔId is directly output as the field correction current ΔIdref. To do. On the other hand, when the field current target value ΔId is equal to or greater than the upper limit value (Idrmx), the field current target value ΔId is limited, and the upper limit value Idrmx is output as the field correction current ΔIdref.

FIG. 4 shows an example of a characteristic graph in the limiter of the field current PI controller of the present invention.
FIG. 4 shows a graph showing the relationship between the field current target value ΔId and the field correction current ΔIdref.
An upper limit (Idrmx) is set in advance for the field correction current ΔIdref.
Here, even if the field current target value ΔId is equal to or greater than ΔId0, for example, it means that the upper limit value (Idrmx) corresponding to ΔId0 is output as the field correction current ΔIdref.

The reason why an upper limit is set for the field current target value ΔId will be described with reference to FIG.
FIG. 5 is a schematic explanatory diagram of the motor driving operation when the input voltage of the motor driving unit is increased.
In FIG. 5, in order to briefly explain the motor driving operation when the input voltage of the motor driving unit is increased, the motor 21, a part of the motor driving unit 15, and a component part made up of a rechargeable battery are cut out. .
In order to simplify the explanation, a part of the motor drive unit 15 includes four transistors (Q0, Q1, Q2, Q3) and a free-wheeling diode (D0, D1, D2, D3) connected in parallel to each transistor. Show.
A line drawn from the connection point of one set of transistors (Q0, Q1) and the connection point of another set of transistors (Q2, Q3) is connected to the coil L of the motor 21.

During the regenerative operation, a counter electromotive force Vm is generated in the coil L of the motor 21.
The input voltage Vdd of the motor drive unit is applied to the two sets of transistors, and the voltage across the capacitor C corresponds to the voltage (referred to as the bus voltage Vbus) applied across the two sets of transistors.

As will be described below, when the upper limit is not set for the field current target value ΔId, the field current Id increases excessively and the following phenomenon occurs, so that the motor operation becomes unstable.
First, when the regenerative operation starts, even when the back electromotive force Vm of the motor 21 is smaller than the bus voltage Vbus, the transistor of the inverter 15, the freewheeling diode, and the motor coil constitute a boost chopper circuit. Vbus rises.
Therefore, it normally operates with Vbus> Vm.

Thereafter, when the bus voltage Vbus increases, the field current PI control unit 24 generates the field current target value ΔId so as to increase the field current Id.
However, when the field current Id increases, the magnetic flux density of the coil L increases, so that the back electromotive force Vm increases. However, the effect of reducing the bus voltage Vbus is effective while Vbus> Vm is established.

If the field current Id is continuously increased, Vbus <Vm is finally obtained.
At this time, the current flows backward via the freewheeling diode, and the bus voltage Vbus starts to rise.

Since the bus voltage Vbus rises, the field current PI control unit 24 increases the field current target value ΔId.
As a result, the field current Id increases, and accordingly, the counter electromotive force Vm rises and the bus voltage Vbus further rises.

When this circulation continues, the field current Id increases abruptly. When the field current Id increases, the rotor sticks to the magnetic field in the field direction and stops rotating.
When the rotor stops, the back electromotive force Vm becomes 0, and the original normal state in which the motor can be driven is restored.

As described above, when the upper limit is not set for the field current target value ΔId, the above operation is repeated, and the traveling operation becomes unstable.
Therefore, in order to continue running stably, an upper limit is set to the field current target value ΔId so that the field current Id does not increase excessively, and the field current Id is controlled in a region where Vbus> Vm. There is a need to.
The back electromotive force Vm of the motor can be determined by the product of the constant k, the magnetic flux density φ (proportional to the field current), and the rotation speed n. Therefore, if the maximum value of the rotation speed n is determined, the maximum value of the field current, that is, the upper limit value (Idrmx) of the field current target value ΔId can be uniquely determined.
The upper limit value of the field current target value ΔId corresponds to the upper limit value Idrmx of the field correction current ΔIdref.

As described above, in the first embodiment, the field current PI control unit 24 is provided, and the field current PI control unit 24 uses the input voltage Vdd and the reference voltage Vddref of the motor drive unit as input data and performs a predetermined calculation. Thus, the field current target value ΔId is calculated, and the field correction current ΔIdref is output. By using this field correction current ΔIdref, the field current Id is controlled in the current control loop.
When the input voltage Vdd of the motor drive unit rises above the reference voltage Vddref due to the occurrence of regenerative operation, the field current target value ΔId is increased, and the field component field that does not contribute to the motor torque is increased. By controlling so that the magnetic current Id increases, the increase of the input voltage Vdd of the motor drive unit is suppressed, and the heat generation of the regenerative resistor is suppressed.

Thereby, it is possible to prevent a situation in which autonomous traveling cannot be performed as much as possible, and to extend the continuous traveling time of the autonomous traveling device.
Further, by setting an upper limit in advance for the field current target value ΔId, it is possible to avoid the rotation of the motor as described above from falling into an unstable circulation and to ensure stable running.

(Second Embodiment of Autonomous Traveling Device)
<Configuration of motor drive control of autonomous traveling device>
FIG. 6 shows a block diagram of a second embodiment of the configuration relating to the motor drive control device of the autonomous traveling device of the present invention.
Here, the rotational speed ω of the motor generated by the electrical angle estimation unit 19 is input to the field current PI control unit 24.
The field current PI control unit 24 sets the maximum value of the field correction current ΔIdref output from the limiter 76 using the input rotation speed ω.

For example, the limiter 76 sets the maximum value of the field correction current value to a value lower than the upper limit value of the field current target value corresponding to the input rotational speed ω, and the rotational speed ω is equal to or higher than a predetermined value. The field current PI control unit 24 decreases the maximum value of the field correction current as the rotational speed ω increases.
As shown below, when the rotational speed ω is increased, the maximum value of the field correction current ΔIdref is set lower than the preset upper limit value Idrmx of the field correction current ΔIdref, thereby making autonomous driving more It can be stabilized.

In FIG. 6, each component and its connection relationship are substantially the same as those in the block diagram of the first embodiment shown in FIG. 1, but the rotational speed ω output from the electrical angle estimator 19 represents the field current. The input to the PI control unit 24 is different from the first embodiment.
Since the processing of each component block is the same as that of the first embodiment, description thereof is omitted.
The rotational speed ω is given to the limiter 76 of the field current PI control unit 24.

FIG. 7 shows a configuration block diagram of the second embodiment in the field current PI controller of the present invention.
In FIG. 7, each component and its connection relationship are substantially the same as those in the block diagram of the first embodiment shown in FIG. 3, but the rotational speed ω output from the electrical angle estimator 19 is applied to the limiter 76. The input is different from the first embodiment.
The characteristics of the limiter 76 shown in FIG. 3 are fixed in advance as shown in FIG. 4, and the maximum value of the field correction current ΔIdref is also set in advance to one fixed value (upper limit value Idrmx).
However, in the second embodiment, the maximum value of the field correction current ΔIdref is changed in accordance with the numerical value of the rotational speed ω.

FIG. 8 shows an example of a characteristic graph showing the relationship between the rotation speed and the maximum value of the field correction current in the limiter of the field current PI controller of the present invention.
Here, the upper limit value of the maximum value of the field correction current ΔIdref is defined as Idrmx.

FIG. 8A shows a characteristic in which the maximum value of the field correction current ΔIdref decreases nonlinearly as the rotational speed ω increases.
For example, the upper limit value Idrmx is adopted as the maximum value of the field correction current ΔIdref until the rotation speed ω reaches the predetermined value ω0, but when the rotation speed ω increases to the predetermined value ω0 or more, the field correction current ΔIdref Is set to be lower than the upper limit value Idrmx.

As described above, the counter electromotive force Vm is determined by the product of the constant k, the magnetic flux density φ (proportional to the field current), and the rotation speed n, so the counter electromotive force Vm is proportional to the rotation speed n.
That is, when the rotational speed n increases, the counter electromotive force Vm also increases in proportion to the rotational speed n. This is because when the rotational speed ω corresponding to the rotational speed n per unit time increases, the counter electromotive force Vm Also means rising.
When the back electromotive force Vm rises, the above-described rotor sticks to the magnetic field in the magnetic field direction and the rotation stops, and the traveling operation becomes unstable.

Therefore, when the rotational speed ω increases, the increase in the back electromotive force Vm can be suppressed by reducing the maximum value of the field correction current ΔIdref.
In other words, by setting the maximum value of the field correction current ΔIdref to be lower than the upper limit value Idrmx in response to the increase in the rotational speed ω, the increase in the back electromotive force Vm is suppressed, and autonomous running is further stabilized. Can be continued for a longer time.

FIG. 8B shows a characteristic that the maximum value of the field correction current ΔIdref decreases linearly as the rotational speed ω increases. It is easier to handle the control when it is changed linearly than when it is changed non-linearly.
As described above, even when the limiter characteristic is changed linearly, the increase in the counter electromotive force Vm is suppressed as in the case of FIG. 8A, and the autonomous running can be further stabilized.

(Third embodiment of autonomous traveling device)
<Configuration of motor drive control of autonomous traveling device>
FIG. 9 shows a block diagram of a third embodiment of the configuration relating to the motor drive control device of the autonomous traveling device of the present invention.
Here, a temperature sensor 64 for measuring the temperature Temp of the inverter 15 as shown in FIG. 10 described later is provided, and the measured temperature Temp of the inverter 15 is input to the field current PI control unit 24.
Further, the field current PI control unit 24 sets the maximum value of the field correction current ΔIdref output from the limiter 76 using the input temperature Temp of the inverter.

For example, the limiter 76 sets the maximum value of the field correction current value to a value lower than the upper limit value of the field current target value corresponding to the input temperature Temp, and the input temperature Temp becomes equal to or higher than a predetermined value. When it rises, the field current PI control unit 24 reduces the maximum value of the field correction current value as the input temperature Temp rises.
As shown below, when the temperature Temp of the inverter increases, the maximum value of the field correction current ΔIdref is set lower than the preset upper limit value Idrmx of the field correction current ΔIdref. It can be made more stable.

In FIG. 9, each component and its connection relationship are substantially the same as those in the block diagrams shown in FIGS. 1 and 6, but the measured inverter temperature Temp is input to the field current PI control unit 24. This is different from the first and second embodiments.
Since the processing of each component block is the same as that of the first embodiment, description thereof is omitted.
The measured temperature Temp of the inverter is supplied to the limiter 76 of the field current PI control unit 24.

FIG. 10 shows a block diagram of a third embodiment of the motor drive unit of the present invention.
Similarly to the motor drive unit 15 shown in FIG. 2, the motor drive unit 15 shown in FIG. 10 includes six transistors.
The connection and operation of the six transistors are the same as those shown in the description of FIG.
As shown in FIG. 10, a temperature sensor 64 is provided in the motor drive unit 15.
The temperature sensor 64 corresponds to the first temperature measurement unit described above.

For example, when the motor driving unit 15 is configured by one IC circuit, the temperature sensor 64 may be disposed so as to contact the IC circuit.
Alternatively, in the case where the transistor is composed of individual components, the temperature sensor 64 may be disposed on the heat sink of the transistor.
The temperature sensor 64 measures the temperature Temp of the motor drive unit (inverter) 15.
The inverter temperature Temp measured by the temperature sensor 64 and the input voltage Vdd of the motor drive unit measured by the voltage sensor 63 are input to the field current PI control unit 24.

FIG. 11 shows a configuration block diagram of the third embodiment in the field current PI control unit of the present invention.
In FIG. 11, each component and its connection relation are almost the same as those in the block diagrams shown in FIGS. 3 and 7, but the temperature Temp of the inverter is input to the limiter 76 in the second embodiment. And different.
In the characteristic of the limiter 76 shown in FIG. 4, the maximum value of the field correction current ΔIdref is preset to one fixed value (upper limit value Idrmx). In the characteristic of the limiter 76 shown in FIG. In the third embodiment, the maximum value of the field correction current ΔIdref is changed in accordance with the numerical value of the inverter temperature Temp. .

FIG. 12 shows an example of a characteristic graph showing the relationship between the inverter temperature and the maximum value of the field correction current in the limiter of the field current PI controller of the present invention.
Again, the upper limit value of the maximum value of the field correction current ΔIdref is assumed to be Idrmx.

FIG. 12 shows a characteristic in which the maximum value of the field correction current ΔIdref decreases linearly as the inverter temperature Temp increases.
For example, even if the temperature Temp of the inverter rises, the maximum value Idrmx is used as the maximum value of the field correction current ΔIdref until the predetermined value T0, but when the temperature Temp rises above the predetermined value T0, The maximum value of the field correction current ΔIdref is set to be lower than the upper limit value Idrmx.

As described above, when the field current Id is increased and the regenerative power is consumed by the motor itself, the current flowing through the inverter 15 increases. When the current flowing through the inverter 15 increases, the semiconductor components constituting the inverter 15 such as six transistors generate heat, and the temperature of the inverter 15 rises.
Since the maximum temperature value is predetermined for the rating of the semiconductor component, if the temperature of the inverter 15 exceeds this maximum temperature value, the semiconductor component may be damaged.

Therefore, it is necessary to reduce the field current Id so that the temperature of the inverter 15 does not exceed the maximum temperature value.
That is, the maximum value of the field correction current ΔIdref is set lower than the upper limit value Idrmx in accordance with the increase in the temperature Temp of the inverter 15. As a result, the increase in the field current Id is suppressed, and the temperature of the inverter 15 is controlled so as not to exceed the rated maximum temperature value, so that the semiconductor components of the inverter 15 are prevented from being damaged, and the stable autonomous traveling Can do.

Further, the second embodiment shows an example in which the rotational speed ω is input to the limiter 76 and the maximum value of the field correction current ΔIdref is set. In the third embodiment, the temperature Temp of the inverter 15 is input to the limiter 76. In this example, the maximum value of the field correction current ΔIdref is set. However, the field correction current ΔIdref to be output may be set by combining the two embodiments.
For example, the limiter 76 having the configuration of FIG. 7 and the limiter 76 having the configuration of FIG. 11 are connected in parallel, and the same field current target value ΔId is input to the two limiters 76 at the same time. Of the field correction currents ΔIdref output from, the smaller field correction current ΔIdref may be adopted.

(4th Embodiment of an autonomous traveling apparatus)
In the third embodiment described above, the temperature sensor 64 for measuring the temperature Temp of the inverter 15 is provided. When the temperature Temp of the inverter rises, the maximum value of the field correction current ΔIdref is set to a preset field correction current. A description has been given of what stabilizes autonomous traveling by setting it lower than the upper limit value Idrmx of ΔIdref.
However, by controlling the field current based on the inverter temperature Temp, even if stable autonomous driving is possible on the downhill, the regenerative power is consumed by the motor, so the inverter temperature Temp rises considerably. In this case, for example, because the inverter is already at a high temperature despite the fact that the next travel route has a long and steep climb and a large torque is required, the drive current flowing to the motor may be increased. It may not be possible.

As described above, the method of consuming regenerative power includes power consumption by the regenerative resistor 62 and power consumption by the motor itself by increasing the field current Id.
Power consumption due to regenerative resistance alone leads to an increase in the temperature of the regenerative resistance, while power consumption by the motor itself by increasing the field current Id leads to an increase in the inverter temperature Temp, both of which are excessively An increase in temperature can cause problems for autonomous driving.

Therefore, it is preferable that autonomous driving can be performed as stably as possible by properly combining the methods of consuming two regenerative electric powers in response to the increase in the temperature of the regenerative resistor and the increase in the temperature Temp of the inverter.
In the fourth embodiment, a temperature sensor is also provided in the regenerative resistor 62, the temperature of the regenerative resistor and the temperature Temp of the inverter are measured, and a method of consuming two regenerative electric powers is properly used.

FIG. 13 shows a block diagram of a fourth embodiment of the motor drive unit of the present invention.
The motor drive unit (inverter) 15 in FIG. 13 includes six transistors, similar to the motor drive unit 15 illustrated in FIG. 2, and similarly to the motor drive unit 15 illustrated in FIG. A temperature sensor 64 is provided.
Further, in the motor drive unit (inverter) 15 of FIG. 13, a temperature sensor 65 is provided in the regenerative resistor 62.
The temperature sensor 65 measures the temperature TempR of the regenerative resistor 62 and corresponds to the above-described second temperature measurement unit.
The temperature TempR of the regenerative resistor 62 measured by the temperature sensor 65 is given to the field current PI control unit 24.
The temperature sensor 65 may be disposed so as to contact the regenerative resistor 62.

In the fourth embodiment, the temperature TempR of the regenerative resistor 62 measured by the temperature sensor 65, the temperature Temp of the inverter 15 measured by the temperature sensor 64, and the input voltage Vdd of the motor drive unit measured by the voltage sensor 63 Is input to the field current PI control unit 24.
The field current PI control unit 24 changes the maximum value of the field correction current value in accordance with the input inverter temperature Temp and regenerative resistance temperature TempR.
Further, in the drive current control unit 20 constituting the current control loop, the field current is corrected in accordance with the field correction current value output from the field current PI control unit 24, so that the regenerative power generated by the regenerative resistor is reduced. The consumption and the consumption of regenerative power in the motor generated by increasing the field current are adjusted.
By adjusting the consumption of these two regenerative electric powers, the continuous running time of the autonomous mobile device is expanded.

FIG. 14 is a schematic explanatory diagram showing an embodiment of the correspondence relationship between the temperature of the motor drive unit and the regenerative power consumption according to the present invention.
This correspondence is equivalent to a criterion for determining which of the two regenerative power consumptions has priority.
In order to determine which of the two regenerative power consumptions has priority, for example, a control circuit that receives two temperatures (not shown) may be provided in the field current PI control unit 24.
FIG. 14 shows a consumption pattern of the regenerative power and a case where the traveling of the autonomous traveling device is stopped in correspondence with four combinations of the regenerative resistance temperature TempR and the inverter temperature Temp.

  Mainly, when the temperature TempR of the regenerative resistor is low, the consumption of the regenerative power by the regenerative resistor 62 is preferentially used, and when the temperature TempR of the regenerative resistor increases, the consumption of the regenerative power due to the increase of the field current Id. Is used preferentially, and in the state where the inverter temperature Temp is high, the consumption of the regenerative power by the regenerative resistor 62 is preferentially used. Further, when both the regenerative resistance temperature TempR and the inverter temperature Temp are high, the autonomous traveling device stops traveling.

In FIG. 14, “◎” of number 1 means that almost only the consumption of regenerative power by the regenerative resistor 62 is used.
Numbers 2 and 3 indicate that the corresponding regenerative power consumption is preferentially used, and “△” indicates that the corresponding regenerative power consumption is also used, but the priority is lower than the other. means.
The number “◎” of No. 4 means that the traveling of the autonomous traveling device is stopped without consuming regenerative power.
However, the determination criteria are not limited to those shown in FIG. 14, and other determination criteria may be used.

  In FIG. 14, the degree of temperature is divided into two, high temperature and low temperature, but there is no clear numerical value that distinguishes high temperature from low temperature. Depending on the resistance value of the regenerative resistor, the types of components that make up the inverter, the current value of the current flowing through the regenerative resistor, etc., the temperature that distinguishes the high temperature from the low temperature changes, and no clear value is set.

  In FIG. 14, when the inverter temperature Temp is relatively low and the regenerative resistance temperature TempR is also relatively low, there is almost no possibility that the regenerative resistor 62 is damaged. Is controlled so that regenerative power is not consumed due to an increase in the field current Id.

  In addition, although the regenerative resistance temperature TempR is relatively low, when the inverter temperature Temp rises to a relatively high temperature, the regenerative power consumption by the regenerative resistor 62 continues to be preferentially used. Control is made so that the consumption of regenerative power due to the increase of the field current Id is also used in accordance with the temperature.

  Also, when the inverter temperature Temp is relatively low, but the temperature TempR of the regenerative resistor rises and becomes relatively high, the consumption of regenerative power due to the increase of the field current Id is used preferentially, Control is made so that the consumption of the regenerative power by the regenerative resistor 62 is reduced or the consumption of the regenerative power by the regenerative resistor 62 is stopped.

  When the inverter temperature Temp is relatively high and the regenerative resistance temperature TempR is also relatively high, the regenerative power consumption by the regenerative resistor 62 may be continued, but the regenerative resistor and the inverter are damaged. In order to avoid this, it is preferable to stop the traveling of the autonomous traveling device without consuming regenerative power. Thereafter, when the regenerative resistance and the temperature of the inverter are lowered to some extent, it is preferable to restart the running.

(5th Embodiment of an autonomous traveling apparatus)
In the fifth embodiment, when the height difference (inclination) of the route traveled by the autonomous traveling device is known in advance, the consumption of regenerative power by the regenerative resistor 62 and the field corresponding to the position and region of the travel route are determined. A case will be described in which which of the regenerative power consumption due to the increase of the magnetic current Id is preferentially used is set.

  In an autonomous traveling device that autonomously travels for the purpose of patrol monitoring a predetermined premises, a traveling route may be set in advance. Therefore, for example, on the travel route, where the uphill starts, at which point the downhill ends, in which region the downhill continues, which region is a flat route before traveling Since it understands, there may be a case where the section of the travel route and the inclination can be stored in association with each other.

FIG. 15 is a schematic explanatory diagram of one embodiment showing the correspondence between the travel route and the regenerative power consumption of the autonomous traveling device of the present invention.
FIG. 15 (a) shows an example of a traveling route traveled by the autonomous traveling device, and the traveling route is divided into nine sections from section A to section I.
For example, section A, section D, and section I are sections with a flat slope, sections B and sections E to section H are down sections with different slopes, and section C is a climb section. Suppose there was.
Further, it is assumed that the section B is a downhill section having a relatively short distance, and the section from the section E to the section H is a downhill section having a relatively long distance. Therefore, during the travel in the section B and during the travel from the section E to the section H, the regenerative operation is performed and regenerative power is generated.

In such a travel route, since there is an uphill section C immediately after the downhill section B, the regenerative resistor 62 regenerates in the section B in preparation for an increase in the inverter temperature due to an increase in current on the uphill. It can be said that it is preferable to use power consumption preferentially.
In addition, since the downhill with a relatively long distance continues from the section E to the section H, the temperature of the regenerative resistor may be excessively increased only by the consumption of the regenerative power by the regenerative resistor 62. It can be said that it is preferable to preferentially use the regenerative power consumption due to the increase in Id.

Therefore, when the relation between the section of the route on which the autonomous traveling device travels and the inclination is known in advance, such as a traveling route, the section of the traveling route, the inclination, and the method of consuming regenerative power to be used preferentially It is only necessary to previously set and store the route inclination information associated with.
When the autonomous traveling device travels on a patrol route, it uses the stored slope information and uses the regenerative power consumption method according to the information set in the predetermined section of the travel route. Considering the temperature rise of the resistance and the inverter, it is possible to consume regenerative power suitable for the inclination (up and down) of the circulation route, and to perform stable long-time running.

For example, as shown in FIG. 15 (b), the relationship between the section of the route on which the autonomous traveling device travels, the inclination, the consumption of the regenerative power by the regenerative resistor 62, and the consumption of the regenerative power by the increase of the field current Id. The route inclination information shown may be stored in advance in a storage device such as a hard disk HDD.
The route inclination information stored during the traveling of the autonomous traveling device is read and the current position is compared with the section of the route inclination information. For example, the autonomous traveling device preferentially uses the consumption of regenerative power by the regenerative resistor 62. When entering the section in which it is set, the motor drive control device may be controlled so that the consumption of the regenerative power by the regenerative resistor 62 is preferentially used.

1 autonomous traveling device,
2 monitoring units,
3 Control unit,
4 Body,
5 wheels,
6 wheels,
7 Camera,
10 control unit,
10a storage unit,
11 Speed PI controller,
12 Current PI controller,
13 Inverse Park converter,
14 3-phase signal generator,
15 motor drive unit,
16 Current acquisition unit,
17 Clarke converter,
18 Park converter,
19 Electrical angle estimator,
20 drive current controller,
21 Motor 22 Rotation speed detector,
23 Power supply (rechargeable battery),
24 field current PI controller 25 adder,
51 transistors,
52 transistors,
53 transistors,
54 transistors,
55 transistors,
56 transistors,
61 transistors,
62 regenerative resistance,
63 Voltage sensor,
64 temperature sensor,
65 temperature sensor,
71 subtractor,
72 multiplier,
73 multiplier,
74 integrator,
75 adder,
76 limiter

Claims (9)

A motor,
A motor drive unit that generates a drive signal for driving the motor and outputs the drive signal to the motor;
A regenerative resistor that consumes regenerative power generated during regenerative operation;
Inputs an input voltage of the motor drive unit, and outputs a field correction current value for controlling a field current that is a field component of a drive signal that does not contribute to the torque of the motor based on a change in the input voltage. A field current PI control unit,
Using the field correction current value, the torque current that is the torque component of the drive signal that contributes to the torque of the motor and the field current that is the field component of the drive signal that does not contribute to the torque of the motor are corrected. A drive current control unit,
The drive current control unit corrects the field current so that a part of the regenerative power generated during the regenerative operation can be consumed by the motor,
The motor drive control device, wherein the motor drive unit generates the drive signal corresponding to the corrected field current. When the input voltage of the motor drive unit rises during the regenerative operation,
The field current PI control unit increases the field correction current value in response to an increase in the input voltage,
The drive current control unit increases the regenerative power consumed by the motor by correcting the field current so that the field current increases corresponding to the increased field correction current value. The motor drive control device according to claim 1. A storage unit that stores the reference voltage;
The field current PI controller is
A target value generating unit that further inputs the reference voltage and generates a field current target value based on a difference between the input voltage of the input motor driving unit and the reference voltage;
A limiter that sets an upper limit value of the field current target value,
If the generated field current target value is greater than or equal to the upper limit value, the upper limit value is output as the field correction current value, and the generated field current target value is greater than the upper limit value. 3. The motor drive control device according to claim 1, wherein when the value is smaller, the field current target value is output as the field correction current value. 4. An electrical angle estimation unit for generating a rotation speed of the motor;
The rotational speed is input to the field current PI control unit,
The limiter sets the maximum value of the field correction current value to a value lower than the upper limit value of the field current target value corresponding to the input rotation speed,
4. The field current PI control unit decreases the maximum value of the field correction current value as the rotation speed increases when the rotation speed increases to a predetermined value or more. The motor drive control device described in 1. A first temperature measuring unit for measuring the temperature of the motor driving unit;
The measured temperature of the motor drive unit is input to the field current PI control unit,
The limiter sets the maximum value of the field correction current value corresponding to the input temperature to a value lower than the upper limit value of the field current target value,
4. The field current PI control unit decreases the maximum value of the field correction current value as the input temperature rises when the input temperature rises above a predetermined value. The motor drive control device described in 1. A second temperature measuring unit for measuring the temperature of the regenerative resistor;
The measured temperature of the regenerative resistance is input to the field current PI control unit,
In response to the input temperature of the regenerative resistor, the field current PI control unit changes the maximum value of the field correction current value,
The drive current control unit corrects the field current in accordance with the field correction current value output from the field current PI control unit, and thereby consumes regenerative power by the regenerative resistor and the field current. The motor drive control device according to claim 3, wherein consumption of regenerative electric power in the motor generated by increasing a magnetic current is adjusted. A second temperature measuring unit for measuring the temperature of the regenerative resistor;
The measured temperature of the regenerative resistance is input to the field current PI control unit,
The field current PI control unit changes the maximum value of the field correction current value corresponding to the input temperature of the motor driving unit and the temperature of the regenerative resistor,
The drive current control unit corrects the field current in accordance with the field correction current value output from the field current PI control unit, and thereby consumes regenerative power by the regenerative resistor and the field current. The motor drive control device according to claim 5, wherein a consumption of regenerative electric power in the motor generated by increasing a magnetic current is adjusted. The car body,
A drive member for running the vehicle body;
A motor drive control device for controlling the drive member;
The autonomous driving device, wherein the motor drive control device is the motor drive control device according to any one of claims 1 to 7. The regenerative resistor consumes regenerative power generated during regenerative operation,
A field correction current for controlling a field current that is a field component of the drive signal that does not contribute to the torque of the motor based on a change in the input voltage of the motor drive unit that generates a drive signal for driving the motor Output the value
Using the output field correction current value, a torque current that is a torque component of the drive signal that contributes to the torque of the motor and a field current that is a field component of the drive signal that does not contribute to the torque of the motor To correct
The correction of the field current is a correction that allows a part of the regenerative power generated during the regenerative operation to be consumed by the motor.
When the input voltage of the motor drive unit rises during the regenerative operation,
In response to the increase of the input voltage, the field correction current value is increased,
By correcting the field current to increase the field current corresponding to the increased field correction current value, the regenerative power consumed by the motor is increased,
Generating a drive signal corresponding to the corrected torque current and the corrected field current;
A motor drive method of a motor drive control device, wherein the motor is driven by the drive signal.