Patent ID: 12246440

DESCRIPTION OF EMBODIMENTS

Embodiment

In the following, an embodiment (referred to as “the embodiment” in the following) according to an aspect of the invention is described with reference to the drawings. It is noted that the same components in the drawings are labeled with the same reference symbols, and the descriptions thereof will not be repeated.

1. Application Example

(Relationship Between Inrush Current Due to Electric Load and Voltage)

In general, a manipulator includes a multi-axis, high-output motor and a stable power device with a large capacity. Therefore, such manipulator may easily become very large as an electric load. In particular, since a high-output motor consumes a large amount of power to start when starting, the inrush current increases under the condition that the input voltage is low. Such property is not limited to high-output motors, but applies to any electric load that consumes a large amount of power when starting.

Comparatively, in the case of an electric load including a power device including a capacitor with a large electrostatic capacity on the input primary side and designed so that the output power is stable, such as a stable power device with a large capacity, the capacitor is charged immediately after the power is turned on. Therefore, the inrush current is present at the maximum value under the condition that the input voltage is high.

That is, the condition under which the inrush current increases differs as the type of electric load differs. That is, if a conventional electric apparatus in which multiple electric loads are combined is considered, it can be said that the inrush current of such electric apparatus varies with the properties of the electric loads and the state of the power voltage.

(Operation and Starting of an Electric Load by Using a Battery)

In addition, in the case where an electric load is driven by a battery, in order to operate the electric load, it is required that the power that the battery is able to supply exceed the rated power of the electric apparatus. In order to start the electric load, it is required that the inrush current of the electric apparatus is equal to or lower than the rated current value of the battery. In the mobile robot according to the embodiment, in the case where the voltage of the battery falls within a specific range, such as the case where the inrush current of the electric load is higher than a predetermined value, the starting of the electric load is disabled.

2. Configuration Example

FIG.1is a block diagram illustrating main components of a mobile manipulator1.

(Configuration of the Mobile Manipulator)

The mobile manipulator1includes a mobile robot2and a manipulator (electric load)31. The mobile robot2includes a controller10, a battery21, a voltage measurement unit22, and a traveling device23. The mobile robot2is an unmanned conveyor able to carry various electric apparatuses (electric loads). The controller10has a function of coordinating and controlling respective units of the mobile manipulator1.

The battery21is a secondary battery supplying power to the respective units (the controller10, the traveling device23, and the manipulator31) of the mobile manipulator1. The mobile manipulator1is charged by charging the battery21in a predetermined charging station or by replacing the battery21with a charged battery.

The voltage measurement unit22measures the voltage of the battery21. The voltage measurement unit22outputs the measured voltage to the controller10.

The traveling device23is a device that allows the mobile robot2to travel. The traveling device23operates by using the power supplied from the battery21.

The manipulator31is an electric load mounted in the mobile robot2. The electric load is not limited to the manipulator31, and may be any electric load. The manipulator31includes a multi-axis, high-output motor and a stable power device with a large capacity. Therefore, the inrush current at the time of starting tends to increase. For example, the electric load may be a conveyor, a motor, an electric cylinder, a vacuum pump, a DC-AC inverter, a DC-DC converter, a battery charger, a heat-retaining storage, a cold-insulating storage, or an arithmetic processing device that requires a large current, etc.

(Configuration of the Controller)

The controller10includes a voltage acquisition unit11, a condition determination unit12, a starting control unit13, an output control unit14, and an input unit15. The controller10may also control the operation of the traveling device23or the operation of the manipulator31.

The voltage acquisition unit11acquires the voltage measured by the voltage measurement unit22. The acquired voltage is transmitted to the condition determination unit12.

The condition determination unit12determines whether the acquired voltage falls within a specific range set in advance. The condition determination unit12transmits the determination result to the starting control unit13and the output control unit14. The specific range can be set arbitrarily.

The starting control unit13outputs a signal for starting the manipulator31in accordance with the determination result of the condition determination unit12. In the case where the condition determination unit12determines that the acquired voltage falls within the specific range, the starting control unit13disables the starting of the manipulator31, and in the case where the condition determination unit12determines that the acquired voltage does not fall within the specific range, the starting control unit13allows the starting of the manipulator31and starts the manipulator31. In addition, the starting control unit13allows the traveling device23to start and travel regardless of the result of the condition determination unit12(i.e., does not disable starting and operating).

In the case where the condition determination unit12determines that the acquired voltage falls within the specific range, the output control unit14uses an external device to notify the operator or a management server that the voltage of the battery21is not suitable for starting the manipulator31. When notifying, the output control unit14may also notify the operator by using an external device such as a display, a buzzer, or a signal tower not shown herein. The operator or the manager viewing the management server may replace or charge the battery21so that the measured voltage falls out of the specific range.

The input unit15possesses a function of setting the specific range used in the determination made by the condition determination unit12. The input unit15may perform communication with an external personal computer via a network, receive an input of changing the specific range, and set the specific range. The communication means may be of any communication standard, such as universal serial bus (USB, registered trademark), Ethernet (registered trademark) or Wi-Fi (registered trademark).

3. Operation Example

(Operation Example in the Case of Replacing the Battery21)

FIG.2is a flowchart illustrating a process of the mobile manipulator1in the case of replacing the battery21when the voltage of the battery21falls within the specific range. It is assumed that the charge residual amount of the battery21is sufficient for operating the mobile manipulator1.

In S11, the operator turns on the power of the mobile manipulator1. In order to reduce the inrush current, the mobile manipulator1does not turn on the power of the entire mobile manipulator1at the same time, but turns on the power in order, with priority, from the necessary components. That is, the mobile manipulator1initially turns on the power of the controller10, and then turns on the power of the voltage measurement unit22and the traveling device23. However, the power of the manipulator31is not turned on in S11, but turned on in a subsequent step.

In S12, the voltage measurement unit22measures the voltage of the battery21. The voltage acquisition unit11acquires the voltage of the battery21measured by the voltage measurement unit22. The voltage acquisition unit11transmits the acquired voltage of the battery21to the condition determination unit12.

In S13, the condition determination unit12determines whether the acquired voltage of the battery21falls within the specific range set in advance. The specific range is a setting value set by the input unit15, and is a voltage range of the battery21in which the starting of the manipulator31is disabled. The specific range is a voltage range that is a portion of a voltage range in which the manipulator31can be operated normally. The condition determination unit12transmits the determination result to the starting control unit13and the output control unit14.

In S13, in the case where the acquired voltage of the battery21does not fall within the specific range (NO in S13), the flow proceeds to S14. In S14, the starting control unit13turns on the power of the manipulator1(starts the manipulator1). This is because the acquired voltage of the battery21does not fall within the specific range, and therefore the output current of the battery21including the inrush current of the manipulator31is equal to or less than the rated current of the battery21. Therefore, the condition determination unit12determines that the power of the manipulator31may also be turned on. In addition to the inrush current of the manipulator31, the output current of the battery21also includes currents to other apparatuses (the controller10and the traveling device23, etc.) in operation. The controller10ends the starting process.

In S13, in the case where the acquired voltage of the battery21falls within the specific range (YES in S13), the flow proceeds to S15. In S15, the starting control unit13disables power-on (start) of the manipulator1. This is because the acquired voltage of the battery21falls within the specific range, and therefore the output current of the battery21including the inrush current of the manipulator31exceeds the rated current of the battery21. Therefore, the condition determination unit12determines that, once the power of the manipulator31is turned on, the battery21is damaged.

However, the starting control unit13only disables the power-on of the manipulator31, but does not disable the starting of the traveling device23. Therefore, with the condition determination unit12, even in the case where the voltage of the battery21falls within the specific range, the starting control unit13still allows traveling by using the traveling device23. The mobile manipulator1can be moved to any position, such as a charging/discharging station that performs charging/discharging, or an idling position that does not get in the way at the work site.

In addition, even if the voltage of the battery21falls within the specific range, the starting control unit13does not disable the manipulator31that has been started from continuing to operate. Even if the output voltage of the battery21falls within the specific range, it is possible for the manipulator31to be operated normally by using the battery21. Therefore, even if the voltage of the battery21falls within the specific range during operation of the manipulator31, the starting control unit13does not turn off the power of the manipulator31, and the operation of the manipulator31continues. The magnitude of the inrush current when an electric load (e.g., the manipulator31) is started changes in accordance with the output voltage of the battery21. Therefore, the output voltage range (specific range) in which the inrush current is excessively large differs in accordance with the electric load mounted in the mobile robot.

For example, if the electric load is an electric load designed to consume a certain amount of power at the time of starting of the electric load, the inrush current is greater than the predetermined value in a voltage range in which the output voltage of the battery21is low. In such case, in the voltage range (from A to B) in which the electric load is operable, a range from A to C may be set as the specific range (A<C<B).

Meanwhile, if the electric load is an electric load that includes a power device including a capacitor with a large electrostatic capacity on the input primary side and designed to stabilize the output voltage, the inrush current is greater than the predetermined value in a voltage range in which the output voltage of the battery21is low. In such case, in the voltage range (from A to B) in which the electric load is operable, a range from A to D may be set as the specific range (A<D<B).

For example, in an electric load including power devices of multiple systems, the two tendencies may overlap. Additionally, the start timing of each power device may differ in accordance with the electric load. Therefore, there are also electric loads whose inrush currents are greater than the predetermined value in an intermediate voltage range. In such case, in the voltage range (from A to B) in which the electric load is operable, a range from C to D may be set as the specific range (A<C<D<B). In addition, in the case where the inrush current is greater than the predetermined value in multiple voltage ranges separated from each other, the corresponding multiple voltage ranges may be set as the specific ranges.

It is noted that the battery21also supplies power other than to the electric load. For example, a voltage range in which a sum of the current supplied to other apparatuses (the traveling device, etc.) by the battery21and the inrush current of the electric load exceeds the rated current of the battery21is set as the specific range.

In S16, the output control unit14uses the external device such as a display, a buzzer, or a signal power not shown herein and notifies the operator that the power of the manipulator31cannot be turned on because the voltage of the battery21falls within the specific range. At this time, the output control unit14may also notify the management server in addition to or other than notifying the operator.

In S17, upon receipt of the notification of the output control unit14, the operator may replace the battery21of the mobile manipulator1with a charged battery21. In the case where the operator replaces the battery21with a charged battery21, the controller10processes S12again, measures the voltage of the battery21, and starts the manipulator31through the work processes of S13to S14.

Modified Examples

The starting timing of the manipulator31is not limited to the time when the mobile manipulator1is started. During a period in which the manipulator31is not used, the mobile manipulator1may turn off the power of the manipulator31and travel. At the timing of using the manipulator31, the mobile manipulator1may perform the steps after S12to start the manipulator31.

Although an example in which the battery21supplies power to the traveling device23and the manipulator31is described, the invention is not limited thereto. The mobile robot2may also include a battery different from the battery21in order to supply power to the traveling device23and the controller10. The battery21may also be additionally installed to the mobile robot2in accordance with the electric load mounted in the mobile robot2.

The mobile robot2may also include, in addition to the controller10, a controller controlling the operation of the traveling device23or the operation of the manipulator31.

(Operation Example in the Case of Charging/Discharging the Battery21)

FIG.3is a flowchart illustrating a process of the mobile manipulator1in the case of charging/discharging the battery21when the voltage of the battery21falls within the specific range.

InFIG.3, S17inFIG.2is replaced by S18. In S18, the mobile manipulator1moves to a charging station not shown herein by using the traveling device23. In the case where a lower voltage range in the voltage range in which the electric load is operable is the specific range, the charging station charges the battery21. Comparatively, in the case where a higher voltage range in the voltage range in which the electric load is operable is the specific range, the charging station discharges the battery21. That is, the charging station charges/discharges the battery21so that the voltage of the battery21falls out of the specific range. In addition, in the case where the mobile manipulator1has moved to the charging station, without further movement, the charging/discharging station performs charging/discharging so that the voltage of the battery21falls out of the specific range.

In particular, in the case where the specific range is a high voltage range, with replacement with the charged battery21, the output of the battery21naturally becomes a high voltage. As a result, the manipulator31cannot be started. Therefore, if the battery21is discharged to a suitable voltage by using the charging/discharging station, the manipulator31can be started.

4. Functions and Effects

At the time of the starting of the manipulator31, by using the condition determination unit12, whether the output current of the battery21including the inrush current of the manipulator31can be determined in accordance with whether the voltage of the battery21falls within the specific range. In the case where the output current of the battery21including the inrush current is greater than the rated current, the manipulator31cannot be normally started, and the battery21may be damaged. Alternatively, it is possible that, due to the operation of a protection circuit of the battery21, the battery21stops outputting, and the traveling device23, etc., does not operate. Therefore, in the case where the inrush current is greater than the rated current, it is an effective solution that the mobile robot2disables the power-on of the manipulator31.

In addition, even in the situation in which the voltage of the battery21falls within the specific range and the power-on of the manipulator31is disabled, the starting control unit13can turn on the power of the traveling device23and allow the mobile manipulator1to travel. Therefore, by using the traveling device23, the mobile manipulator1can move to the charging/discharging station and charge/discharge the voltage of the battery21to a voltage not falling within the specific range.

Moreover, the output control unit14can notify the operator or the management server that the voltage of the battery21falls within the specific range and the power-on of the manipulator31is disabled. Therefore, the operator or the management server can replace the battery21of the mobile manipulator1with a charged battery21or move the mobile manipulator1to the charging station by using the traveling device23to be charged or discharged.

In addition, the input unit15can receive an external input, and arbitrarily set the specific range. Therefore, even if the configuration of the mobile manipulator1is changed, the battery21can be prevented from being damaged by changing the setting of the specific range. The user can mount any electric load to the mobile robot and set the specific range in accordance with the electric load.

Embodiment 2

Another embodiment of the invention will be described in the following. For the convenience of description, components having the same functions as components having been described in the above embodiment are labeled with the same reference symbols and the descriptions thereof will not be repeated.

FIG.4is a block diagram illustrating main components of a mobile manipulator1a. The mobile manipulator1ais different from the mobile manipulator1, and includes a mobile robot2aand the manipulator31. The mobile robot2ais different from the mobile robot2, and includes a controller10ain place of the controller10. The controller10ais different from the controller10, and includes a configuration grasping unit16in place of the input unit15.

The configuration grasping unit16grasps a system configuration from a changed part of the operation program in a state in which the configuration of the mobile manipulator1ais changed and the operation program is changed. For example, the configuration grasping unit16specifies the electric load mounted to the mobile robot2from the operation program. The values of the inrush currents at respective voltages corresponding multiple electric loads may be recorded in advance in the configuration grasping unit16. By measuring the inrush currents at the respective voltages with respect to the electric loads in advance, the user can record the values of the inrush currents in the configuration grasping unit16in advance. In addition, the current values when multiple other apparatuses (the controller10, the traveling device23, various sensors, and display apparatuses, etc.) that may be included in the mobile robot2are operating (or in a steady state) may also be recorded in the configuration grasping unit16. Alternatively, multiple specific ranges respectively suitable for multiple electric loads may also be recorded in the configuration grasping unit16in advance. From such information, the configuration grasping unit16specifies the specific range of the voltage of the battery21so that the sum of the currents when other apparatuses included in the mobile robot2are operating and the inrush current of the electric load does not exceed the rated current of the battery21. The configuration grasping unit16sets the specified new specific range in the condition determination unit12. Accordingly, the configuration grasping unit16can grasp a change or addition of other apparatuses included in the mobile robot2(change of system configuration), and set the specific range suitable for the changed system configuration.

The configuration grasping unit16is not limited to grasping the system configuration based on a change of the operation program, but may also communicate with a configuration apparatus, an IO-Link (registered trademark), etc., and detect a system change. The configuration grasping unit16can obtain information such as the model of the configuration apparatus or the consumed power from the configuration apparatus itself. The configuration grasping unit16may change the specific range.

Therefore, the configuration grasping unit16can detect a change of the system configuration and grasp the system configuration without a setting input of the operator, thereby changing the specific range. As a result, the condition determination unit12can perform determination in the new specific range in the new system configuration and prevent the battery21from being damaged.

Embodiment 3

FIG.5is a block diagram illustrating main components of a mobile manipulator1b. The mobile manipulator1bis different from the mobile manipulator1, and includes a mobile robot2band the manipulator31. The mobile robot2bis different from the mobile robot2, and further includes a voltage transformation device32.

The voltage transformation device32, for example, includes a DC-DC converter33and a power multiplexer34. The power multiplexer34is a device that switches a power system by using an electromagnetic contact, a relay, or a semiconductor circuit. The voltage of the battery21is input to the DC-DC converter33and the power multiplexer34of the voltage transformation device32. The output voltage of the DC-DC converter33is input to the power multiplexer34. The output voltage of the power multiplexer34is supplied to the manipulator31. The power multiplexer34follows the command of the starting control unit13to switch which input is to be output to the manipulator31.

The voltage transformation device32is an apparatus that steps up or down the voltage input from the battery21, and supplies power to the manipulator31. In the case where the specific range is set to a low voltage, the voltage transformation device32steps up the voltage, and in the case where the specific range is set to a high voltage, the voltage transformation device32steps down the voltage, and transforms the voltage input to the manipulator31to a voltage outside the specific range. The voltage transformation ratio of the DC-DC converter33may be set in advance.

FIG.6is a flowchart illustrating a process of the mobile manipulator1b. S1to S13are the same as the flowchart shown inFIG.2.

In the case where the voltage of the battery21is determined as outside the specific range (NO in S13), the starting control unit13instructs the power multiplexer34to output the voltage of the battery21to the manipulator31(S21). Together with this, the starting control unit13starts the manipulator31(S14).

In the case where the voltage of the battery21is determined as falling within the specific range (YES in S13), the starting control unit13instructs the power multiplexer34to output the voltage obtained by transforming the voltage of the battery21by using the DC-DC converter33to the manipulator31(S22). Together with this, the starting control unit13starts the manipulator31.

Even in the case where the voltage input to the voltage transformation device32, that is, the voltage of the battery21, falls within the specific range, the voltage output by the transformation device32, that is, the voltage input by the manipulator31, is transformed into a voltage not falling within the specific range by the voltage transformation device32. Therefore, the manipulator31can always be started.

[Implementation Example by Software]

The control block of the mobile manipulator1and the mobile manipulator1a(in particular, the voltage acquisition unit11, the condition determination unit12, the starting control unit13, the output control unit14, the input unit15, and the configuration grasping unit16) may be realized by logic circuits (hardware) formed by integrated circuits (IC chips), and may also be realized by software.

In the latter case, the mobile manipulator1and the mobile manipulator1ainclude a computer that executes commands of a program as software that realizes the respective functions. The computer, for example, includes one or more processors, and includes a computer readable recording medium storing the program. In addition, in the computer, the processor reads the program from the recording medium and executes the program, thereby achieving the objective of the invention. As the processor, for example, a central processing unit (CPU) can be used. As the recording medium, a “non-transitory tangible medium”, such as a tape, a disc, a card, a semiconductor memory, a programmable logic circuit, etc., can be used, in addition to a read-only memory (ROM), etc. In addition, a random access memory (RAM), etc., for expanding the program may also be provided. Moreover, the program may also be supplied to the computer via any transmission medium (communication network, broadcast waves, etc.) able to transmit the program. According to an aspect of the invention, the program may be embodied in the form of data signals embedded in carrier waves and embodied through electronic transmission.

[Appendix]

In order to solve the above issue, a mobile robot according to an aspect of the invention is a mobile robot capable of mounting an electric load. The mobile robot includes: a voltage acquisition unit, acquiring a voltage of a battery supplying power to the electric load; a condition determination unit, determining whether the voltage falls within a specific range; and a starting control unit, in a case where the condition determination unit determines that the voltage falls within the specific range, (i) disabling starting of the electric load, or (ii) supplying the voltage of the battery that has been transformed to the electric load to start the electric load. The specific range is a portion of a voltage range in which the electric load is operable.

According to the configuration, at the time of starting the electric load, the battery can be prevented from being damaged by the inrush current of the electric load.

It may also be that, in the case where the condition determination unit determines that the voltage falls within the specific range, the starting control unit disables the starting of the electric load.

It may also be that the mobile robot further includes a traveling device supplied with power from the battery to allow the mobile robot to travel, and the starting control unit allows starting of the traveling device regardless of a determination result of the condition determination unit.

According to the configuration, even if the starting of the electric load is disabled, the traveling device can be operated. Therefore, the mobile robot can still be moved by the traveling device, and by charging or discharging the battery, the starting condition of the electric load can be adjusted.

The mobile robot may further include an output control unit performing notification in the case where the condition determination unit determines that the voltage falls within the specific range.

According to the configuration, in the situation in which the starting of the electric load is disabled, the operator can be notified, and the replacement or charging/discharging of the battery can be urged, so that the electric load can be started.

The mobile robot may further include an input unit receiving an input for changing the specific range.

The mobile robot may further include a configuration grasping unit grasping a system configuration of the mobile robot. In a case where a change of the system configuration is detected, the configuration grasping unit may change the specific range to be suitable for the system configuration.

According to the configuration, the specific range can be changed.

The mobile robot may include a voltage transformation device transforming the voltage from the battery to fall out of the specific range and outputting the voltage. In a case where the voltage falls within the specific range, the starting control unit may supply the voltage that has been transformed by the voltage transformation device to the electric load to start the electric load.

According to the configuration, even if the voltage of the battery falls within the specific range, it is possible that the voltage input to the electric load falls out of the specific range. Therefore, the starting condition of the electric load can be adjusted regardless of the voltage of the battery.

A mobile robot according to an aspect of the invention includes a manipulator as the electric load.

A method for controlling a mobile robot according to an aspect of the invention includes: a voltage acquisition step of acquiring a voltage of a battery supplying power to an electric load mounted in the mobile robot; a condition determination step of determining whether the voltage falls within a specific range; and a starting control step of, in a case where the voltage is determined as falling within the specific range in the condition determination step, (i) disabling starting of the electric load, or (ii) supplying the voltage of the battery that has been transformed to the electric load to start the electric load. The specific range is a portion of a voltage range in which the electric load is operable.

The mobile robot according to various aspects of the invention may be realized by using a computer. In such case, a control program of the mobile robot realizing the mobile robot by operating a computer as the respective units (software components) provided in the mobile robot by using the computer and a computer readable recording medium recording the control program also fall within the scope of the invention.

[Additional Note]

The invention is not limited to the embodiments, and various modifications are possible within the scope indicated in the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments also fall within in the technical scope of the invention.