Working robot

Abstract

The invention provides a work robot capable of smoothly performing work. The work robot includes a work mechanism that performs work, a movement mechanism that moves the work robot, a work motor that drives the work mechanism, a movement motor that drives the movement mechanism, a rechargeable battery that supplies power to the work motor and the movement motor, a voltage detection unit that detects a voltage value of the battery, and a control unit. The control unit is configured so as to be able to execute: a two-stage acquisition process in which the control unit acquires, as a first-stage voltage value, a detection value of the voltage detection unit in a state in which a target motor, which is at least one of the working motor and the moving motor, is operated, and then stops the target motor, as a second-stage voltage value; acquiring, as a second-stage voltage value, a detection value of the voltage detection unit in a state in which the target motor is stopped; and a return determination process in which the control unit determines whether or not to return the work robot to the charging station on the basis of the first-stage voltage value and the second-stage voltage value.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a working robot. Background Art

[0002] Patent document 1 discloses a working robot that performs work while moving autonomously. The working robot includes: a working mechanism that performs work; a moving mechanism that moves the working robot; a working motor that drives the working mechanism; a moving motor that drives the moving mechanism; a battery that can be recharged and supplies power to the working motor and the moving motor; a voltage detection unit that detects the voltage value of the battery; and a control unit. When the detection value of the voltage detection unit is a value below a specified value, the control unit returns the working robot to a charging station. The working robot can charge the battery by returning to the charging station.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-10382 Summary of the invention

[0006] If the timing for returning the working robot to the charging station is too late, the remaining battery power will be exhausted halfway through the working robot's return. If the remaining battery power is exhausted halfway through the working robot's return, the working robot will stop before finally reaching the charging station. In this situation, the battery cannot be recharged without the help of the user, and the working robot cannot be used for work. As a result, the working robot may not be able to be used for work smoothly. On the other hand, if the timing for returning the working robot to the charging station is too early, the working robot will return to the charging station even if the remaining battery power is sufficient to allow the working robot to continue working. As a result, the work performed by the working robot will be frequently interrupted, and the working robot may not be able to be used for work smoothly. In this specification, a technology that can smoothly use a working robot to perform work is provided.

[0007] The working robot disclosed in the present specification works while moving autonomously. The working robot comprises: a working mechanism that works; a moving mechanism that moves the working robot; a working motor that drives the working mechanism; a moving motor that drives the moving mechanism; a battery that can be recharged and supplies power to the working motor and the moving motor; a voltage detection unit that detects the voltage value of the battery; and a control unit. The control unit is configured to be able to perform a two-stage acquisition process and a return determination process, wherein in the two-stage acquisition process, the control unit acquires, for at least one of the working motor and the moving motor, a detection value of the voltage detection unit in a state where the target motor is in motion as a first-stage voltage value, then stops the target motor, and acquires the detection value of the voltage detection unit in a state where the target motor is stopped as a second-stage voltage value, and in the return determination process, the control unit determines whether to return the working robot to a charging station based on the first-stage voltage value and the second-stage voltage value.

[0008] When the motor is in motion, the voltage value of the battery will decrease by a corresponding amount compared to when the motor is stopped due to the internal resistance of the motor. Accordingly, in order to appropriately determine the timing for returning the working robot, it is preferred to obtain the detection value of the voltage detection unit for each motion condition of the motor. According to the above configuration, the control unit of the working robot can obtain the detection value of the voltage detection unit for each motion condition of the motor, so the timing for returning the working robot can be appropriately determined. That is, it is possible to prevent the timing for returning the working robot too late or too early. Accordingly, it is possible to prevent the battery from running out of power in the middle of the working robot's return, and it is possible to prevent the work performed by the working robot from being frequently interrupted. Accordingly, the working robot can be used to perform work smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a diagram showing a usage example of the robot mower 2 according to the first embodiment.

[0010] Figure 2 This is a left side view of the robot lawn mower 2 according to the first embodiment.

[0011] Figure 3 This is a rear view of the robot lawn mower 2 according to the first embodiment.

[0012] Figure 4 This is a schematic diagram of the structure of the robot lawn mower 2 according to the first embodiment.

[0013] Figure 5This is a flowchart of the battery voltage management process executed by the control unit 8 of the robot mower 2 according to the first embodiment.

[0014] Figure 6 This is a flowchart of the battery voltage management process executed by the control unit 8 of the robot mower 2 according to the first embodiment.

[0015] Figure 7 This is a diagram schematically showing a temporal change in the voltage value of the battery 18 when the robot mower 2 according to the first embodiment performs a return determination to return to the charging station 110 without correcting the return threshold value Vre.

[0016] Figure 8 This is a diagram schematically showing a temporal change in the voltage value of the battery 18 when the robot mower 2 according to the first embodiment returns to the charging station 110 in accordance with the battery voltage management process.

[0017] Fig. 9 This is a flowchart of the motor burnout avoidance process executed by the control unit 8 of the robot mower 2 according to the first embodiment.

[0018] Fig.10 This is a schematic diagram of the structure of a robot lawn mower 202 according to the second embodiment.

[0019] Fig.11 1 is a diagram schematically showing a temporal change in the voltage value of the battery 18 when the robot mower 2 according to the modification returns to the charging station 110 in accordance with the battery voltage management process. DETAILED DESCRIPTION

[0020] Hereinafter, representative but non-limiting specific examples of the present invention will be described in detail with reference to the accompanying drawings. This detailed description is intended only to show the details of the preferred examples for implementing the present invention to those skilled in the art, and is not intended to limit the scope of the present invention. In addition, the additional features and inventions disclosed are intended to provide a further improved working robot, and can be used alone or in conjunction with other features or inventions.

[0021] In addition, the combination of features or processes disclosed in the following detailed description is not necessary to practice the invention in the broadest sense, and in particular is only described for the purpose of illustrating representative specific examples of the invention. In addition, the individual features of the following representative specific examples and the individual features described in the claims do not necessarily have to be combined as described below, that is, as described in the specific examples described herein, or in the order listed, to provide additional and useful embodiments of the invention.

[0022] All features described in this specification and / or claims are intended to be disclosed individually and independently of each other as limitations on specific matters disclosed in the initial application and described in the claims, in addition to the features described in the embodiments and / or claims. In addition, all numerical ranges and groupings or group-related records are intended to be disclosed as limitations on specific matters disclosed in the initial application and described in the claims, with the intention of disclosing intermediate structures thereof.

[0023] In one or more embodiments, the control unit can be configured to: obtain the detection value of the voltage detection unit as a first judgment voltage value, execute the two-stage acquisition processing when the first judgment voltage value is a value below a specified value, and not execute the two-stage acquisition processing when the first judgment voltage value exceeds the specified value.

[0024] Obviously, when the voltage value of the battery is high to a certain extent, it is not necessary to perform the two-stage acquisition process, nor is it necessary to return the working robot. When the two-stage acquisition process is performed before the voltage value of the battery is high to a certain extent, the target motor (that is, at least one of the working motor and the moving motor) will be temporarily stopped unnecessarily, so it may not be possible to smoothly use the working robot to work. According to the above configuration, the control unit is configured to not perform the two-stage acquisition process when the voltage value of the battery is high to a certain extent. Accordingly, it is possible to suppress the situation where the target motor is interrupted unnecessarily, so that the working robot can be smoothly used to work.

[0025] In one or more embodiments, the control unit may store a specified return threshold. The control unit may be configured to further perform a threshold correction process for correcting the return threshold based on the first stage voltage value and the second stage voltage value. The return determination process may include the following process, namely, obtaining the detection value of the voltage detection unit as the second determination voltage value, and determining whether to return the working robot to the charging station in accordance with whether the second determination voltage value is a value below the corrected return threshold.

[0026] According to the above configuration, the control unit determines whether to return the working robot to the charging station based not only on the first and second stage voltage values ​​but also on a predetermined return threshold value. This makes it possible to more appropriately determine the timing for returning the working robot to the charging station.

[0027] In one or more embodiments, the control unit can be configured to: obtain the detection value of the voltage detection unit as a third judgment voltage value, and when the third judgment voltage value is a value below the return threshold, perform the two-stage acquisition processing; when the third judgment voltage value exceeds the return threshold, do not perform the two-stage acquisition processing.

[0028] Obviously, when the voltage value of the battery is high to a certain extent, it is not necessary to perform the two-stage acquisition process, nor is it necessary to return the working robot. When the two-stage acquisition process is performed before the voltage value of the battery is high to a certain extent, the target motor (that is, at least one of the working motor and the moving motor) will be temporarily stopped unnecessarily, so it may not be possible to smoothly use the working robot to work. According to the above configuration, the control unit is configured to not perform the two-stage acquisition process when the voltage value of the battery is high to a certain extent. Accordingly, it is possible to suppress the situation where the target motor is interrupted unnecessarily, so that the working robot can be smoothly used to work.

[0029] In one or more embodiments, in the threshold correction process, the control unit may correct the return threshold based on a recovery voltage value obtained by subtracting the first-stage voltage value from the second-stage voltage value.

[0030] According to the above configuration, the return threshold value can be corrected by a simple means.

[0031] In one or more embodiments, in the threshold correction process, the control unit may correct the return threshold by subtracting the restoration voltage value from the return threshold.

[0032] Sometimes the object motor is configured to operate while the working robot is working, and to stop while the working robot is returning to the charging station. In this case, it is foreseeable that when the working robot finishes its work and begins to return, the voltage value of the battery will be restored to the recovery voltage value. Accordingly, it is preferably considered that when determining whether to return the working robot, the voltage value of the battery will be restored to the recovery voltage value. According to the above configuration, it can be considered that when determining whether to return the working robot, the voltage value of the battery will be restored to the recovery voltage value. Therefore, it is possible to appropriately confirm the timing of returning the working robot to the charging station.

[0033] In one or more embodiments, in the threshold correction process, when the recovery voltage value is a value greater than a specified upper limit value, the control unit may subtract the upper limit value from the return threshold instead of subtracting the recovery voltage value from the return threshold.

[0034] In the case where the recovery voltage value calculated in the threshold correction process is large, the recovery amount of the voltage value of the battery at the timing when the working robot finishes the work and starts to return may sometimes be lower than the calculated recovery voltage value. Accordingly, when the recovery voltage value calculated in the threshold correction process is corrected by subtracting the recovery voltage value from the return threshold value before the recovery voltage value calculated in the threshold correction process is large, the voltage value of the battery at the timing when the working robot starts to return may be smaller than expected. As a result, the remaining amount of the battery may be exhausted in the middle of the return of the working robot. According to the above configuration, in the case where the recovery voltage value calculated in the threshold correction process exceeds the upper limit value, the value obtained by subtracting the recovery voltage value from the return threshold value becomes the corrected return threshold value, but the value obtained by subtracting the upper limit value from the return threshold value becomes the corrected return threshold value. Accordingly, it is possible to suppress the situation where the voltage value of the battery at the timing when the working robot starts to return is smaller than expected. Accordingly, it is possible to suppress the situation where the remaining amount of the battery is exhausted in the middle of the return of the working robot.

[0035] In one or more embodiments, in the threshold correction process, when the recovery voltage value is a value below a predetermined lower limit value, the control unit may use the return threshold value before correction as the return threshold value after correction.

[0036] When the two-stage acquisition process and the threshold correction process are executed in a state where the voltage value of the battery is reduced to the vicinity of the return threshold, the calculated recovery voltage value may be small. In this case, even if the object motor (that is, at least one of the working motor and the moving motor) that has stopped in the two-stage acquisition process is operated again to restart the operation of the working robot, the timing for the working robot to start returning immediately will also come. Therefore, the action of the working robot from the restart of the operation to the start of the return is not an action that will change the progress of the operation, and can be considered as an unnecessary action. If the working robot performs unnecessary actions for a long time, the working efficiency of the working robot will be reduced. According to the above-mentioned structure, when the recovery voltage value calculated in the threshold correction process is small, the return threshold after correction becomes: the same value as the return threshold before correction. That is, the return threshold after correction becomes: a value greater than the value obtained by subtracting the recovery voltage value from the return threshold. As a result, the timing for the working robot to start returning will be advanced, so the time for the working robot to perform unnecessary actions can be shortened. Accordingly, the working efficiency of the working robot can be improved.

[0037] In one or more embodiments, one of the working motor and the moving motor may be the target motor. The other of the working motor and the moving motor may be an out-of-target motor that is not the target motor. When the out-of-target motor is stopped, the control unit may perform the two-stage acquisition process.

[0038] The two-stage acquisition process is a process for observing the change in the voltage value of the battery caused by the change in the operating condition of the target motor. However, the voltage value of the battery may also change according to the operating condition of the non-target motor. Therefore, when the operating condition of the non-target motor changes during the execution of the two-stage acquisition process, it may not be possible to accurately observe the change in the voltage value of the battery caused by the change in the operating condition of the target motor. According to the above configuration, since the operating condition of the non-target motor does not change during the execution of the two-stage acquisition process, the change in the voltage value of the battery caused by the change in the operating condition of the target motor can be accurately observed.

[0039] In one or more embodiments, the control unit may execute the return determination process when the non-target motor is stopped.

[0040] When the motion state of the non-target motor is inconsistent between the two-stage acquisition process and the return determination process, it may not be possible to properly determine the timing for returning the working robot to the charging station. According to the above configuration, since the motion state of the non-target motor is consistent between the two-stage acquisition process and the return determination process, it is possible to properly determine the timing for returning the working robot to the charging station.

[0041] In one or more embodiments, the control unit may stop the non-target motor when the non-target motor continues to operate for a predetermined time.

[0042] Preferably, the two-stage acquisition process (or the return determination process) is repeatedly executed at appropriate time intervals until the timing for returning the working robot is determined. However, in a configuration in which the two-stage acquisition process (or the return determination process) is executed when the non-target motor is stopped, the two-stage acquisition process (or the return determination process) cannot be executed while the non-target motor is in motion. According to the above configuration, when the non-target motor is in motion for a predetermined time, the non-target motor is forcibly stopped. Accordingly, the two-stage acquisition process (or the return determination process) can be repeatedly executed at appropriate time intervals.

[0043] In one or more embodiments, the working motor may be the target motor. The moving motor may be the non-target motor.

[0044] It is expected that the working motor operates while the working robot is working and stops while the working robot is returning to the charging station. Therefore, in order to determine the timing of returning the working robot, it is necessary to obtain the voltage value of the battery for each operating condition of the working motor. On the other hand, it is expected that the moving motor basically operates whether the working robot is working or returning to the charging station. Therefore, in order to determine the timing of returning the working robot, it is not necessary to obtain the voltage value of the battery for each operating condition of the moving motor. However, if a configuration is adopted in which the voltage value of the battery is obtained for each operating condition of the moving motor, the processing load of the control unit will increase unnecessarily. According to the above configuration, the voltage value of the battery is obtained for each operating condition of the working motor, and on the other hand, the voltage value of the battery is not obtained for each operating condition of the moving motor. Therefore, the processing load of the control unit can be reduced, and the timing of returning the working robot to the charging station can be appropriately determined.

[0045] In one or more embodiments, the working mechanism may include a mower for mowing the lawn. The working robot may function as a robot lawn mower capable of autonomous movement.

[0046] According to the above configuration, the robot mower can be returned to the charging station at an appropriate timing.

[0047] (Example 1)

[0048] like Figure 1 As shown, the working robot of the present embodiment is, for example, a robot lawn mower 2 used in a field 100 with a lawn. The field 100 is provided with, for example, a house 102, a pond 104, a road 106, and a fence 108. In addition, the field 100 is provided with a charging station 110 connected to an external power source (for example, a commercial power source), and a metal wire 112 defining a working area WA of the robot lawn mower. The working area WA mentioned here refers to an area surrounded by the metal wire 112. The working area WA of the robot lawn mower 2 is divided into a main area MA including the charging station 110, and a sub-area SA not including the charging station 110. The robot lawn mower 2 is capable of detecting the position of the metal wire 112 so as not to be out of the working area WA (in the working area WA) where the robot lawn mower 2 is located. Figure 1 In the example of FIG. 1 , the robot mower 2 autonomously moves in a manner that it escapes from the main area MA. Accordingly, the robot mower 2 can move on the lawn in a manner that it avoids the house 102, the pond 104, the road 106, and the fence 108 while performing the mowing operation.

[0049] like Figure 2 , Figure 3 , Figure 4 As shown, the robot mower 2 includes a robot body 4, a power supply unit 6, a control unit 8, an operation unit 10, a moving unit 12, a working unit 14, and a detection unit 16. The power supply unit 6, the control unit 8, the operation unit 10, the moving unit 12, the working unit 14, and the detection unit 16 are supported by the robot body 4, respectively.

[0050] Figure 4 The power supply unit 6 shown can supply power to various parts of the robot mower 2 via the power supply circuit 26 of the control unit 8. The power supply unit 6 includes: a rechargeable battery 18 such as a lithium ion battery, and a charging interface 20 electrically connected to the battery 18. The nominal capacity of the battery 18 is, for example, 5.0 Ah. The nominal voltage of the battery 18 is, for example, 18 V. The robot mower 2 can be connected to the charging station 110 (see FIG. 1 ) by means of the charging interface 20. Figure 1 ) is connected to the charging station 110. The storage battery 18 can be charged by the power supplied from the charging station 110 when the robot lawn mower 2 is connected to the charging station 110. The charging method of the storage battery 18 can be wired charging. Specifically, the storage battery 18 can be charged in a state where the terminal provided at the charging station 110 and the terminal provided at the charging interface 20 are connected to each other. Alternatively, the charging method of the storage battery 18 can be wireless charging. Specifically, the storage battery 18 can be charged by using the power transmission coil provided at the charging station 110 to generate an induced electromotive force in the power receiving coil provided at the charging interface 20.

[0051] The control unit 8 includes a processor 22, a memory 24, and a power supply circuit 26. The memory 24 includes a ROM, a RAM, etc. The memory 24 stores a program for autonomously controlling the robot lawn mower 2. The processor 22 is configured to autonomously control the robot lawn mower 2 according to the program stored in the memory 24. In addition, the memory 24 stores settings related to the robot lawn mower 2 (for example, the mowing height of the lawn). The settings related to the robot lawn mower 2 also include settings related to the action mode of the robot lawn mower 2. The action mode settings of the robot lawn mower 2 include: including settings related to the main area MA (refer to Figure 1 ) corresponding to the main area corresponding mode, and the sub-area SA (refer to Figure 1 ) any one of multiple modes including the sub-area corresponding mode.

[0052] The operation unit 10 is provided, for example, on the robot body 4 (see Figure 2) and is provided with switches and the like that can be operated by a user. The user can perform various operations related to the robot lawn mower 2 by means of the operation unit 10. The various operations mentioned here refer to, for example, operations for switching on / off the main power supply of the robot lawn mower 2, operations for inputting instructions to the robot lawn mower 2, and operations for changing settings related to the robot lawn mower 2.

[0053] The moving part 12 includes a pair of left and right casters 28L and 28R, a pair of left and right drive wheels 30L and 30R, and a pair of left and right moving motors 32L and 32R. The moving motors 32L and 32R are, for example, brushless DC motors. The drive wheels 30L and 30R are connected to the output shafts of the moving motors 32L and 32R, respectively. Figure 2 , Figure 3 As shown, the robot lawn mower 2 is placed on the ground G with the casters 28L, 28R and the drive wheels 30L, 30R in contact with the ground G. The moving unit 12 is moved by the moving motors 32L, 32R (see Figure 4 ) is operated to rotate the drive wheels 30L and 30R, thereby enabling the robot body 4 to move forward, backward, and turn.

[0054] like Figure 2 As shown, the working unit 14 includes a cutting blade 34 and a working motor 36. The cutting blade 34 is a rotating blade formed in a substantially disk shape. The working motor 36 is, for example, a brushless DC motor. The working motor 36 is supported by the robot body 4 in a state in which the output shaft is tilted from the front to the rear as it moves from the top to the bottom. The cutting blade 34 is connected to the output shaft of the working motor 36. The working unit 14 can mow the lawn by operating the working motor 36 to rotate the cutting blade 34.

[0055] like Figure 4 As shown, the detection unit 16 includes a wire detection sensor 38 , a motor current detection circuit 40 , and a battery voltage detection circuit 42 .

[0056] The metal wire detection sensor 38 is used to detect the metal wire 112 (refer to Figure 1 ) is a sensor for detecting. The metal wire detection sensor 38 is, for example, a magnetic sensor. In this embodiment, from the charging station 110 (refer to Figure 1) applies a predetermined electric signal to the metal wire 112. Accordingly, a magnetic signal corresponding to the predetermined electric signal is generated around the metal wire 112. The metal wire detection sensor 38 is configured to detect the magnetic signal and output it to the processor 22. The processor 22 can grasp the situation that the robot mower 2 is close to the metal wire 112 or the situation that the robot mower 2 is located on the metal wire 112 based on the signal pattern or signal strength of the magnetic signal detected by the metal wire detection sensor 38.

[0057] The motor current detection circuit 40 is configured to detect current values ​​supplied to the movement motors 32L and 32R and the working motor 36 , respectively, and output the detected current values ​​to the processor 22 .

[0058] The battery voltage detection circuit 42 is configured to detect the voltage value of the battery 18 and output the voltage value to the processor 22 . The processor 22 can thereby grasp the voltage value of the battery 18 .

[0059] Hereinafter, the operation or processing executed by the control unit 8 (specifically, the processor 22 ) will be described.

[0060] (Mowing operation)

[0061] Mowing operation: Robotic lawn mower 2 (refer to Figure 1 For example, when the robot lawn mower 2 is powered on, the operation unit 10 (see Figure 4 ) and instructs the start of mowing operation, the mowing operation starts. When the mowing operation starts, the control unit 8 confirms that there is no abnormality in the robot mower 2 and starts the mowing operation using the robot mower 2. That is, the control unit 8 drives the working motor 36 (see Figure 2 ) and the cutting knife 34 (refer to Figure 2 ) is driven by the moving motors 32L and 32R (refer to Figure 4 ) so that the driving wheels 30L, 30R (refer to Figure 2 ) is driven to mow the lawn. During the mowing operation, the control unit 8 sometimes interrupts or ends the mowing operation performed by the robot mower 2 according to the situation and performs other actions. The control unit 8 ends the mowing operation when the specified operation end condition is met. The operation end condition mentioned here includes, for example, that the elapsed time from the start of the mowing operation reaches the time preset by the user.

[0062] (Battery voltage management processing; Figure 5 , Figure 6 )

[0063] In the case of the robot lawn mower 2 (refer to Figure 1 ) is set to the main area corresponding mode, the battery voltage management process is repeatedly executed during the mowing operation described above. The battery voltage management process is: when the voltage value of the battery 18 is low, the robot lawn mower 2 is returned to the charging station 110 (refer to Figure 1 ) to carry out storage battery 18 (refer to Figure 4 ) is charged. In the memory 24 (refer to Figure 4 ) pre-stores: the voltage value of the battery 18 (return threshold value Vre) that should be ensured in order to return the robot mower 2 to the charging station 110. In this embodiment, the return threshold value Vre is set to 17.5V. The battery voltage management process mainly includes: a process of correcting the return threshold value Vre, and a process of returning the robot mower 2 to the charging station 110 based on the corrected return threshold value Vre′.

[0064] like Figure 5 As shown, in S2, the control unit 8 determines whether the correction flag is on. The correction flag is a status register included in the memory 24. If the return threshold value Vre' after correction is not obtained, the correction flag is off. If the correction flag is off (NO), the process proceeds to S4.

[0065] In S4, the control unit 8 determines whether the moving motors 32L and 32R (see Figure 4 ) is stopped. While the robot lawn mower 2 is performing the mowing operation, the moving motors 32L and 32R are basically in motion, but when, for example, the robot lawn mower 2 changes direction, the moving motors 32L and 32R may stop. If the moving motors 32L and 32R are not stopped (in the case of NO), the process proceeds to S6.

[0066] In S6, the control unit 8 determines whether the operation duration of the moving motors 32L and 32R is a time greater than the first upper limit time (for example, 2 minutes). The operation duration of the moving motors 32L and 32R referred to herein refers to the elapsed time from the start of the most recent operation of the moving motors 32L and 32R. When the operation duration of the moving motors 32L and 32R is less than the first upper limit time (in the case of NO), the process returns to S2. When the operation duration of the moving motors 32L and 32R is a time greater than the first upper limit time (in the case of YES), the process proceeds to S8.

[0067] In S8 , the control unit 8 stops the moving motors 32L and 32R.

[0068] If it is determined in S4 that the moving motors 32L and 32R have stopped (in the case of YES), or after S8, the process proceeds to S10. In S10, the control unit 8 obtains the battery voltage detection circuit 42 (refer to Figure 4 ) as the voltage value for determination, and determines whether the obtained voltage value for determination is a value below the return threshold value Vre. In addition, during the lawn mowing operation of the robot lawn mower 2, the operation motor 36 (refer to Figure 4 ) will basically not stop. Accordingly, in S10, the voltage value of the battery 18 under the condition that the working motor 36 is in operation and the moving motors 32L and 32R are stopped is obtained as the determination voltage value. In the case where the determination voltage value exceeds the return threshold value Vre (in the case of NO), the process returns to S2. In addition, after the moving motors 32L and 32R are stopped in S8 and then in the case of NO in S10, the control unit 8 causes the moving motors 32L and 32R to operate again. In the case where the determination voltage value is a value below the return threshold value Vre (in the case of YES), the process enters S12.

[0069] In S12, the control unit 8 acquires the detection value of the battery voltage detection circuit 42 as the first stage voltage value V1. In S12, the voltage value of the battery 18 in the state where the working motor 36 is operating and the moving motors 32L and 32R are stopped is acquired as the first stage voltage value V1. After S12, the process proceeds to S14.

[0070] In S14, the control unit 8 stops the working motor 36 in addition to the moving motors 32L and 32R. That is, the control unit 8 interrupts the mowing operation performed by the robot mower 2. In addition, the control unit 8 waits for a predetermined time (for example, 2 seconds) in a state where the working motor 36 and the moving motors 32L and 32R are stopped. As a result, the voltage value of the battery 18 recovers the voltage drop caused by the internal resistance of the working motor 36 compared to before the mowing operation was interrupted. After S14, the process enters S16.

[0071] In S16, the control unit 8 obtains the detection value of the battery voltage detection circuit 42 as the second stage voltage value V2 in a state where the mowing operation performed by the robot mower 2 is interrupted. In S16, the voltage value of the battery 18 in a state where the working motor 36 and the moving motors 32L and 32R are stopped is obtained as the second stage voltage value V2. In addition, after obtaining the second stage voltage value V2, the control unit 8 operates the moving motors 32L and 32R and the working motor 36 again, and restarts the mowing operation using the robot mower 2. After S16, the process enters S18.

[0072] In S18, the control unit 8 calculates the recovery voltage value Vdiff by subtracting the first stage voltage value V1 from the second stage voltage value V2. Therefore, the recovery voltage value Vdiff = V2 - V1. After S18, the process proceeds to S20.

[0073] In S20, the control unit 8 determines whether the recovery voltage value Vdiff calculated in S18 is less than a predetermined lower limit value (eg, 0.1 V). If the recovery voltage value Vdiff is less than the lower limit value (YES), the process proceeds to S22.

[0074] In S22 , the control unit 8 corrects the recovery voltage value Vdiff to 0V.

[0075] If it is determined in S20 that the recovery voltage value Vdiff is not a value below the lower limit value (in the case of NO), the process proceeds to S24. In S24, the control unit 8 determines whether the recovery voltage value Vdiff calculated in S18 is a value above a prescribed upper limit value (for example, 0.5V). If the recovery voltage value Vdiff is a value below the upper limit value (in the case of YES), the process proceeds to S26.

[0076] In S26 , the control unit 8 corrects the recovery voltage value Vdiff so as to make it the same value as the upper limit value (for example, 0.5 V) used in the determination in S24 .

[0077] In the case where it is determined in S24 that the recovery voltage value Vdiff is not a voltage value below the upper limit value (in the case of NO), after S22, or after S26, the process enters S28. In S28, the control unit 8 corrects the return threshold value Vre by subtracting the recovery voltage value Vdiff from the return threshold value Vre. Therefore, the corrected return threshold value Vre'=Vre-Vdiff. In addition, the control unit 8 stores the corrected return threshold value Vre' in the memory 24 and switches the correction flag to on. After S28, the process returns to S2.

[0078] If it is determined in S2 that the calibration flag is on (in the case of YES), the process proceeds to Figure 6 In S30, the control unit 8 determines whether the moving motors 32L and 32R are stopped. If the moving motors 32L and 32R are not stopped (NO), the process proceeds to S32.

[0079] In S32, the control unit 8 determines whether the operation duration of the moving motors 32L and 32R is longer than the second upper limit time (for example, 1 minute). If the operation duration of the moving motors 32L and 32R is shorter than the second upper limit time (in the case of NO), the process returns to S2 (refer to Figure 5 ). When the operation duration of the moving motors 32L and 32R is equal to or longer than the second upper limit time (in the case of YES), the process proceeds to S34.

[0080] In S34 , the control unit 8 stops the moving motors 32L and 32R.

[0081] In the case where it is determined in S30 that the moving motors 32L and 32R have stopped (in the case of YES), or after S34, the processing enters S36. In S36, the control unit 8 obtains the detection value of the battery voltage detection circuit 42 as the judgment voltage value, and determines whether the obtained judgment voltage value is a value below the corrected return threshold value Vre′. In addition, in S36, the voltage value of the battery 18 under the condition that the working motor 36 is in operation and the moving motors 32L and 32R have stopped is obtained as the judgment voltage value. In the case where the judgment voltage value exceeds the corrected return threshold value Vre′ (in the case of NO), the processing returns to S2 (refer to Figure 5 ). In addition, after the moving motors 32L and 32R are stopped in S34, if S36 is NO, the control unit 8 operates the moving motors 32L and 32R again. If the determination voltage value is a value less than the corrected return threshold value Vre' (if YES), the process proceeds to S38.

[0082] In S38, the control unit 8 ends the mowing operation performed by the robot mower 2 and returns the robot mower 2 to the charging station 110. Specifically, the control unit 8 operates the moving motors 32L and 32R while stopping the operation motor 36, so that the robot mower 2 reaches the charging station 110 along the wire 112. After S38, the process proceeds to S40.

[0083] In S40, the control unit 8 connects the robot mower 2 to the charging station 110 and starts charging the battery 18. In addition, in response to the robot mower 2 being connected to the charging station 110, the control unit 8 deletes the corrected return threshold value Vre′ from the memory 24 and switches the correction flag to off. In addition, it should be noted that even if the robot mower 2 is connected to the charging station 110 regardless of S40 of the battery voltage management process, the corrected return threshold value Vre′ stored in the memory 24 is deleted from the memory 24. Similarly, it should be noted that even if the robot mower 2 is connected to the charging station 110 regardless of S40 of the battery voltage management process, the correction flag is switched to off. After S40, the process enters S42.

[0084] In S42, the control unit 8 determines whether a predetermined normal recovery condition is satisfied. The normal recovery condition includes, for example, that the voltage value of the battery 18 detected by the battery voltage detection circuit 42 is greater than a predetermined value (e.g., 20V). If the normal recovery condition is not satisfied (in the case of NO), the process repeatedly executes S42. If the normal recovery condition is satisfied (in the case of YES), the process proceeds to S44.

[0085] In S44, the control unit 8 ends the charging of the battery 18 and releases the docking between the robot lawn mower 2 and the charging station 110, so that the moving motors 32L, 32R and the working motor 36 start to operate again. That is, the control unit 8 restarts the lawn mowing operation using the robot lawn mower 2. After S44, Figure 5 , Figure 6 The battery voltage management process shown ends.

[0086] (Advantages of battery voltage management processing)

[0087] The robot lawn mower 2 uses the operation motor 36 (see Figure 4 ) to perform the operation, but, upon returning to the charging station 110 (refer to Figure 1 ) during which the working motor 36 is stopped. Accordingly, when the robot lawn mower 2 finishes the lawn mowing operation and starts to return, the battery 18 (see Figure 4 ) will restore the voltage drop caused by the internal resistance of the working motor 36. Figure 7As shown in FIG. 1 , when the voltage value of the battery 18 during the period when the robot lawn mower 2 is performing mowing operation reaches the return threshold value Vre, if the robot lawn mower 2 starts to return, the voltage value of the battery 18 will recover soon and greatly exceed the return threshold value Vre. Therefore, even if the remaining amount of the battery 18 is large enough to allow the robot lawn mower 2 to continue mowing operation, the robot lawn mower 2 will still return to the charging station 110. Accordingly, since the robot lawn mower 2 frequently returns to the charging station 110, the ratio of the time when the robot lawn mower 2 is not performing mowing operation (for example, the time when it returns to the charging station 110 or the time when the battery 18 is charged) to the time when the robot lawn mower 2 is performing mowing operation becomes larger. As a result, the operation efficiency of the robot lawn mower 2 may be reduced.

[0088] like Figure 8 As shown, according to the battery voltage management process, the voltage drop amount caused by the internal resistance of the working motor 36 is determined as the recovery voltage value Vdiff. And, by subtracting the recovery voltage value Vdiff from the predetermined return threshold value Vre, the return threshold value Vre′ is obtained. And, at the timing when the voltage value of the battery 18 during the period when the robot lawn mower 2 performs the mowing operation reaches the return threshold value Vre′, the robot lawn mower 2 starts to return. According to this, the voltage value of the battery 18 immediately after the robot lawn mower 2 starts to return is restored to a value near the return threshold value Vre. Therefore, the robot lawn mower 2 can be returned to the charging station 110 at the timing until the remaining amount of the battery 18 is reduced to the limit at which the robot lawn mower 2 can continue the mowing operation. According to this, the frequency of the robot lawn mower 2 returning to the charging station 110 can be reduced as much as possible, so that the ratio of the time when the robot lawn mower 2 does not perform the mowing operation to the time when the robot lawn mower 2 performs the mowing operation can be reduced. As a result, the working efficiency of the robot lawn mower 2 can be improved.

[0089] (Avoid handling if the motor burns out; Fig. 9 )

[0090] Regardless of the robot lawn mower 2 (refer to Figure 1 ), the motor burnout avoidance process is repeatedly executed during the mowing operation described above. In addition, it should be noted that the motor burnout avoidance process is also executed at the stage of confirming that the robot mower 2 has no abnormality before the robot mower 2 starts mowing.

[0091] In S52, the control unit 8 determines whether the working motor 36 (see Figure 2) is overheated. Overheating as used herein means that the temperature of the working motor 36 reaches an excessively high temperature (for example, a temperature above 150°C), reaches a temperature that causes the working motor 36 to burn out (melts the film of the winding and causes a short circuit), or reaches a temperature that affects the life of the working motor 36. For example, in the motor current detection circuit 40 (refer to Figure 4 ) (i.e., the current supplied to the working motor 36) becomes a value greater than the first current value (e.g., 5A) for a period of time greater than the first duration (e.g., 55 minutes), the control unit 8 estimates that the temperature of the working motor 36 has reached an excessively high temperature, and determines that the working motor 36 is overheated. In addition, even if the detection value of the motor current detection circuit 40 becomes a value greater than the second current value (e.g., 6A) higher than the first current value for a period of time greater than the second duration (e.g., 22 minutes), the control unit 8 determines that the working motor 36 is overheated. In addition, even if the detection value of the motor current detection circuit 40 becomes a value greater than the third current value (e.g., 7A) higher than the second current value for a period of time greater than the third duration (e.g., 10 minutes), the control unit 8 determines that the working motor 36 is overheated. In the case where the working motor 36 is overheated (in the case of YES), the process proceeds to S54.

[0092] In S54, the control unit 8 determines whether the robot mower 2 is in the main area MA (see Figure 1 ). When the operation mode of the robot mower 2 is set to the main area corresponding mode, the control unit 8 determines that the robot mower 2 is in the main area MA (YES). When the operation mode of the robot mower 2 is set to a mode other than the main area corresponding mode, the control unit 8 determines that the robot mower 2 is not in the main area MA (NO). When the robot mower 2 is in the main area MA (YES), the process proceeds to S56.

[0093] In S56, the control unit 8 returns the robot mower 2 to the charging station 110 (see Figure 1 Specifically, the control unit 8 stops the working motor 36 and controls the moving motors 32L and 32R (see Figure 4 ) to make the robot mower 2 reach the charging station 110 along the wire 112. In addition, the control unit 8 activates a light source device or a buzzer (not shown) provided on the robot body 4, thereby notifying by sound or light that an abnormality has occurred. After S56, the process proceeds to S58.

[0094] In S58, the control unit 8 docks the robot mower 2 with the charging station 110 and starts charging the battery 18 (see Figure 4 ) is charged. In addition, the control unit 8 continues to report that an abnormality has occurred even after starting to charge the storage battery 18. After S58, the process proceeds to S60.

[0095] In S60, the control unit 8 determines whether the first abnormal recovery condition is satisfied. The first abnormal recovery condition of the present embodiment includes the condition that the temperature of the working motor 36 is expected to reach a normal temperature (e.g., a temperature below 40°C). For example, the first abnormal recovery condition includes the condition that the battery voltage detection circuit 42 (see Figure 4 ) The voltage value of the battery 18 detected by the control circuit 10 becomes a value above a specified value (for example, 20V). This is because: if the charging of the battery 18 continues to a certain extent, it can be inferred that the temperature of the working motor 36 has dropped to a normal temperature during this period. Alternatively, the first abnormal recovery condition includes: the elapsed time after the working motor 36 is determined to be overheated in the most recently executed S52 reaches a specified time (for example, 20 minutes). When the first abnormal recovery condition is not satisfied (in the case of NO), the processing repeatedly executes S60. When the first abnormal recovery condition is satisfied (in the case of YES), the processing enters S62.

[0096] In S62, the control unit 8 ends the charging of the battery 18, and releases the docking between the robot lawn mower 2 and the charging station 110, and operates the moving motors 32L, 32R and the working motor 36 again. That is, the control unit 8 restarts the lawn mowing operation using the robot lawn mower 2. In addition, the control unit 8 stops the operating light source device or buzzer (not shown) and ends the abnormality notification.

[0097] If it is determined in S54 that the robot mower 2 is not in the main area MA (in the case of NO), the process proceeds to S64. In S64, the control unit 8 stops the working motor 36 and the moving motors 32L and 32R, and makes the robot mower 2 standby at the same place. In addition, the control unit 8 activates the light source device or buzzer (not shown) provided in the robot body 4, thereby notifying that an abnormal situation has occurred through sound or light. After S64, the process proceeds to S66.

[0098] In S66, the control unit 8 determines whether the second abnormal recovery condition is satisfied. The second abnormal recovery condition of the present embodiment includes: the operation motor 36 (see Figure 2) reaches a normal temperature (for example, a temperature below 40°C). For example, the second abnormal recovery condition includes: the elapsed time from the time when the working motor 36 was determined to be overheated in the most recently executed S52 reaches a specified time (for example, 20 minutes). When the second abnormal recovery condition is not met (in the case of NO), the processing repeatedly executes S66. Therefore, during the period when the second abnormal recovery condition is not met, the robot mower 2 continues to wait in place. When the second abnormal recovery condition is met (in the case of YES), the processing enters S68.

[0099] In S68, the control unit 8 ends the standby state and operates the moving motors 32L, 32R and the working motor 36 again. That is, the control unit 8 restarts the lawn mowing operation using the robot lawn mower 2. In addition, the control unit 8 stops the operating light source device or buzzer (not shown) and ends the abnormality notification.

[0100] If it is determined in S52 that the working motor 36 is not overheated (in the case of NO), after S62 or after S68, Fig. 9 The motor burnout avoidance process shown is complete.

[0101] (Example 2)

[0102] like Fig.10 As shown, the working robot of this embodiment is a robot mower 202 having substantially the same components as the robot mower 2 of Embodiment 1. Components common to the robot mower 2 and the robot mower 202 are denoted by common reference numerals and their description is omitted.

[0103] The robot lawn mower 202 replaces the detection unit 16 of the first embodiment (see Figure 4 ) and includes a detection unit 204. The detection unit 204 is different from the detection unit 16 in that it includes a motor temperature sensor 206. The motor temperature sensor 206 is configured to detect the temperature of the working motor 36 and output it to the processor 22 of the control unit 8. The temperature of the working motor 36 mentioned here includes, for example, the temperature of the stator of the working motor 36, the temperature of the Hall sensor provided on the working motor 36, and the temperature of the motor driver substrate that controls the rotation of the working motor 36.

[0104] In this embodiment, the control unit 8 Fig. 9In S52 of the motor burnout avoidance process shown in the figure, when the temperature of the working motor 36 detected by the motor temperature sensor 206 reaches an excessively high temperature (e.g., a temperature of 150° C. or higher), it is determined that the working motor 36 is overheated. In addition, the first abnormal recovery condition used in S60 of the motor burnout avoidance process further includes: the temperature of the working motor 36 detected by the motor temperature sensor 206 reaches a normal temperature (e.g., a temperature of 40° C. or lower). In addition, the second abnormal recovery condition used in S66 of the motor burnout avoidance process further includes: the temperature of the working motor 36 detected by the motor temperature sensor 206 reaches a normal temperature (e.g., a temperature of 40° C. or lower).

[0105] (Variation Example)

[0106] The working robot may be a robot other than the robot lawn mower 2 or 202. For example, the working robot may be a robot vacuum cleaner having a brush and / or a suction mechanism for collecting dust and other garbage. In this case, the working motor 36 may be used as a motor for driving the brush and / or the suction mechanism. In addition, the working robot may be a steel bar bundling robot having a steel bar bundling mechanism for bundling a portion where a plurality of steel bars intersect. In this case, the working motor 36 may also be used as a motor for driving the steel bar bundling mechanism.

[0107] At least one of the working motor 36 and the moving motors 32L and 32R may be a motor other than a brushless DC motor (for example, a brushed DC motor).

[0108] The moving part 12 may include a pair of left and right crawlers instead of the casters 28L and 28R and the driving wheels 30L and 30R. The moving motors 32L and 32R may be used as motors for driving the pair of left and right crawlers.

[0109] The battery 18 may be a rechargeable battery 18 other than a lithium-ion battery (e.g., a nickel-metal hydride battery or a nickel-cadmium battery). In addition, the nominal capacity and nominal voltage of the battery 18 may be appropriately changed. The nominal capacity of the battery 18 may be, for example, 3.0 Ah. The nominal voltage of the battery 18 may be, for example, 36 V.

[0110] The setting of the return threshold value Vre may be changed as appropriate. The user may be able to change the setting of the return threshold value Vre via the operation unit 10 , or the user may be unable to change the setting of the return threshold value Vre via the operation unit 10 .

[0111] The control unit 8 can Figure 5 , Figure 6In the battery voltage management process shown, after S8, S10 is skipped and S12 is executed. That is, the control unit 8 may be configured to execute the processes after S12 regardless of the remaining charge of the battery 18 after S8.

[0112] The control unit 8 may use a threshold value Vth (for example, Vth=17.6V) different from the return threshold value Vre in the determination process of S10 of the battery voltage management process. That is, in S10, the control unit 8 may obtain the detection value of the battery voltage detection circuit 42 as the determination voltage value, and determine whether the obtained determination voltage value is a value below the threshold value Vth. In this example, Fig.11 As shown, the voltage drop amount caused by the internal resistance of the working motor 36 is also determined as the recovery voltage value Vdiff. As a result, the return threshold value Vre' is obtained in a substantially similar manner to the embodiment, so that the voltage value of the battery 18 immediately after the robot mower 2, 202 starts to return is restored to a value near the return threshold value Vre. Therefore, the robot mower 2, 202 can be returned to the charging station 110 while the remaining amount of the battery 18 is appropriately retained.

[0113] The control unit 8 can Figure 5 , Figure 6 In the battery voltage management process shown, after S20 is judged as NO, S24 is skipped and S28 is executed. As a result, it is possible to allow the recovery voltage value Vdiff to exceed the upper limit value. Alternatively, the control unit 8 may skip S20 and execute S24 after S18. As a result, it is possible to allow the recovery voltage value Vdiff to become a value below the lower limit value (a value greater than 0). Alternatively, after S18, S20, S22, S24, and S26 may be skipped and S28 may be executed. As a result, it is possible to allow both the recovery voltage value Vdiff to exceed the upper limit value and the recovery voltage value Vdiff to become a value below the lower limit value (a value greater than 0).

[0114] The control unit 8 can correct the return threshold value Vre by subtracting a value obtained by multiplying the recovery voltage value Vdiff by a predetermined coefficient k (for example, k=0.8) from the return threshold value Vre in S28 of the battery voltage management process. Therefore, it can be configured as: Vre′=Vre−k×Vdiff.

[0115] The control unit 8 may determine whether to return the robot mower 2 to the charging station 110 without calculating the recovery voltage value Vdiff and correcting the return threshold value Vre in the battery voltage management process. For example, the control unit 8 may determine whether the detection value (determination voltage value) of the battery voltage detection circuit 42 is less than 2×V1-V2 after obtaining the first stage voltage value V1 in S12 and the second stage voltage value V2 in S16. The control unit 8 may execute the processes after S38 when the determination voltage value is less than 2×V1-V2 (in the case of YES). The control unit 8 may restart the battery voltage management process from the beginning when the determination voltage value exceeds 2×V1-V2 (in the case of NO). In this example, the correction flag may always be disconnected.

[0116] In the battery voltage management process, the control unit 8 may skip S4, S6, and S8 and execute S10 after determining NO in S2. As a result, the process after S10 may be executed when the moving motors 32L and 32R are not stopped (that is, when the moving motors 32L and 32R are operating). However, it is preferable that the operating state (operation / stop) of the moving motors 32L and 32R is not switched during the execution of S10, S12, S14, and S16.

[0117] In the battery voltage management process, the control unit 8 may skip S30, S32, and S34 and execute S36 after a YES determination in S2. As a result, the process after S36 is executed when the moving motors 32L and 32R are not stopped (that is, when the moving motors 32L and 32R are operating).

[0118] In the first and second embodiments, the control unit 8 is configured to stop the working motor 36 in the state of being in motion in S12, S14, and S16 of the battery voltage management process, and observe the change in the voltage value of the battery 18. That is, the working motor 36 is the target motor mentioned in this specification, and the moving motors 32L and 32R are the non-target motors mentioned in this specification. In other embodiments, the control unit 8 may be configured to stop the working motor 36 in the state of being in motion and the moving motors 32L and 32R in S12, S14, and S16, and observe the change in the voltage value of the battery 18. That is, both the working motor 36 and the moving motors 32L and 32R may be the target motors. In addition, in other embodiments, the control unit 8 may also be configured to stop the moving motors 32L and 32R in the state of being in motion in S12, S14, and S16, and observe the change in the voltage value of the battery 18. That is, the moving motors 32L and 32R may be target motors, and the working motor 36 may be a non-target motor.

[0119] The control unit 8 can Fig. 9 In the motor burnout avoidance process shown, after charging of the battery 18 is started in S58, the motor burnout avoidance process is terminated instead of executing the processes after S60, and the mowing operation being executed is terminated. Then, the control unit 8 may terminate the charging of the battery 18, for example, corresponding to the battery 18 being fully charged, and the robot mower 2, 202 may be placed on standby at the charging station 110. That is, the control unit 8 may be configured so that the robot mower 2, 202 does not automatically resume the mowing operation after an abnormality (overheating of the working motor 36) occurs.

[0120] The detection unit 16, 204 can be configured to detect not only the overheating of the working motor 36, but also various abnormalities related to the working unit 14. The abnormalities related to the working unit 14 mentioned here include, for example, excessive loads being applied to the working motor 36, or the cutter 34 being consumed to the extent that it needs to be replaced. The control unit 8 can execute the processing after S54 of the motor burnout avoidance processing when the abnormality related to the working unit 14 is detected by the detection unit 16, 204. Accordingly, when an abnormality related to the working unit 14 occurs, the user can be notified of the abnormality, or the robot mower 2, 202 can be returned to the charging station 110, or the robot mower 2, 202 can be placed on standby at the original location.

[0121] The first abnormal recovery condition (or the second abnormal recovery condition) may include: the detection value of the motor current detection circuit 40 (that is, the current supplied to the working motor 36) being a value below a specified current value continues for a period of time longer than a specified time.

[0122] The operation mode of the robot lawn mower 2, 202 can be changed automatically regardless of the user's operation. For example, the control unit 8 can use GPS to determine the work area WA where the robot lawn mower 2, 202 performs mowing operations, and change the operation mode of the robot lawn mower 2, 202 to a mode corresponding to the determined work area WA. Alternatively, the control unit 8 can pre-store mapping information of the work area WA, and determine the work area WA where the robot lawn mower 2, 202 performs mowing operations based on the mapping information.

[0123] The detection unit 16, 204 may be configured to detect various abnormalities in addition to the above-mentioned abnormalities. For example, the detection unit 16, 204 may be configured to detect a situation where the robot body 4 falls over or is picked up by someone. When the above-mentioned abnormality is detected by the detection unit 16, 204, the control unit 8 may use a buzzer (not shown) provided on the robot body 4 to notify the user that an abnormality has occurred.

[0124] (Characteristics of Embodiment)

[0125] In one or more embodiments, the robot lawn mower 2, 202 (an example of a working robot) performs work while moving autonomously. The robot lawn mower 2, 202 includes: a cutting blade 34 (an example of a working mechanism) that performs work; driving wheels 30L, 30R (an example of a moving mechanism) that moves the robot lawn mower 2, 202; a working motor 36 that drives the cutting blade 34; moving motors 32L, 32R that drive the driving wheels 30L, 30R; a battery 18 that is rechargeable and supplies power to the working motor 36 and the moving motors 32L, 32R; a battery voltage detection circuit 42 (an example of a voltage detection unit) that detects the voltage value of the battery 18; and a control unit. The control unit 8 is configured to be capable of performing a two-stage acquisition process (see Figure 5 S12, S14, S16) and return determination processing (refer to Figure 6 S36), wherein in the above-mentioned two-stage acquisition processing, the control unit 8 obtains the detection value of the battery voltage detection circuit 42 when the working motor 36 is in operation as the first-stage voltage value V1 for the working motor 36 (an example of the object motor), and then stops the working motor 36, and obtains the detection value of the battery voltage detection circuit 42 when the working motor 36 is stopped as the second-stage voltage value V2. In the above-mentioned return determination processing, the control unit 8 determines whether to return the robot lawn mower 2, 202 to the charging station 110 based on the first-stage voltage value V1 and the second-stage voltage value V2.

[0126] When the working motor 36 is in motion, the voltage value of the battery 18 is lowered by a corresponding amount due to the internal resistance of the working motor 36 compared to when the working motor 36 is stopped. Accordingly, in order to appropriately determine the timing for returning the robot mower 2, 202, it is preferable to obtain the detection value of the battery voltage detection circuit 42 for each motion condition of the working motor 36. According to the above configuration, since the control unit 8 of the robot mower 2, 202 can obtain the detection value of the battery voltage detection circuit 42 for each motion condition of the working motor 36, the timing for returning the robot mower 2, 202 can be appropriately determined. That is, it is possible to prevent the timing for returning the robot mower 2, 202 from being too late or too early. Accordingly, it is possible to prevent the remaining amount of the battery 18 from being exhausted in the middle of returning the robot mower 2, 202, and it is possible to prevent the work performed by the robot mower 2, 202 from being frequently interrupted. This allows smooth operation using the robot mowers 2 and 202 .

[0127] In one or more embodiments, the control unit 8 is configured to obtain the detection value of the battery voltage detection circuit 42 as the (first) judgment voltage value, and when the (first) judgment voltage value is a value below the return threshold value Vre (or, threshold value Vth) (an example of a specified value), perform a two-stage acquisition process, and when the (first) judgment voltage value exceeds the return threshold value Vre (or, threshold value Vth), do not perform the two-stage acquisition process.

[0128] Obviously, when the detection value of the battery voltage detection circuit 42 is high to a certain extent, it is not necessary to perform the two-stage acquisition process, and it is not necessary to return the robot mower 2, 202. When the two-stage acquisition process is performed before the voltage value of the battery 18 is high to a certain extent, the working motor 36 is temporarily stopped unnecessarily, so it may not be possible to smoothly use the robot mower 2, 202 to work. According to the above configuration, the control unit 8 is configured to not perform the two-stage acquisition process when the voltage value of the battery 18 is high to a certain extent. According to this, it is possible to suppress the situation where the working motor 36 is interrupted unnecessarily, so that the robot mower 2, 202 can be used to work smoothly.

[0129] In one or more embodiments, the control unit 8 stores a predetermined return threshold value Vre. The control unit 8 is configured to further perform a threshold correction process for correcting the return threshold value Vre based on the first stage voltage value V1 and the second stage voltage value V2 (see Figure 5 The return determination process includes: obtaining the detection value of the battery voltage detection circuit 42 as the (second) determination voltage value, and determining whether to return the robot lawn mower 2, 202 to the charging station 110 in accordance with whether the (second) determination voltage value is a value below the corrected return threshold value Vre′ (see Figure 6 S36).

[0130] According to the above configuration, the control unit 8 determines whether to return the robot mower 2, 202 to the charging station 110 based not only on the first stage voltage value V1 and the second stage voltage value V2 but also on the predetermined return threshold value Vre. This makes it possible to more appropriately determine the timing for returning the robot mower 2, 202 to the charging station 110.

[0131] In one or more embodiments, the control unit 8 is configured to obtain the detection value of the battery voltage detection circuit 42 as the (3rd) judgment voltage value, and when the (3rd) judgment voltage value is a value below the return threshold value Vre, perform a two-stage acquisition process, and when the (3rd) judgment voltage value exceeds the return threshold value Vre, do not perform the two-stage acquisition process.

[0132] Obviously, when the detection value of the battery voltage detection circuit 42 is high to a certain extent, it is not necessary to perform the two-stage acquisition process, and it is not necessary to return the robot mower 2, 202. When the two-stage acquisition process is performed before the voltage value of the battery 18 is high to a certain extent, the working motor 36 is temporarily stopped unnecessarily, so it may not be possible to smoothly use the robot mower 2, 202 to work. According to the above configuration, the control unit 8 is configured to not perform the two-stage acquisition process when the voltage value of the battery 18 is high to a certain extent. According to this, it is possible to suppress the situation where the working motor 36 is interrupted unnecessarily, so that the robot mower 2, 202 can be used to work smoothly.

[0133] In one or more embodiments, in the threshold correction process, the control unit 8 corrects the return threshold value Vre based on the restoration voltage value Vdiff obtained by subtracting the first stage voltage value V1 from the second stage voltage value V2.

[0134] According to the above configuration, the return threshold value Vre can be corrected by simple means.

[0135] In one or more embodiments, in the threshold correction process, the control unit 8 corrects the return threshold value Vre by subtracting the restoration voltage value Vdiff from the return threshold value Vre.

[0136] The working motor 36 is sometimes configured to operate while the robot mower 2, 202 is working, and to stop while the robot mower 2, 202 is returning to the charging station 110. In this case, it can be expected that when the robot mower 2, 202 finishes the work and starts to return, the voltage value of the battery 18 will be restored to the recovery voltage value Vdiff. Based on this, it is preferably considered that when determining whether to return the robot mower 2, 202, the voltage value of the battery 18 will be restored to the recovery voltage value Vdiff. According to the above configuration, it can be considered that when determining whether to return the robot mower 2, 202, the voltage value of the battery 18 will be restored to the recovery voltage value Vdiff. Therefore, it is possible to appropriately confirm the timing of returning the robot mower 2, 202 to the charging station 110.

[0137] In one or more embodiments, in the threshold correction process, when the recovery voltage value Vdiff is greater than a specified upper limit value (e.g., 0.5V), the control unit 8 subtracts the upper limit value from the return threshold value Vre instead of subtracting the recovery voltage value Vdiff from the return threshold value Vre.

[0138] When the restoration voltage value Vdiff calculated in the threshold correction process is large, the amount of restoration of the voltage value of the battery 18 at the timing when the robot mower 2, 202 finishes the work and starts to return may be lower than the calculated restoration voltage value Vdiff. Accordingly, when the restoration voltage value Vdiff is subtracted from the return threshold value Vre before the restoration voltage value Vdiff calculated in the threshold correction process is large, the voltage value of the battery 18 at the timing when the robot mower 2, 202 starts to return may be smaller than expected. As a result, the remaining amount of the battery 18 may be exhausted in the middle of the return of the robot mower 2, 202. According to the above configuration, when the restoration voltage value Vdiff calculated in the threshold correction process exceeds the upper limit value, the value obtained by subtracting the restoration voltage value Vdiff from the return threshold value Vre becomes the corrected return threshold value Vre′, instead of the value obtained by subtracting the upper limit value from the return threshold value Vre. This can prevent the voltage value of the battery 18 from being lower than expected when the robot mower 2 or 202 starts to return. This can prevent the battery 18 from running out of power while the robot mower 2 or 202 is returning.

[0139] In one or more embodiments, in the threshold correction process, when the restoration voltage value Vdiff is equal to or less than a predetermined lower limit value (eg, 0.1 V), the control unit 8 uses the return threshold value Vre before correction as the return threshold value Vre′ after correction.

[0140] When the two-stage acquisition process and the threshold correction process are executed in a state where the voltage value of the battery 18 is reduced to the vicinity of the return threshold value Vre, the calculated recovery voltage value Vdiff may be small. In this case, even if the working motor 36 that has stopped in the two-stage acquisition process is activated again and the robot mower 2, 202 is restarted, the timing for the robot mower 2, 202 to start returning will come immediately. Therefore, the action of the robot mower 2, 202 from the restart of the work to the start of the return is not an action that will change the progress of the work, and can be considered as an unnecessary action. If the robot mower 2, 202 performs unnecessary actions for a long time, the working efficiency of the robot mower 2, 202 will be reduced. According to the above configuration, when the recovery voltage value Vdiff calculated in the threshold correction process is small, the return threshold value Vre′ after correction becomes: the same value as the return threshold value Vre before correction. That is, the corrected return threshold value Vre′ becomes a value greater than the value obtained by subtracting the recovery voltage value Vdiff from the return threshold value Vre. As a result, the timing when the robot lawn mower 2, 202 starts to return is advanced, so the time for the robot lawn mower 2, 202 to perform unnecessary actions can be shortened. Accordingly, the operating efficiency of the robot lawn mower 2, 202 can be improved.

[0141] In one or more embodiments, when the movement motors 32L and 32R (examples of non-target motors) are stopped, the control unit 8 executes the two-stage acquisition process.

[0142] The two-stage acquisition process is a process for observing the change in the voltage value of the battery 18 caused by the change in the operating state of the working motor 36. However, the voltage value of the battery 18 may also change according to the operating state of the moving motors 32L and 32R. Therefore, when the operating state of the moving motors 32L and 32R changes during the execution of the two-stage acquisition process, it may not be possible to accurately observe the change in the voltage value of the battery 18 caused by the change in the operating state of the working motor 36. According to the above configuration, the operating state of the moving motors 32L and 32R does not change during the execution of the two-stage acquisition process, so the change in the voltage value of the battery 18 caused by the change in the operating state of the working motor 36 can be accurately observed.

[0143] In one or more embodiments, the control unit 8 executes the return determination process when the movement motors 32L and 32R are stopped.

[0144] If the operating conditions of the moving motors 32L and 32R are inconsistent between the two-stage acquisition process and the return determination process, it may not be possible to appropriately determine the timing for returning the robot mower 2 and 202 to the charging station 110. According to the above configuration, since the operating conditions of the moving motors 32L and 32R are consistent between the two-stage acquisition process and the return determination process, the timing for returning the robot mower 2 and 202 to the charging station 110 can be appropriately determined.

[0145] In one or more embodiments, when the moving motors 32L and 32R continue to operate for a predetermined time (for example, 2 seconds), the control unit 8 stops the moving motors 32L and 32R.

[0146] Preferably, the two-stage acquisition process (or the return determination process) is repeatedly executed at appropriate time intervals until the timing for returning the robot lawn mower 2, 202 is determined. However, in the configuration in which the two-stage acquisition process (or the return determination process) is executed when the moving motors 32L, 32R are stopped, the two-stage acquisition process (or the return determination process) cannot be executed while the moving motors 32L, 32R are in motion. According to the above configuration, when the moving motors 32L, 32R are in motion for a predetermined time, the moving motors 32L, 32R are forcibly stopped. Accordingly, the two-stage acquisition process (or the return determination process) can be repeatedly executed at appropriate time intervals.

[0147] In one or more embodiments, the working motor 36 is a target motor, and the moving motors 32L and 32R are non-target motors.

[0148] It is expected that the working motor 36 operates while the robot mower 2, 202 is operating, and stops while the robot mower 2, 202 is returning to the charging station 110. Therefore, in order to determine the timing for returning the robot mower 2, 202, it is necessary to obtain the voltage value of the battery 18 for each operating state of the working motor 36. On the other hand, it is expected that the moving motors 32L, 32R basically operate regardless of whether the robot mower 2, 202 is operating or returning to the charging station 110. Therefore, in order to determine the timing for returning the robot mower 2, 202, it is not necessary to obtain the voltage value of the battery 18 for each operating state of the moving motors 32L, 32R. However, if a configuration is adopted in which the voltage value of the battery 18 is obtained for each operating state of the moving motors 32L, 32R, the processing load of the control unit 8 is unnecessarily increased. According to the above configuration, the voltage value of the battery 18 is acquired for each operation state of the working motor 36, while the voltage value of the battery 18 is not acquired for each operation state of the moving motors 32L and 32R. Therefore, the processing load of the control unit 8 can be reduced, and the timing for returning the robot mower 2 and 202 to the charging station 110 can be appropriately determined.

[0149] In one or more embodiments, the working mechanism includes a mowing blade 34 for mowing the lawn. The working robot functions as a robot lawn mower 2, 202 capable of autonomous movement.

[0150] According to the above configuration, the robot mower 2 , 202 can be returned to the charging station 110 at an appropriate timing.

Claims

1. A working robot capable of performing work while moving autonomously, characterized in that: The working robot has: an operating organization, which performs the operation; A moving mechanism that enables the working robot to move; A working motor, which drives the working mechanism; A moving motor, which drives the moving mechanism; a storage battery that is rechargeable and supplies power to the working motor and the moving motor; a voltage detection unit configured to detect a voltage value of the battery; and Control Department, The control unit is configured to be capable of executing a two-stage acquisition process and a return determination process. Among them, in the two-stage acquisition processing, the control unit obtains the detection value of the voltage detection unit when the object motor is in action as the first stage voltage value for at least one of the working motor and the moving motor, that is, the object motor, and then stops the object motor and obtains the detection value of the voltage detection unit when the object motor is stopped as the second stage voltage value. In the return determination process, the control unit determines whether to return the working robot to a charging station based on the first-stage voltage value and the second-stage voltage value.

2. The working robot according to claim 1, characterized in that: The control unit is configured to obtain the detection value of the voltage detection unit as a first judgment voltage value, and when the first judgment voltage value is a value below a specified value, perform the two-stage acquisition process, and when the first judgment voltage value exceeds the specified value, not perform the two-stage acquisition process.

3. The working robot according to claim 1, characterized in that: The control unit stores a predetermined return threshold value. The control unit is configured to further execute a threshold correction process for correcting the return threshold based on the first stage voltage value and the second stage voltage value. The return determination process includes: acquiring the detection value of the voltage detection unit as a second determination voltage value, and determining whether to return the working robot to the charging station according to whether the second determination voltage value is a value equal to or lower than the corrected return threshold value.

4. The working robot according to claim 3, characterized in that: The control unit is configured to obtain the detection value of the voltage detection unit as a third judgment voltage value, and when the third judgment voltage value is a value below the return threshold, perform the two-stage acquisition process, and when the third judgment voltage value exceeds the return threshold, not perform the two-stage acquisition process.

5. The working robot according to claim 3 or 4, characterized in that: In the threshold correction process, the control unit corrects the return threshold based on a recovery voltage value obtained by subtracting the first-stage voltage value from the second-stage voltage value.

6. The working robot according to claim 5, characterized in that: In the threshold correction process, the control unit corrects the return threshold by subtracting the restoration voltage value from the return threshold.

7. The working robot according to claim 6, characterized in that: In the threshold correction process, when the restoration voltage value is equal to or greater than a predetermined upper limit value, the control unit subtracts the upper limit value from the return threshold value instead of subtracting the restoration voltage value from the return threshold value.

8. The working robot according to any one of claims 5 to 7, characterized in that: In the threshold correction process, when the restoration voltage value is a value equal to or less than a predetermined lower limit value, the control unit sets the return threshold value before correction as the return threshold value after correction.

9. The working robot according to any one of claims 1 to 8, characterized in that: One of the working motor and the moving motor is the target motor, The other of the working motor and the moving motor is an out-of-target motor that is not the target motor. The control unit executes the two-stage acquisition process when the non-target motor is stopped.

10. The working robot according to claim 9, characterized in that: The control unit executes the return determination process when the non-target motor is stopped.

11. The working robot according to claim 9 or 10, characterized in that: The control unit stops the non-target motor when the non-target motor continues to operate for a predetermined time.

12. The working robot according to any one of claims 9 to 11, characterized in that: The working motor is the target motor, and the moving motor is the non-target motor.

13. The working robot according to any one of claims 1 to 12, characterized in that: The working mechanism comprises: a cutting knife for mowing the lawn, The working robot functions as a robot lawn mower capable of autonomous movement.

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