Electrical Equipment

Abstract

To suppress a current flowing to a diode in an electric apparatus comprising a power supply circuit which receives power supply from a plurality of battery packs via the diode.SOLUTION: An electric apparatus comprises: a first power supply circuit which receives power supply from a first battery pack or a second battery pack via a first discharge path or a second discharge path when a first switch or a second switch is in an ON state; and a second power supply circuit which receives power supply from the first battery pack and the second battery pack via a first rectifier and a second rectifier. The second power supply circuit generates a power supply voltage of a power supply control circuit which controls ON / OFF states of the first switch and the second switch.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electrical device that can accommodate multiple battery packs. [Background technology]

[0002] Patent document 1 discloses an electric transport vehicle that has multiple battery mounting sections to which battery packs can be attached, and is configured so that power is supplied to a power supply circuit from the battery packs attached to each battery mounting section via a diode.

[0003] In this electric vehicle, the power supply circuit generates a power supply voltage for operating a control device that controls the motor that powers the electric vehicle and the lighting device, and the generated power supply voltage is supplied to the control device and its peripheral devices. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6864488 Summary of the Invention [Problem to be solved by the invention]

[0005] In electrical equipment such as the electric transport vehicle, where the power supply circuit receives power from multiple battery packs via diodes, the power supply circuit can continue to operate even if one of the battery packs becomes unable to supply power due to discharge, etc. Furthermore, the diodes provided for each battery pack can prevent current from flowing from one battery pack to another.

[0006] In this type of electrical equipment, the amount of power consumed by the power supply circuit increases as the number of controlled objects by the control circuit increases, and the current flowing through the diode also increases accordingly. When the current flowing through the diode increases, the diode generates heat, causing deterioration or failure. Potential solutions to reduce the heat generated by the diode include increasing its size or providing a cooling fan. However, these solutions increase the size of the power supply circuit and the electrical equipment, leading to increased costs.

[0007] An object of one aspect of the present disclosure is to make it possible to suppress current flowing through diodes in an electrical device including a power supply circuit that receives power from multiple battery packs via diodes. [Means for solving the problem]

[0008] An electrical device according to one aspect of the present disclosure includes a drive circuit, a first battery mounting section, a first discharge path, a second battery mounting section, a second discharge path, a connection point, a first switch, a second switch, a drive control circuit, and a first power supply circuit.

[0009] The drive circuit is configured to drive a controlled object, and the drive control circuit is configured to control the driving of the controlled object by the drive circuit. The first battery mounting portion is configured to allow the first battery pack to be mounted thereon, and the first discharge path is configured to supply DC power from the first battery pack mounted on the first battery mounting portion to the drive circuit.

[0010] In addition, the second battery mounting section is configured to allow a second battery pack to be mounted thereon, and the second discharge path is configured to supply DC power from the second battery pack mounted on the second battery mounting section to the drive circuit.

[0011] In addition, the connection point is a connection point common to each discharge path, where the first discharge path and the second discharge path are connected to each other on the opposite side of the first battery pack and the second battery pack, and the DC power is supplied from the first discharge path and the second discharge path to the drive circuit.

[0012] The first switch is provided in the first discharge path and configured to make the first discharge path conductive / interruptible, and the second switch is provided in the second discharge path and configured to make the second discharge path conductive / interruptible.

[0013] Therefore, when the first switch or the second switch is in the on state, DC power is supplied to the drive circuit from the first battery pack or the second battery pack via the first discharge path or the second discharge path.

[0014] Furthermore, similar to the drive circuit, when the first switch or the second switch is in the on state, the first power supply circuit is supplied with DC power from the first battery pack or the second battery pack via the first discharge path or the second discharge path.

[0015] The first power supply circuit generates a power supply voltage for the drive control circuit using DC power supplied from the first battery pack or the second battery pack, and supplies the power supply voltage to the drive control circuit. Therefore, when the first switch or the second switch is in the on state, the drive circuit and the first power supply circuit operate by receiving power directly from the first battery pack or the second battery pack.

[0016] In addition, since the drive control circuit is supplied with the power supply voltage generated by the first power supply circuit, the drive control circuit also operates when the first switch or the second switch is in the on state, and controls the driving of the controlled object by the drive circuit.

[0017] Next, an electric device according to an aspect of the present disclosure further includes a power supply control circuit, a second power supply circuit, a first power supply path, a first rectifying element, a second power supply path, and a second rectifying element. The power supply control circuit is configured to control the on / off states of the first switch and the second switch, and the second power supply circuit is configured to generate a power supply voltage for the power supply control circuit and supply it to the power supply control circuit.

[0018] The first power supply path is configured to supply DC power from the first battery pack attached to the first battery attachment portion to the second power supply circuit. A first rectifier element is provided on the first power supply path. The first rectifier element allows current to flow from the first battery pack to the second power supply circuit and prevents current from flowing from the second power supply circuit to the first battery pack.

[0019] The second power supply path is configured to supply DC power from the second battery pack mounted in the second battery mounting portion to the second power supply circuit. A second rectifier element is provided on the second power supply path. The second rectifier element allows current to flow from the second battery pack to the second power supply circuit and prevents current from flowing from the second power supply circuit to the second battery pack.

[0020] Therefore, when a battery pack is attached to at least one of the first battery mounting section and the second battery mounting section, DC power is supplied to the second power supply circuit from the battery pack via the first rectifier element and the second rectifier element, and the second power supply circuit generates a power supply voltage for the power supply control circuit using the supplied DC power and supplies it to the power supply control circuit.

[0021] In this way, the electrical device of the present disclosure is provided with two power supply circuits: a first power supply circuit and a second power supply circuit. When the first switch or the second switch is in an on state, the first power supply circuit receives power from the first battery pack or the second battery pack, and generates a power supply voltage for the drive control circuit.

[0022] The first power supply circuit generates the power supply voltage for the drive control circuit, so as the number of drive circuits that drive the controlled object increases, the current that flows through the first discharge path and the second discharge path increases. However, when the first switch or the second switch is in the on state, each of these discharge paths is made conductive, and power is supplied from the first battery pack or the second battery pack to the first power supply circuit and the drive circuit.

[0023] Therefore, even if the discharge current flowing through each discharge path becomes large, the voltage drop (in other words, power consumption) occurring in the first switch or the second switch does not become large, and the first switch or the second switch does not generate heat and deteriorate or break down.

[0024] On the other hand, the second power supply circuit is supplied with power from the first battery pack and the second battery pack via the first rectifier element and the second rectifier element. Therefore, when the power consumption of the second power supply circuit increases, the current flowing through the first power supply path and the second power supply path via the first rectifier element and the second rectifier element increases.

[0025] However, since the second power supply circuit generates the power supply voltage to be supplied to the power supply control circuit that switches the on / off states of the first switch and the second switch, the power consumption of the second power supply circuit does not change depending on the number of drive circuits or the operation of the drive control circuit, and the current flowing through the first rectifier element and the second rectifier element does not increase, causing the first rectifier element and the second rectifier element to generate heat.

[0026] Therefore, according to the electric device of the present disclosure, there is no need to increase the size of the first rectifying element and the second rectifying element or to provide a cooling fan in order to reduce the amount of heat generated by the first rectifying element and the second rectifying element, which prevents the device from becoming larger and leading to increased costs due to measures to prevent heat generation by the first rectifying element and the second rectifying element. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a perspective view illustrating an appearance of a robot dust collector according to an embodiment. [Figure 2] FIG. 2 is a plan view of the robot dust collector of FIG. 1 as seen from the back side. [Figure 3] FIG. 2 is a block diagram showing a circuit configuration of the robot dust collector. [Figure 4] 10 is a flowchart showing a discharge battery switching control process executed by a power supply management MCU. [Figure 5] 5 is a flowchart showing the SWA2 fault diagnosis process shown in FIG. 4. [Figure 6] 5 is a flowchart illustrating the discharge battery switching process shown in FIG. 4. [Figure 7] 10 is a time chart showing the changes in the on / off state of each switch that is switched in the discharging battery switching process. [Figure 8] 10 is a flowchart showing a discharge battery switching control process according to a fourth modification. [Figure 9] 10 is a flowchart showing a discharging battery switching process according to a fourth modification. [Figure 10] 10 is a flowchart showing the SWB2 fault diagnosis process of Modification 4. DETAILED DESCRIPTION OF THE INVENTION

[0028] [Summary of the embodiment] In an embodiment, the electric device of the present disclosure may further include a third rectifying element, a third switch, a fourth rectifying element, and a fourth switch in addition to the above-described configuration.

[0029] The third rectifier element may be provided in series on the first discharge path between the first battery pack and the connection point and configured to block current from flowing from the connection point to the first battery pack. The third switch may be connected in parallel to the third rectifier element and configured to connect / disconnect both ends of the third rectifier element.

[0030] The fourth rectifier element may be provided in series on the second discharge path between the second battery pack and the connection point and configured to block current from flowing from the connection point to the second battery pack. The fourth switch may be connected in parallel to the fourth rectifier element and configured to connect / disconnect both ends of the fourth rectifier element.

[0031] In this way, when the electrical device of the present disclosure is provided with the third rectifier element, the third switch, the fourth rectifier element, and the fourth switch, it becomes possible to prevent current from flowing from one battery pack to the other battery pack.

[0032] That is, for example, when the discharge path for supplying power to the first power supply circuit and the drive circuit is switched from the first discharge path to the second discharge path or vice versa, it is necessary to ensure that the power supply to the first power supply circuit and the drive circuit is not interrupted.

[0033] To achieve this, the first switch and the second switch can be temporarily turned on simultaneously when switching the discharge path. However, this results in the two battery packs being directly connected in parallel, which causes current to flow from the battery pack that will be used for discharging to the battery pack that has been used for discharging until now.

[0034] In other words, the discharge path is switched by the power supply control circuit when the amount of power (hereinafter referred to as the remaining capacity) stored in one of the battery packs used to supply power to the first power supply circuit and the drive circuit decreases. Therefore, when the discharge path is switched, the remaining capacity of the battery pack that has been used until now will be lower than the remaining capacity of the battery pack that will be used next.

[0035] In this state, if the first switch and the second switch are turned on simultaneously, charging current will flow from the battery pack with the larger remaining capacity to the battery pack with the smaller remaining capacity, causing deterioration or failure of the battery packs due to uncontrolled charging current.

[0036] In contrast, if the first discharge path and the second discharge path are provided with a third rectifying element and a fourth rectifying element, respectively, it is possible to prevent current from flowing from a battery pack with a large remaining capacity to a battery pack with a small remaining capacity.

[0037] However, simply providing the third rectifier element and the fourth rectifier element in each discharge path will cause current to continue to flow in the forward direction through the third rectifier element or the fourth rectifier element when power is supplied to the first power supply circuit and the drive circuit.

[0038] However, by connecting the third switch and the fourth switch in parallel to the third rectifier element and the fourth rectifier element as described above, it is possible to make current flow through the third rectifier element or the fourth rectifier element only when the discharge path is switched.

[0039] Specifically, only when the discharge path is switched, the third switch or the fourth switch is turned off, causing the third rectifier element or the fourth rectifier element to function as an interrupt element for the charging current. As a result, when power is supplied to the first power supply circuit and the drive circuit, current is prevented from flowing through the third rectifier element or the fourth rectifier element, and heat generation and deterioration or failure of the third rectifier element or the fourth rectifier element can be prevented.

[0040] Additionally / alternatively, the power supply control circuit may be configured to control the on / off states of the first and third switches so that the first and third switches are on and the second and fourth switches are off, in which case the power source for the drive circuit and the first power supply circuit is the first battery pack.

[0041] In this state, when a stop condition for stopping the power supply from the first battery pack is met, the power supply control circuit may invert the on / off states of the third switch and the second switch in that order, and then invert the on / off states of the first switch and the fourth switch. In this way, the power supply source to the drive circuit and the first power supply circuit can be switched from the first battery pack to the second battery pack.

[0042] In this case, the power supply control circuit inverts the on / off states of the third switch and then the second switch, so that the second switch is switched to the on state after the third switch has been switched to the off state.

[0043] Therefore, in this state, although the first discharge path and the second discharge path are conductive, the third switch is in the off state, and therefore the charging current flowing from the second battery pack to the first battery pack is blocked by the third rectifier element.

[0044] When the first discharge path and the second discharge path are thus connected, the power supply control circuit switches the first switch to the off state and switches the fourth switch to the on state, thereby interrupting the first discharge path and supplying power to the drive circuit and the first power supply circuit from the second discharge path, while also preventing a discharge current from flowing through the fourth rectifier element.

[0045] In this case, the on / off states of the first switch and the fourth switch may be switched simultaneously, or may be switched in the order of the first switch and then the fourth switch, or the fourth switch and then the first switch.

[0046] Additionally / alternatively, when a parallel circuit of the third switch and the third rectifier element is provided in the first discharge path, a voltage detection circuit may be further provided.The power supply control circuit may be configured to detect a voltage across the third switch via the voltage detection circuit when the first switch is in an on state and the third switch is in an off state, and determine whether the third switch or the third rectifier element has failed.

[0047] In other words, when the first switch is in an on state and the third switch is in an off state, a current flows through the first discharge path via the first switch and the third rectifier element, and a forward current flows through the third rectifier element, causing a voltage drop.

[0048] Therefore, if the voltage across the third switch detected by the voltage detection circuit is a voltage corresponding to the voltage drop across the third rectifier element, it can be determined that the third switch and the third rectifier element are normal.

[0049] Furthermore, if the voltage across the third switch detected by the voltage detection circuit is not a voltage corresponding to the voltage drop across the third rectifier element, it can be determined that the third switch or the third rectifier element is faulty.

[0050] Therefore, when the power supply control circuit determines that the third switch or the third rectifier element has failed as described above, an abnormality has occurred in the first discharge path, and therefore the power supply control circuit may be configured to limit the control of the controlled object by the drive circuit.

[0051] Additionally / alternatively, the power supply control circuit may be configured to determine whether or not there is a fault in the third switch or the third rectifying element before switching the power supply to the drive circuit and the first power supply circuit from the first battery pack to the second battery pack.

[0052] Additionally / alternatively, the power supply control circuit may be further configured to determine whether there is a failure in the fourth switch or the fourth rectifier element. In this case, the power supply control circuit determines whether there is a failure in the fourth switch or the fourth rectifier element when the second switch is in the on state and the fourth switch is in the off state when switching the power supply to the drive circuit and the first power supply circuit from the first battery pack to the second battery pack.

[0053] Similar to the fault determination of the third switch or third rectifier element, the fault determination of the fourth switch or fourth rectifier element is performed by detecting the voltage across the fourth switch via a voltage detection circuit to determine whether the fourth switch or fourth rectifier element has failed.

[0054] Furthermore, when it is determined that the fourth switch or the fourth rectifier element has failed, the power supply control circuit may be configured to limit the control of the controlled object by the drive circuit because an abnormality has occurred in the second discharge path.

[0055] Additionally or alternatively, the third rectifying element and the third switch, and the fourth rectifying element and the fourth switch may each be in the form of a FET having a body diode. Additionally / alternatively, the first switch and the second switch may each be in the form of a FET having a body diode, in which case the body diode of the FET constituting the first switch and the second switch may be configured to block current from flowing from the first battery pack and the second battery pack to the connection point, respectively.

[0056] Specific Exemplary Embodiments Exemplary embodiments of the present disclosure will be described below in conjunction with the drawings. In this embodiment, a robot dust collector 1 that collects dust while autonomously traveling on a floor surface to be cleaned will be described as an example of an electrical device that can be equipped with a plurality of battery packs.

[0057] <Overall configuration of the robot dust collector> As shown in Figures 1 and 2, the robot dust collector 1 includes a main body 2, a bumper 3, a battery mounting section 4, a suction fan 5, casters 7, rollers 8, a running device 12, a main brush 13, side brushes 15, and a handle 17.

[0058] The main body 2 has a top surface 2A, a bottom surface 2B facing the floor, and a side surface 2C connecting the peripheral edge of the top surface 2A with the peripheral edge of the bottom surface 2B. The outer shape of the main body 2 is substantially circular in a plane parallel to the top surface 2A.

[0059] The main body 2 includes a housing 11 having an internal space, and its bottom surface 2B is provided with a rectangular suction port 18 that is long in the left-right direction. The suction port 18 is for sucking in dust from the floor surface and is provided at the front of the bottom surface 2B.

[0060] The bumper 3 is supported by the main body 2 so as to be movable while facing the front part of the side surface 2C of the main body 2. Therefore, when the robotic dust collector 1 collides with an object present around the main body 2, the bumper 3 moves relative to the main body 2, thereby mitigating the impact acting on the main body 2.

[0061] The battery mounting section 4 is capable of detachably mounting the battery pack 30. The battery mounting section 4 is provided with a terminal for receiving power supply from the mounted battery pack 30.

[0062] The battery mounting sections 4 are provided in two locations on the rear of the main body 2. Therefore, the robot dust collector 1 can operate by receiving power from the battery packs 30 mounted in each battery mounting section 4.

[0063] The battery pack 30 has a built-in rechargeable battery BT (see FIG. 3). The battery BT is, for example, a lithium-ion battery. When the battery pack 30 is attached to the battery attachment section 4, the battery BT is electrically connected to the terminals of the battery attachment section 4, and power is supplied from the battery BT to the robot dust collector 1. The battery pack 30 can also be used as a power source for electrical equipment other than the robot dust collector 1, such as a power tool.

[0064] In the following description, when distinguishing between the two battery mounting sections 4, one will be referred to as the first battery mounting section 4A and the other as the second battery mounting section 4B. The battery pack 30 mounted in the first battery mounting section 4A will be referred to as the first battery pack 30A, and the battery pack 30 mounted in the second battery mounting section 4B will be referred to as the second battery pack 30B.

[0065] The suction fan 5 is disposed in the internal space of the housing 11. A suction motor 32 (see FIG. 3) that generates power to rotate the suction fan 5 is provided in the internal space of the housing 11. Therefore, when the suction motor 32 is driven, the suction fan 5 rotates, and the rotation of the suction fan 5 generates a suction force at the suction port 18 to suck in dust.

[0066] The casters 7 and rollers 8 are rotatably provided on the bottom surface 2B of the main body 2, and movably support the main body 2. Two casters 7 are provided at the rear of the bottom surface 2B, and one roller 8 is provided at the front of the bottom surface 2B.

[0067] The traveling device 12 includes wheels 9 rotatably mounted on the bottom surface 2B of the main body 2. Two wheels 9 are arranged on the left and right sides at the center of the bottom surface 2B in the front-to-rear direction. Each of the two wheels 9 is fixed to a rotation axis X0 along a line dividing the bottom surface 2B into the front and rear, and rotates around the rotation axis X0.

[0068] The wheels 9 partially protrude downward from the bottom surface 2B of the main body 2. Therefore, the outer circumferential surfaces of the wheels 9 come into contact with the floor surface, and the wheels 9 rotate to move the main body 2 back and forth. A wheel motor 34 (see FIG. 3) that generates power to rotate the wheel 9 is provided for each wheel 9 in the internal space of the housing 11. Therefore, when the wheel motor 34 is driven, the wheel 9 rotates, and the robot dust collector 1 moves autonomously.

[0069] The wheel motors 34 can change the rotation direction for each wheel 9 and can drive each wheel 9 with a different drive amount. Therefore, the robot dust collector 1 turns when each wheel 9 is driven with a different drive amount by the corresponding wheel motor 34.

[0070] Main brush 13 is disposed at suction port 18 so as to face the floor surface. Main brush 13 is supported by main body 2 so as to be rotatable around a rotation axis extending in the left-right direction of suction port 18. Furthermore, at least a portion of main brush 13 protrudes downward from bottom surface 2B of main body 2, and comes into contact with the floor surface when wheels 9 are placed on the floor surface.

[0071] A brush motor 36 (see FIG. 3) that generates power to rotate the main brush 13 is provided in the internal space of the housing 11. Therefore, when the brush motor 36 is driven, the main brush 13 rotates, and as the main brush 13 rotates, dust on the floor surface is stirred up and sucked in through the suction port 18.

[0072] The side brushes 15 are arranged at the front of the bottom surface 2B of the main body 2 so as to face the floor surface. Two side brushes 15 are arranged, one on the left and one on the right. The side brushes 15 each have a disk-shaped disc member 15A and multiple brushes 15B provided around the disc member 15A.

[0073] The disk member 15A is rotatable around a rotation axis that is disposed along the up-down direction of the main body 2. The plurality of brushes 15B are provided on the disk member 15A such that some of the brushes 15B protrude outward from the side surface 2C of the main body 2. The plurality of brushes 15B are also provided around the periphery of the disk member 15A such that at least some of the brushes 15B come into contact with the floor surface.

[0074] The interior space of the housing 11 is also provided with brush motors 36 that rotate the rotation shafts of the two side brushes 15. Therefore, each side brush 15 rotates when the corresponding brush motor 36 is driven, and as each side brush 15 rotates, dust present on the floor surface around the main body 2 moves to the suction port 18.

[0075] The handle 17 is provided on the top surface 2A of the main body 2 at the front of the housing 11. Both ends of the handle 17 are rotatably connected to the housing 11. Therefore, a user of the robot dust collector 1 can grasp the handle 17, lift the robot dust collector 1, and carry the robot dust collector 1.

[0076] Next, the main body 2 of the robot dust collector 1 is provided with an interface device 20, an obstacle sensor 22, and a detection device 24. Also provided within the housing 11 is a control device 50 (see FIG. 3) that is connected to these components and drives and controls the suction motor 32, wheel motor 34, and brush motor 36.

[0077] The interface device 20 is provided at the rear of the top surface 2A of the main body 2, and has a plurality of operation units that are operated by the user of the robot dust collector 1. The interface device 20 is provided with operation units such as a main power switch 20A and a remaining capacity display switch 20B. The interface device 20 also has a display unit 20C for displaying the remaining capacity of the battery pack 30, etc.

[0078] The remaining capacity display switch 20B is disposed in two locations corresponding to the first battery mounting section 4A and the second battery mounting section 4B. When one of the remaining capacity display switches 20B is operated, the remaining capacity of the battery pack 30A or 30B mounted in the battery mounting section 4A or 4B corresponding to the operated remaining capacity display switch 20B is displayed on the display section 20C.

[0079] The obstacle sensor 22 detects, without contact, objects that exist in at least a portion of the periphery of the robotic dust collector 1. The obstacle sensor 22 includes an ultrasonic sensor that emits ultrasonic waves into the surrounding area and detects objects from the reflected waves. A plurality of obstacle sensors 22 are provided at intervals on the side surface 2C of the main body 2.

[0080] The detection device 24 is provided on the top surface 2A of the main body 2, further rearward than the interface device 20. The detection device 24 includes an optical sensor 24A that rotates around a rotation axis X1 that is disposed along the up-down direction of the main body 2, and a cover member 24B that covers and protects at least a portion of the optical sensor 24A.

[0081] The optical sensor 24A emits detection light to non-contactly detect objects around the main body 2. The optical sensor 24A includes a laser sensor that emits laser light and receives the reflected wave to detect an object.

[0082] The detection device 24 emits radar light to almost the entire area around the main body 2 at a predetermined height position above the main body 2 by rotating the optical sensor 24A around the rotation axis X1, and detects objects present in the surrounding area and the distance to the objects.

[0083] The optical sensor 24A may include an infrared sensor that detects an object by emitting infrared light, or a radar sensor that detects an object by emitting radio waves. The control device 50 controls the wheel motors 34 to prevent the main body 2 or the bumper 3 from coming into contact with an object based on detection data of surrounding objects by the obstacle sensors 22 and the detection device 24, and causes the robot dust collector 1 to travel autonomously. When the main body 2 or the bumper 3 comes into contact with an object, the control device 50 changes the direction of travel of the traveling device 12 or stops traveling.

[0084] When the control device 50 controls the wheel motor 34 to cause the robot dust collector 1 to travel autonomously, it controls the suction motor 32 and the brush motor 36 to rotate the suction fan 5, the main brush 13, and the side brush 15.

[0085] As a result, dust present on the floor surface is collected at suction port 18 and sucked in through suction port 18. The dust sucked in through suction port 18 is collected in a filter (not shown) that is detachably provided in the internal space of housing 11. Therefore, robot dust collector 1 can automatically clean the floor surface to be cleaned.

[0086] <Control device configuration 1> As shown in FIG. 3, the control device 50 includes drive circuits 52, 54, 56 for the suction motor 32, wheel motor 34, and brush motor 36, a suction motor control circuit 62, a wheel motor control circuit 64, and a brush motor control circuit 66.

[0087] The suction motor control circuit 62, the wheel motor control circuit 64, and the brush motor control circuit 66 are control circuits that drive and control the suction motor 32, the wheel motor 34, and the brush motor 36 via the drive circuits 52, 54, and 56, respectively.

[0088] As described above, the wheel motor 34 is provided for each of the left and right wheels 9, and the brush motor 36 is provided for each of the main brush 13 and the two side brushes 15. For this reason, although not shown in Figure 3, two drive circuits 54 and two wheel motor control circuits 64 are provided for each wheel motor 34. In addition, three drive circuits 56 and three brush motor control circuits 66 are provided, one for each main brush 13 and two side brushes 15.

[0089] The control device 50 also includes a centralized control MCU 70 that centrally manages the motor control by the motor control circuits 62, 64, 66, a regulator 72 that generates the power supply voltage Vdd that operates these, and a power supply control unit 74. MCU is an abbreviation for microcontroller unit that includes a CPU, ROM, RAM, etc., and a power supply management MCU 80, which will be described later, has a similar configuration.

[0090] The centralized control MCU 70 calculates the target rotation speeds of the motors 32, 34, and 36 based on object detection data from the obstacle sensors 22 and the detection device 24, and outputs the calculated target rotation speeds to the corresponding motor control circuits 62, 64, and 66. As a result, the traveling speed, traveling direction, and suction force of the robot dust collector 1 are appropriately controlled.

[0091] The power supply control unit 74 receives DC power from the first battery pack 30A or the second battery pack 30B via the first discharge path LA1 or the second discharge path LB1, and supplies the DC power to the regulator 72.

[0092] The regulator 72 generates a power supply voltage (constant DC voltage) Vdd using DC power supplied from the power supply control unit 74 to operate the centralized control MCU 70 and its peripheral circuits, and the motor control circuits 62, 64, and 66.

[0093] In this embodiment, the centralized control MCU 70 and the motor control circuits 62, 64, 66 correspond to an example of a drive control circuit of the present disclosure, and the regulator 72 and power supply control unit 74 correspond to an example of a first power supply circuit of the present disclosure.

[0094] One end of the first discharge path LA1 is connected to the positive electrode of the battery BT in the first battery pack 30A, and takes in DC power from the first battery pack 30A and supplies it to the power supply control unit 74 and the drive circuits 52, 54, 56.

[0095] One end of the second discharge path LB1 is connected to the positive electrode of the battery BT in the second battery pack 30B, and takes in DC power from the second battery pack 30B and supplies it to the power supply control unit 74 and the drive circuits 52, 54, 56.

[0096] The first discharge path LA1 and the second discharge path LB1 are connected to each other on the opposite side of the first battery pack 30A and the second battery pack 30B. DC power is supplied to the power supply control unit 74 and each of the drive circuits 52, 54, 56 from a connection point PX common to the connected discharge paths.

[0097] A first switch SWA1 configured to connect / disconnect the first discharge path LA1 is provided on a first discharge path LA1 between the first battery pack 30A and the connection point PX, and a second switch SWB1 configured to connect / disconnect the second discharge path LB1 is provided on a second discharge path LB1 between the second battery pack 30B and the connection point PX.

[0098] The first switch SWA1 and the second switch SWB1 each include semiconductor switches Q1 and Q2, each including an n-channel MOSFET, and body diodes D1 and D2, which are formed during the MOSFET manufacturing process.

[0099] The semiconductor switches Q1 and Q2 are arranged on the respective discharge paths LA1 and LB1 so that their drains are on the positive electrodes of the battery packs 30A and 30B and their sources are on the junction PX side. Therefore, the cathodes of the body diodes D1 and D2 are on the positive electrodes of the battery packs 30A and 30B and their anodes are on the junction PX side. Therefore, when the semiconductor switches Q1 and Q2 are in the off state, no current flows from the battery packs 30A and 30B to the junction PX side through the body diodes D1 and D2.

[0100] The first switch SWA1 and the second switch SWB1 are each switched between on and off by the power management MCU 80. When the first switch SWA1 and the second switch SWB1 are in the off state, they electrically cut off the first discharge path LA1 and the second discharge path LB1, respectively.

[0101] Note that "electrically cut off" does not only mean that no current flows in the first and second discharge paths LA1 and LB1, but also includes a leakage current flowing via an internal FET or the like when the first and second switches SWA1 and SWB1 are in the off state. This also applies to the third and fourth switches SWA2 and SWB2 described below.

[0102] The power supply management MCU 80 sets one of the first switch SWA1 and the second switch SWB1 to an ON state and the other to an OFF state, thereby setting the power supply path to the load to one of the first discharge path LA1 and the second discharge path LB1. The power supply management MCU 80 corresponds to an example of a power supply control circuit of the present disclosure.

[0103] Next, the control device 50 is provided with a regulator 82 and a power supply control unit 84 as a second power supply circuit of the present disclosure, in addition to the regulator 72 and the power supply control unit 74 as a first power supply circuit of the present disclosure.

[0104] The power supply control unit 84 receives DC power from the first battery pack 30A and the second battery pack 30B via the first power supply path LA2 and the second power supply path LB2, and supplies the DC power to the regulator 82.

[0105] The regulator 82 generates a power supply voltage (constant DC voltage) Vcc for operating the power management MCU 80 and its peripheral circuits using DC power supplied from the power control unit 84. An example of the peripheral circuits of the power management MCU 80 is the display unit 20C of the interface device 20.

[0106] One end of the first power supply path LA2 is connected to the positive electrode of the battery BT in the first battery pack 30A, and supplies DC power from the first battery pack 30A to the power supply control unit 84. A first rectifying element is provided in the first power supply path LA2 to allow current to flow from the first battery pack 30A to the power supply control unit 84 side and to prevent current from flowing from the power supply control unit 84 side to the first battery pack 30A.

[0107] In this embodiment, the first rectifier element includes a series circuit of two diodes DA1 and DA2. These two diodes DA1 and DA2 are arranged in series on the first power supply path LA2 with the anode on the first battery pack 30A side and the cathode on the power supply control unit 84 side.

[0108] Similarly, the second power supply path LB2 is provided with a second rectifying element that allows current to flow from the second battery pack 30B to the power supply control unit 84 side and prevents current from flowing from the power supply control unit 84 side to the second battery pack 30B.

[0109] Like the first rectifier element, the second rectifier element also includes a series circuit of two diodes DB1 and DB2. That is, the diodes DB1 and DB2 are arranged in series on the second power supply path LB2 so that the second battery pack 30B side is the anode and the power supply control unit 84 side is the cathode.

[0110] That is, the first battery pack 30A and the second battery pack 30B are connected to the power supply control unit 84 by a so-called diode OR. This makes it possible to prevent current from flowing back from the power supply control unit 84 to the first battery pack 30A or the second battery pack 30B.

[0111] Therefore, it is possible to prevent current from flowing from the first battery pack 30A to the second battery pack 30B or in the reverse direction via the first power supply path LA2 and the second power supply path LB2.

[0112] <Effect 1> As described above, in this embodiment, only the power supply control unit 84 receives power supply from the first battery pack 30A and the second battery pack 30B via the diodes DA1, DA2 and DB1, DB2.

[0113] That is, power is supplied to the power supply control unit 74 from the first battery pack 30A or the second battery pack 30B via the first discharge path LA1 and the first switch SWA1 or the second discharge path LB1 and the second switch SWB1.

[0114] Therefore, according to this embodiment, it is possible to suppress the current flowing from each of the battery packs 30A, 30B to the first power supply path LA2 and the second power supply path LB2 via the backflow prevention diodes DA1, DA2 and DB1, DB2.

[0115] Therefore, according to this embodiment, it is possible to prevent the diodes DA1, DA2 and DB1, DB2 provided in the first power supply path LA2 and the second power supply path LB2 from generating heat and causing deterioration or failure.

[0116] Therefore, there is no need to increase the size of the diodes DA1, DA2 and DB1, DB2 or to provide a cooling fan to prevent heat generation from occurring in these diodes, which prevents the device from becoming larger and leading to increased costs.

[0117] <Control device configuration 2> Next, in the control device 50, a third switch SWA2 and a fourth switch SWB2 are provided in series on the first discharge path LA1 and the second discharge path LB1, respectively, closer to the connection point PX than the first switch SWA1 and the second switch SWB1.

[0118] The third switch SWA2 and the fourth switch SWB2 are provided with semiconductor switches Q3 and Q4 including n-channel MOSFETs, similar to the first switch SWA1 and the second switch SWB1.

[0119] The semiconductor switches Q3 and Q4 are provided with body diodes D3 and D4 that are generated during the MOSFET manufacturing process, and the body diodes D3 and D4 are arranged as the third and fourth rectifier elements of the present disclosure.

[0120] That is, the semiconductor switches Q3 and Q4 are arranged on the respective discharge paths LA1 and LB1 so that their drains are on the connection point PX side and their sources are on the first switch SWA1 or second switch SWB1 side.

[0121] For this reason, the body diodes D3 and D4 are arranged so that their cathodes are on the connection point PX side and their anodes are on the first switch SWA1 or second switch SWB1 side. Therefore, the body diodes D3 and D4 function as a third rectifier element and a fourth rectifier element that prevent current from flowing from the connection point PX side to the first switch SWA1 or the second switch SWB1 side.

[0122] The third switch SWA2 and the fourth switch SWB2 are switched between on and off states by the power management MCU 80, similar to the first switch SWA1 and the second switch SWB1. The power management MCU 80 turns on the third switch SWA2 when turning on the first switch SWA1 to supply power from the first battery pack 30A via the first discharge path LA1 to a load such as the power supply control unit 74. In this state, power is supplied with low loss from the first battery pack 30A via the first discharge path LA1 to a load such as the power supply control unit 74.

[0123] Furthermore, the power management MCU 80 turns on the fourth switch SWB2 when turning on the second switch SWB1 to supply power from the second battery pack 30B via the second discharge path LB1 to a load such as the power supply control unit 74. In this state, power is supplied with low loss from the second battery pack 30B via the second discharge path LB1 to a load such as the power supply control unit 74.

[0124] In addition, when the power supply path to a load such as the power supply control unit 74 is switched from the first discharge path LA1 to the second discharge path LB1, the power supply management MCU 80 simultaneously turns on the first switch SWA1 and the second switch SWB1.

[0125] This is to prevent a momentary interruption in the power supply when the power supply path is switched. Note that the first switch SWA1 and the second switch SWB1 are turned on simultaneously when the power supply path is switched from the second discharge path LB1 to the first discharge path LA1.

[0126] However, if the third switch SWA2 and the fourth switch SWB2 are also turned on at the same time when switching the power supply path, a current will flow from the second battery pack 30B to the first battery pack 30A or in the opposite direction.

[0127] For this reason, when switching the power supply path, the power management MCU 80 first turns off both the third switch SWA2 and the fourth switch SWB2. As a result, the body diodes D3 and D4 can prevent current from flowing from the connection point PX to the first switch SWA1 or the second switch SWB1.

[0128] Then, after turning off both the third switch SWA2 and the fourth switch SWB2 in this way, the power management MCU 80 switches the on / off states of the first switch SWA1 and the second switch SWB1 as described above.

[0129] Furthermore, when the power management MCU 80 switches the on / off states of the first switch SWA1 and the second switch SWB1, it turns on the third switch SWA2 or the fourth switch SWB2 on the discharge path selected as the power supply path.

[0130] This is because if the third switch SWA2 and the fourth switch SWB2 are kept in the off state after the power supply path is switched to the first discharge path LA1 or the second discharge path LB1, a load current flows through the body diode D3 or D4.

[0131] That is, if a load current continues to flow through the body diode D3 or D4, the body diode D3 or D4 generates heat, causing the third switch SWA2 and the fourth switch SWB2 to deteriorate or break down.

[0132] Therefore, when the switching of the power supply path is completed, the third switch SWA2 or the fourth switch SWB2 on the discharge path selected as the power supply path is turned on to prevent the body diode D3 or D4 from generating heat.

[0133] Next, the control device 50 is provided with three voltage detection units 86, 88, and 90. Of these, the voltage detection units 86 and 88 detect the voltages of the first discharge path LA1 and the second discharge path LB1, respectively, and input the detected voltage values ​​to the power supply management MCU 80.

[0134] In response to this, the power management MCU 80 acquires from the voltage detection unit 86 or 88 the voltage value of the first discharge path LA1 or the second discharge path LB1 selected as the power supply path. In addition, the power management MCU 80 determines whether the first switch SWA1 or the second switch SWB1 is faulty before supplying power to a load such as the power control unit 74 via the first discharge path LA1 or the second discharge path LB1.

[0135] Specifically, before power is supplied to a load such as the power supply control unit 74, the first switch SWA1 or the second switch SWB1 is in the off state, so no power is supplied to the first discharge path LA1 or the second discharge path LB1, and the voltage value detected by the voltage detection unit 86 or 88 is zero.

[0136] However, if the first switch SWA1 or the second switch SWB1 has a short-circuit fault, the voltage value detected by the voltage detection unit 86 or 88 is not zero, but a voltage value corresponding to the output voltage of the first battery pack 30A or the second battery pack 30B is detected.

[0137] Therefore, when the first switch SWA1 or the second switch SWB1 is in the off state, the power management MCU 80 determines that the first switch SWA1 or the second switch SWB1 has failed if the voltage value detected by the voltage detection unit 86 or 88 is not zero. If the power management MCU 80 determines that the first switch SWA1 or the second switch SWB1 has failed, it does not supply power to loads such as the power control unit 74, and notifies the user of the failure using the interface device 20.

[0138] On the other hand, the voltage detection unit 90 is for detecting the voltages across the third switch SWA2 and the fourth switch SWB2, more specifically, the voltages across the body diodes D3 and D4. The voltage detection unit 90 is in the form of a differential amplifier using, for example, an operational amplifier, and detects the voltages across the body diodes D3 and D4. The detected voltages across the body diodes D3 and D4 are used by the power supply management MCU 80 to detect a failure in the third switch SWA2 or the fourth switch SWB2.

[0139] Of the two input terminals of the voltage detection unit 90, the first input terminal is connected to the discharge path between the power supply control unit 74 and the third switch SWA2 and the fourth switch SWB2. A second input terminal of the voltage detection unit 90 is connected to a first discharge path LA1 between the first switch SWA1 and the third switch SWA2 via the detection switch SWa.

[0140] The second input terminal of the voltage detection unit 90 is also connected to a second discharge path LB1 between the second switch SWB1 and the fourth switch SWB2 via the detection switch SWb. The detection switches SWa and SWb are used to turn on and off the connection between the second input terminal of the voltage detection unit 90 and the first discharge path LA1 or the second discharge path LB1. Each of the detection switches SWa and SWb includes a series circuit of two semiconductor switches.

[0141] These two semiconductor switches are p-channel MOSFETs, and their drains are connected together, so their body diodes are connected together at their anodes.

[0142] Therefore, when the two semiconductor switches of the detection switches SWa and SWb are in the off state, the connection between the second input terminal of the voltage detection unit 90 and the first discharge path LA1 or the second discharge path LB1 can be more reliably cut off.

[0143] The power supply management MCU 80 turns on the detection switch SWa or SWb when detecting the voltage across the body diode D3 or D4 via the voltage detection unit 90. As a result, the voltage across the body diode D3 or D4 is applied between the two input terminals of the voltage detection unit 90, and the voltage detection unit 90 outputs a detection voltage corresponding to the voltage across the body diode D3 or D4.

[0144] The control device 50 is also provided with an application switch SWc for applying the power supply voltage Vcc. This application switch SWc is used to determine whether or not the third switch SWA2 or the fourth switch SWB2 has failed, using the voltage detection unit 86 or 88, before supplying power to a load such as the power supply control unit 74 via the first discharge path LA1 or the second discharge path LB1.

[0145] The application switch SWc includes a semiconductor switch Q5 including a p-channel MOSFET, the source of which is applied with the power supply voltage Vcc generated by the regulator 82, and the drain of which is connected to the node PX via a diode D5. The cathode of the diode D5 is connected to the node PX to prevent reverse current flow from the node PX side to the regulator 82.

[0146] Then, before supplying power to a load such as the power supply control unit 74, the power management MCU 80 turns on the application switch SWc to determine whether the third switch SWA2 or the fourth switch SWB2 has failed.

[0147] In other words, when the application switch SWc is turned on, if the third switch SWA2 or the fourth switch SWB2 does not fail, the power supply voltage Vcc is not applied to the first discharge path LA1 or the second discharge path LB1. Therefore, the voltage value detected by the voltage detection unit 86 or 88 is zero. However, if the third switch SWA2 or the fourth switch SWB2 fails due to a short circuit, the voltage value detected by the voltage detection unit 86 or 88 is not zero, but a voltage value equivalent to Vcc.

[0148] For this reason, the power supply management MCU 80 turns on the application switch SWc as described above, acquires the voltage value detected by the voltage detection unit 86 or 88, and if the voltage value is not zero, determines that the third switch SWA2 or the fourth switch SWB2 has failed. If the power supply management MCU 80 determines that the third switch SWA2 or the fourth switch SWB2 has failed, it does not supply power to loads such as the power supply control unit 74, and uses the interface device 20 to notify the user of the failure.

[0149] <Discharge battery switching control> Next, a description will be given of a discharging battery switching control process executed in the power management MCU 80 when switching the power supply source to the loads such as the power control unit 74 from the first battery pack 30A to the second battery pack 30B.

[0150] The discharge battery switching control is realized by the CPU in the power supply management MCU 80 executing a program stored in advance in a ROM or the like. When the discharging battery switching control process shown in FIG. 4 is started, the power supply source is the first battery pack 30A, and therefore the first discharging path LA1 is selected as the power supply path.

[0151] Therefore, when the discharging battery switching control process is started, the first switch SWA1 and the third switch SWA2 on the first discharging path LA1 are in the ON state, and the second switch SWB1 and the fourth switch SWB2 on the second discharging path LB1 are in the OFF state.

[0152] Furthermore, when the discharging battery switching control process is started, the third switch SWA2 or the fourth switch SWA4 has not been determined to be faulty, so the detection switches SWa, SWb and the application switch SWc are also in the off state.

[0153] In this state, when the discharge battery switching control process for switching the power supply source from the first battery pack 30A to the second battery pack 30B is started, first, in S110, a fault diagnosis process for the third switch SWA2 is performed as shown in Fig. 3. This fault diagnosis process is performed according to the procedure shown in Fig. 5.

[0154] That is, in the fault diagnosis process, the detection switch SWa is switched on in S210, and then the third switch SWA2 is switched off in S220. As a result, the voltage across the body diode D3 in the third switch SWA2 is applied between the two input terminals of the voltage detection unit 90.

[0155] In this state, power is supplied from the first battery pack 30A to a load such as the power supply control unit 74 via the first discharge path LA1, and therefore, if the third switch SWA2 is in the off state, a load current flows through the body diode D3. Therefore, a predetermined forward voltage is generated across the body diode D3. However, if the semiconductor switch Q3 constituting the third switch SWA2 has a short-circuit fault, no load current flows through the body diode D3, and the voltage across the body diode D3 is zero or a voltage significantly lower than the forward voltage.

[0156] Therefore, in the failure diagnosis process, at subsequent S230, it is determined based on the voltage value detected by the voltage detection unit 90 whether or not the voltage detection unit 90 has detected the forward voltage of the body diode D3.

[0157] If it is determined in S230 that a forward voltage has been detected, it is determined in S240 that the third switch SWA2 is normal, and the process proceeds to S260. If it is determined in S230 that a forward voltage has not been detected, it is determined in S250 that the third switch SWA2 has failed, and the process proceeds to S260.

[0158] In S260, the detection switch SWa is returned to the OFF state, and in the following S270, the third switch SWA2 is returned to the ON state. As a result, these switches SWa and SWA2 return to their initial states at the start of the discharging battery switching control process. Then, the fault diagnosis process is terminated.

[0159] Returning to FIG. 4, when the fault diagnosis process in S110 is completed, the process proceeds to S120, where it is determined whether or not the third switch SWA2 is normal based on the diagnosis result of the fault diagnosis process. If it is determined in S120 that the third switch SWA2 is normal, the process proceeds to S130, where the discharging battery switching process is executed, and the discharging battery switching control process ends.

[0160] If it is determined in S120 that the third switch SWA2 is not normal, that is, that it has failed, the process proceeds to S140, where abnormality processing is executed, and the discharging battery switching control processing ends.

[0161] In the abnormal state processing of S140, since the third switch SWA2 has a short-circuit fault and the first discharge path LA1 cannot be cut off, a motor stop command is output to the centralized control MCU 70 and an error is displayed on the display unit 20C.

[0162] When the centralized control MCU 70 receives a motor stop command from the power supply control MCU 80, it instructs the motor control circuits 62, 64, and 66 to stop driving the corresponding motors 32, 34, and 36.

[0163] Next, the discharging battery switching process in S130 is executed according to the procedure shown in Fig. 6. That is, in the discharging battery switching process, in S310, the third switch SWA2 is switched from the on state to the off state, and then in S320, the second switch SWB1 is switched from the off state to the on state.

[0164] In the next step S330, the first switch SWA1 is switched from the on state to the off state, and in the next step S340, the fourth switch SWB2 is switched from the off state to the on state, thereby completing the discharging battery switching process.

[0165] In this way, in the discharging battery switching process, as shown in FIG. 7, the first to fourth switches SWA1, SWB1, SWA2, and SWB2 are inverted from the initial state in the order SWA2, SWB1, SWA1, and SWB2.

[0166] Therefore, when the discharging battery switching process is executed, first, the third switch SWA2 is turned off at time t1, and the body diode D3 prevents a reverse current flow in the first discharging path LA1.

[0167] Next, at time t2, the second switch SWB1 is turned on, and both the first discharge path LA1 and the second discharge path LB1 are conductive. At this time, the output voltage of the second battery pack 30B is higher than that of the first battery pack 30A before the path switching. However, because the third switch SWA2 is off, no current flows from the second battery pack 30B to the first battery pack 30A.

[0168] Next, at time t3, the first switch SWA1 is turned off, the first discharge path LA1 is interrupted, and the power supply path to the load is switched from the first discharge path LA1 to the second discharge path LB1.

[0169] Finally, at time t4, the fourth switch SWB2 is turned on, and therefore the load current does not flow through the body diode D4 of the fourth switch SWB2 in the second discharge path LB1. Therefore, power can be supplied with low loss to the load, such as the power supply control unit 74, from the second battery pack 30B via the second discharge path LB1.

[0170] <Effect 2> As described above, according to this embodiment, when the power supply path to a load such as the power supply control unit 74 is switched from the first discharge path LA1 to the second discharge path LB1, it is possible to prevent a momentary interruption in the supplied power.

[0171] Furthermore, the body diode D3 of the third switch SWA2 can prevent current from flowing from the second battery pack 30B, which is the power supply source after the path switching, to the first battery pack 30A, which is the power supply source before the path switching.

[0172] Furthermore, before switching the power supply path, a failure determination is made for the third switch SWA2, and if the third switch SWA2 is found to be faulty, the driving of the motors 32, 34, 36 is stopped and a notification to that effect is given via the display unit 20C.

[0173] Therefore, when the third switch SWA2 is faulty, the first discharge path LA1 cannot be interrupted, and it is possible to prevent an overcurrent from flowing through the first discharge path LA1 or a reverse current from flowing through the first discharge path LA1, thereby improving the safety of the control device 50.

[0174] Although the embodiments for carrying out the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be carried out in various modified forms. [Variation 1] For example, in the above embodiment, the third rectifier element formed of the body diode D3 is described as being provided in series on the first discharge path LA1 between the first switch SWA1 and the connection point PX. However, the third rectifier element may be provided on the first discharge path LA1 between the first battery pack 30A and the first switch SWA1 and configured to block current from flowing from the connection point PX to the first battery pack 30A.

[0175] Furthermore, when the third rectifier element is provided on the first discharge path LA1 between the first battery pack 30A and the first switch SWA1 in this manner, a third switch such as a semiconductor switch Q3 may be connected in parallel to the third rectifier element so that both ends of the third rectifier element can be made conductive / cut off.

[0176] Similarly, a fourth rectifier element formed of a body diode D4 may be provided on the second discharge path LB1 between the second battery pack 30B and the second switch SWB1 and configured to block current from flowing from the connection point PX to the second battery pack 30B. In this case, a third switch such as a semiconductor switch Q4 may be connected in parallel to the fourth rectifier element so that both ends of the fourth rectifier element can be made conductive / cut off.

[0177] [Variation 2] In the above embodiment, the procedure for switching the power supply path to the load from the first discharge path LA1 to the second discharge path LB1 has been described using the flowcharts of FIGS. 4 to 6 and the time chart of FIG.

[0178] However, even when the power supply path to the load is switched from the second discharge path LB1 to the first discharge path LA1, the same effect as above can be obtained by carrying out the same procedure as above. In this case, however, the switches to be turned on are reversed when the power supply path is changed to the first discharge path LA1 and when the power supply path is changed to the second discharge path LB1. Therefore, the order of the switches that change the on / off state during switching can be reversed from that described above.

[0179] Furthermore, when the power supply path to the load is switched from the second discharge path LB1 to the first discharge path LA1, the detection switch SWb is turned on and the voltage across the fourth switch SWB2 is detected via the voltage detection unit 90. In this way, a fault diagnosis of the fourth switch SWB2 can be performed using the same procedure as in the above embodiment.

[0180] [Variation 3] In addition, in the above embodiment, when the stop condition for stopping the power supply from the first battery pack is met, the on / off states of the third switch SWA2, the second switch SWB1, the first switch SWA1, and the fourth switch SWB2 are reversed in this order.

[0181] However, when a stop condition for stopping the power supply from the first battery pack is met, the on / off states of the third switch SWA2 and the second switch SWB1 may be reversed in that order, and the order in which the other switches are reversed may be set arbitrarily. That is, the first switch SWA1 and the fourth switch SWB2 may be reversed in the order of the fourth switch SWB2 and the first switch SWA1, or may be reversed simultaneously.

[0182] [Variation 4] In the above embodiment, when the power supply path to the load is switched from the first discharge path LA1 to the second discharge path LB1, a fault diagnosis of the third switch SWA2 is performed before the path switching. However, in the discharge battery switching process of S130, a fault diagnosis process of the fourth switch SWB2 may be performed as shown in FIG.

[0183] If a fault diagnosis of the fourth switch SWB2 is performed in S130, it is determined in S150 whether the fourth switch SWB2 is normal. If it is determined in S150 that the fourth switch SWB2 is not normal, the same abnormal state processing as in S140 is executed in S160.

[0184] By executing the discharging battery switching control process in this manner, it becomes possible to perform a failure determination not only for the third switch SWA2 but also for the fourth switch SWB2 in the discharging battery switching control process.

[0185] In addition, when determining whether the fourth switch SWB2 has a fault in the discharging battery switching process of S130, as shown in Figure 9, after executing the process of S320, a fault diagnosis process for the fourth switch SWB2 is executed in S322.

[0186] That is, after the process of S320 is executed, the first switch SWA1 and the third switch SWA2 are in the ON state, and the second switch SWB1 and the fourth switch SWB2 are in the OFF state. Therefore, in the fault diagnosis process of S322, as shown in FIG. 10, the detection switch SWb is turned on in S410, so that the voltage across the fourth switch SWB2 is applied between the two input terminals of the voltage detection unit 90.

[0187] In this case, if the fourth switch SWB2 is in the off state, a load current flows through the body diode D4 of the fourth switch SWB2, and the voltage detection unit 90 detects a predetermined forward voltage. However, if the fourth switch SWB2 has a short-circuit fault, no load current flows through the body diode D4, and the voltage across the body diode D4 becomes zero or a voltage significantly lower than the forward voltage.

[0188] Therefore, in the failure diagnosis process of S322, in the following S420, it is determined based on the voltage value detected by the voltage detection unit 90 whether or not the forward voltage of the body diode D4 is detected by the voltage detection unit 90.

[0189] If it is determined in S420 that a forward voltage has been detected, the fourth switch SWB2 is determined to be normal in S430, and the process proceeds to S450. If it is determined in S420 that a forward voltage has not been detected, the fourth switch SWB2 is determined to be faulty in S440, and the process proceeds to S450. In S450, the detection switch SWb is returned to the OFF state, and the fault diagnosis process of S322 is terminated.

[0190] In this way, by executing the failure diagnosis process of S322, it is possible to perform a failure diagnosis of the fourth switch SWB2 during the execution of the discharging battery switching process. Furthermore, if this failure diagnosis process determines that the fourth switch SWB2 has failed, the drive of each of the motors 32, 34, 36 can be stopped and a warning can be given to the user, thereby improving the safety of the control device 50.

[0191] [Variation 5] In the above embodiment, characteristic configurations related to the technology of the present disclosure include "Configuration 1 of the control device" that achieves the above-mentioned "Effect 1" and "Configuration 2 of the control device" that achieves the above-mentioned "Effect 2."

[0192] Furthermore, "Configuration 2 of the control device" does not necessarily have to be combined with "Configuration 1 of the control device," and effective effects can be obtained by "Configuration 2 of the control device" alone. In this case, the configuration of the electrical equipment that can obtain the desired effects in "Configuration 2 of the control device" can be described as follows:

[0193] That is, the electrical device of the third modification is as follows: a drive circuit configured to drive a controlled object; a battery mounting section configured to be able to mount a battery pack; a discharge path configured to supply DC power from the battery pack attached to the battery attachment portion to the drive circuit; a main switch provided in the discharge path and configured to turn on / off the discharge path; a rectifying element provided on the first discharge path in series with the main switch and configured to block current from flowing from the drive circuit side to the battery pack; a secondary switch connected in parallel to the rectifying element and configured to turn on / off both ends of the rectifying element; a power supply control circuit configured to control the on / off states of the main switch and the sub switch; a voltage detection circuit configured to detect a voltage across the rectifying element; Equipped with The power supply control circuit may be configured to turn on the main switch and the secondary switch when supplying DC power from the battery pack to the drive circuit, and to turn on the main switch and turn off the secondary switch under predetermined conditions, detect the voltage across the rectifier element via the voltage detection circuit, and determine whether or not the secondary switch has failed from the detected voltage across the rectifier element.

[0194] According to the electrical device of this variant example 3, the rectifier element prevents backflow from the controlled object or other battery packs, and the secondary switch, when turned on, suppresses the current flowing through the rectifier element, thereby preventing deterioration or failure of the rectifier element.

[0195] In this case, the main switch corresponds to the first switch SWA1 in the above embodiment, and the secondary switch corresponds to the third switch SWA2 in the above embodiment. Furthermore, the electric device of Modification 3 may include a first discharge path LA1 and a second discharge path LB1 as discharge paths, and each of the discharge paths LA1 and LB1 may be provided with a main switch and a sub switch, as in the above embodiment. In this way, the sub switches can suppress current flow between the battery packs connected to each of the discharge paths LA1 and LB1.

[0196] Furthermore, by further combining the components described in "Configuration 2 of the control device," the electrical device of Variation 3 can achieve unique effects, such as the ability to diagnose failures in the secondary switch.

[0197] [Other embodiments] In the above embodiment, the first switch SWA1, the second switch SWB1, the third switch SWA2, and the fourth switch SWB2 have been described as having n-channel MOSFETs as the semiconductor switches Q1 to Q4. However, each of these semiconductor switches Q1 to Q4 may be in the form of a p-channel MOSFET. Furthermore, the semiconductor switches Q1 to Q4 may be any type that can conduct / cut off the discharge path, and may be, for example, a bipolar transistor.

[0198] Next, in the above embodiment, the robot dust collector 1 has been used as an example to describe the electrical device of the present disclosure, but the technology of the present disclosure can be applied to any electrical device that operates by receiving power from a battery pack attached to a battery attachment section. For example, the technology of the present disclosure can be applied to various electrical devices such as rebar tying machines, lawn mowers, transport vehicles, refrigerator / warmers, and lighting devices.

[0199] In the above embodiments, multiple functions of one component may be realized by multiple components, or one function of one component may be realized by multiple components. Furthermore, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. All aspects included in the technical idea identified only by the wording of the claims are embodiments of the present disclosure.

[0200] The technology disclosed herein can be configured as an electrical device, and can also be realized in various forms, such as a control system for various electrical devices, a program for realizing the various controls described above on a computer, a non-transient physical recording medium such as a semiconductor memory on which this program is recorded, and a control method for electrical devices. [Explanation of symbols]

[0201] 4A...first battery mounting section, 4B...second battery mounting section, 30A...first battery pack, 30B...second battery pack, 62...suction motor control circuit, 64...wheel motor control circuit, 66...brush motor control circuit, 70...centralized control MCU, 72, 82...regulators, 74, 84...power supply control section, 80...power supply management MCU, 90...voltage detection section, D1, D2, D3, D4...body diodes, DA1, DA2, DB1, DB1...diodes, LA1...first discharge path, LB1...second discharge path, PX...connection point, LA2...first power supply path, LB2...second power supply path, SWA1...first switch, SWB1...second switch, SWA2...third switch, SWB2...fourth switch.

Claims

1. a drive circuit configured to drive a controlled object; a first battery mounting portion configured to be able to mount a first battery pack; a first discharge path configured to supply DC power from the first battery pack attached to the first battery attachment portion to the drive circuit; a second battery mounting portion configured to be able to mount a second battery pack; a second discharge path configured to supply DC power from the second battery pack attached to the second battery attachment portion to the drive circuit; a connection point common to the first and second discharge paths, the connection point being on an opposite side of the first and second battery packs, and supplying the DC power from the first and second discharge paths to the drive circuit; a first switch provided on the first discharge path between the first battery pack and the connection point and configured to make / break the first discharge path; a second switch provided on the second discharge path between the second battery pack and the connection point and configured to conduct / cut off the second discharge path; a drive control circuit configured to control driving of the controlled object by the drive circuit; a first power supply circuit configured to generate a power supply voltage for the drive control circuit using the DC power supplied from the first battery pack or the second battery pack via the first discharge path or the second discharge path when the first switch or the second switch is in an on state, and supply the power supply voltage to the drive control circuit; a power supply control circuit configured to control the on / off states of the first switch and the second switch; a second power supply circuit configured to generate a power supply voltage for the power supply control circuit and supply the power supply voltage to the power supply control circuit; a first power supply path configured to supply the DC power from the first battery pack attached to the first battery attachment portion to the second power supply circuit; a first rectifying element provided on the first power supply path and configured to allow current to flow from the first battery pack to the second power supply circuit side and to block current from flowing from the second power supply circuit side to the first battery pack; a second power supply path configured to supply the DC power from the second battery pack attached to the second battery attachment portion to the second power supply circuit; a second rectifier element provided on the second power supply path and configured to allow current to flow from the second battery pack to the second power supply circuit side and to block current from flowing from the second power supply circuit side to the second battery pack; Electrical equipment with.

2. 2. The electrical device according to claim 1, a third rectifying element provided in series on the first discharge path between the first battery pack and the connection point, the third rectifying element configured to block current from flowing from the connection point to the first battery pack; a third switch connected in parallel to the third rectifying element and configured to connect / disconnect both ends of the third rectifying element; a fourth rectifying element provided in series on the second discharge path between the second battery pack and the connection point, the fourth rectifying element being configured to block current from flowing from the connection point to the second battery pack; a fourth switch connected in parallel to the fourth rectifying element and configured to connect / disconnect both ends of the fourth rectifying element; Electrical equipment with.

3. 3. The electrical device according to claim 2, The power supply control circuit the electrical device is configured to switch the power supply to the drive circuit and the first power supply circuit from the first battery pack to the second battery pack by inverting the on / off states of the third switch and the second switch in that order, and then inverting the on / off states of the first switch and the fourth switch, when a stop condition for stopping the power supply from the first battery pack is met while the first switch and the third switch are in an on state and the second switch and the fourth switch are in an off state.

4. The electrical device according to claim 2 or 3, A voltage detection circuit is provided. The power supply control circuit an electrical device configured to detect a voltage across the third switch via the voltage detection circuit when the first switch is in an on state and the third switch is in an off state, determine whether or not the third switch has failed, and, if it is determined that the third switch has failed, limit control of the controlled object by the drive circuit.

5. An electrical device according to claim 4 which relies on claim 3, The power supply control circuit and determining whether the third switch has failed before switching the power supply to the drive circuit and the first power supply circuit from the first battery pack to the second battery pack.

6. 6. The electrical device according to claim 5, The power supply control circuit the control circuit for the controlled object by the drive circuit is restricted when the second switch is turned on and the fourth switch is turned off, and when the power supply to the drive circuit and the first power supply circuit is switched from the first battery pack to the second battery pack, the control circuit detects a voltage across the fourth switch via the voltage detection circuit to determine whether the fourth switch has failed, and when it is determined that the fourth switch has failed, the control circuit restricts the control of the controlled object by the drive circuit.

7. The electrical device according to any one of claims 2 to 6, the third rectifier element and the third switch, and the fourth rectifier element and the fourth switch, are each configured by an FET having a body diode.

8. The electrical device according to any one of claims 1 to 7, the first switch and the second switch are each configured as an FET having a body diode, the body diodes of the FETs constituting the first switch and the second switch are configured to block current from flowing from the first battery pack and the second battery pack to the connection point, respectively.

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