Automated guided vehicle with wake-up circuit

Abstract

The invention provides an automatic guided vehicle (AGV) fleet system. The AGV fleet system is provided with a facility supervision system and a plurality of AGVs. Each AGV has a power control module including a wake-up circuit having at least one command input and at least one control output and operable by power received from a power source. The wake-up circuit includes a timer circuit coupled to the control output to change an output state of the control output according to the parameter (s) and one or more parameters configurable via the command input.

Description

Technical Field

[0001] The present invention relates to an automated guided vehicle (AGV) having wireless communication capabilities.

[0002] background

[0003] AGVs are used in commercial and industrial facilities to move parts and inventory between physical locations within the facility. They typically include an onboard (battery) power source and steering system to enable autonomous navigation using any of a variety of known technologies. Some AGVs include a wireless communication device (WCD) through which a computer-based supervisory system, typically located within the same facility, can issue commands and / or poll the AGV. Most AGVs in use today do not operate 24 hours a day, but rather according to work shifts, which may be dictated by other aspects of the manufacturing or inventory control process (particularly those involving workers). Therefore, in these cases, the AGV is manually powered on at the beginning of each shift or daily cycle and then manually powered off at the end of that shift or cycle. This is accomplished using a power switch. Once pressed, the AGV's main battery provides operating power to its circuitry, and a relay or other device locks out this operating power until the power switch or another button is activated, which shuts down the AGV. The AGV's circuitry, powered by the main battery, includes its steering and motor drives, as well as its WCD for wireless communication within the facility. Summary of the Invention

[0004] According to one aspect of the present invention, an automated guided vehicle (AGV) power control module is provided, which AGV power control module includes: a wake-up circuit having at least one command input and at least one control output and can be operated by power received from a power supply, wherein the wake-up circuit includes a timer circuit and at least one parameter that can be configured via the command input, and the timer circuit is coupled to the control output to change the output state of the control output according to the parameter.

[0005] In various embodiments, the AGV power control module may include one or more of the following features, alone or in any technically feasible combination:

[0006] - the timer circuit performs a sleep / wake cycle for which the control output is set to a first state during a sleep portion of the cycle and to a different second state during a wake portion of the cycle, and wherein the parameter is a sleep time parameter indicative of a duration of the sleep portion of the cycle.

[0007] - The timer circuit comprises a wake-up time parameter indicating the duration of the wake-up portion of the cycle.

[0008] - The second state of the control output comprises power sufficient to operate a wireless communication device (WCD).

[0009] -The control output includes a WCD power output, and wherein the wake-up circuit further includes a second control output, the second control output including an AGV power output capable of switching between a first state and a second state, the second state providing power sufficient to operate the AGV startup circuit, and wherein the wake-up circuit operates during the sleep portion of the cycle to maintain the WCD power output and the AGV power output in their first state, during which the power provided by the WCD power output and the AGV power output is insufficient to activate the WCD or the AGV startup circuit, respectively.

[0010] The wake-up circuit operates during a wake-up portion of the cycle to set the WCD power output to its second state, monitor the command input for an AGV start command, and set the AGV power output to its second state upon receipt of the AGV start command.

[0011] The wake-up circuit further comprises a relay that switches an output state of the control output between a first state and a second state based on one or more commands received via the command input.

[0012] -The AGV power control module further includes an AGV start circuit input and an AGV start circuit output, wherein the control output of the wake-up circuit and the AGV start circuit output are connected together to the AGV start circuit input in a logical OR manner, so that the power signal on either or both of the control output and the AGV start circuit output causes the power control module to output a power signal on the AGV start circuit input.

[0013] - The wake-up circuit control output and the AGV start circuit output are connected together in a logical OR manner using a diode.

[0014] The at least one command input comprises a multi-wire bus interface, and the at least one parameter comprises a plurality of time / date parameters stored in the wake-up circuit and configurable via the bus interface.

[0015] the timer circuit comprises a software-controlled electronic processor and a real-time clock which can be set by the electronic processor using the time / date parameters, and wherein the wake-up circuit comprises a plurality of registers, each register being accessible by the electronic processor and each register storing one of the time / date parameters.

[0016] - the wake-up circuit operates in any of a plurality of operating modes including a sleep / wake-up mode and a shift schedule mode, wherein the wake-up circuit can switch between the operating modes according to a mode command received via the command input, and wherein the wake-up circuit is configured to receive an output control command via the command input and to change the output state of the control output based on the output control command independent of the operating mode.

[0017] According to another aspect of the present invention, an AGV is provided, which includes the power control module.

[0018] In another aspect of the present invention, an AGV fleet system is provided, which includes: multiple AGVs and a non-transitory computer-readable medium, on which an AGV supervision control program is stored. The AGV supervision control program can be executed by one or more electronic processors of a facility supervision system (FSS) to perform an AGV supervision process, which is used to communicate with and control the AGV via wireless communication from the FSS, wherein the AGV supervision program enables the FSS to communicate with the wake-up circuit of each AGV via the AGV wireless communication device, thereby starting the AGV from a power-off state.

[0019] Another aspect of the present invention provides an automated guided vehicle (AGV) fleet system, which includes: a plurality of AGVs, each AGV having one or more power supplies, a plurality of motors for driving and steering the AGV, a wireless communication device, a wake-up circuit, and an AGV controller, which AGV controller can be operated by power from the (multiple) power supplies and is coupled to: (i) the motor to control the movement and steering of the AGV, (ii) the wireless communication device for communicating with the AGV, and (iii) the wake-up circuit for wirelessly starting the AGV; and a non-transitory computer-readable medium, which has an AGV supervision control program stored thereon, which can be executed by one or more electronic processors of a facility supervision system (FSS) to perform an AGV supervision process, which is used to communicate with and control the AGV via wireless communication from the FSS, wherein the AGV supervision program enables the FSS to communicate with the wake-up circuit of each AGV via the AGV wireless communication device, thereby starting the AGV from a power-off state.

[0020] In another aspect of the present invention, an automated guided vehicle (AGV) fleet system is provided, the AGV fleet system comprising: a plurality of AGVs located within a facility, each AGV having one or more power supplies, a plurality of motors for driving and steering the AGV, a wireless communication device, a wake-up circuit, and an AGV controller, the AGV controller being operable by power from the (multiple) power supplies and coupled to: (i) the motors to control the movement and steering of the AGV, (ii) the wireless communication device for communicating with the AGV, and (iii) the wake-up circuit for wirelessly starting the AGV; and a facility supervision system (FSS), the FSS comprising one or more FSS controllers, the one or more FSS controllers comprising an electronic processor and a memory accessible by the processor, the memory storing software comprising instructions executable by the electronic processor to perform an AGV supervision control process for communicating and controlling the AGV, the FSS further comprising a plurality of wireless access points distributed around the facility and connected to the (multiple) FSS controllers, wherein the FSS controller operates under the control of the software to communicate with the wake-up circuit of each AGV via the AGV wireless communication device and one or more of the wireless access points.

[0021] Another aspect of the present invention relates to a method for operating an automated guided vehicle (AGV), the method comprising: operating a power control module of the AGV in a sleep mode; switching from the sleep mode to the wake-up mode by generating a wake-up signal; automatically powering on a wireless communication device on the AGV in response to the wake-up signal while maintaining the AGV in a shut-down state; monitoring a start command wirelessly received by the wireless communication device; and automatically powering on the AGV when a start command is received during monitoring.

[0022] In various embodiments, the method may include one or more of the following features, alone or in any technically feasible combination:

[0023] The operating step further comprises operating the power control module in the sleep mode for a first time period, and wherein the monitoring step further comprises monitoring for a start command during a second time period following the wake-up signal.

[0024] - The method further comprises automatically powering off the wireless communication device and returning to the sleep mode when no activation command is received during the second time period.

[0025] - The method further comprises performing a repeating cycle of alternatingly operating in the sleep mode for a first period of time and operating in the wake mode for a second period of time until a start command is received and the AGV is powered on.

[0026] -The operating steps further include: operating the processor of the power control module in a low-power sleep mode; operating the timer circuit for a first time period; and upon expiration of the first time period, switching the processor out of the low-power sleep mode by sending an interrupt from the timer circuit to the processor.

[0027] - The switching step includes switching to wake-up mode based on the shift schedule start time and the current time provided by the real-time clock on the AGV.

[0028] In still another aspect of the present invention, a method of operating an automated guided vehicle (AGV) is provided, the method comprising: operating a power control module of the AGV in a sleep mode when the AGV is in an off state; comparing a current time with a scheduled start time using a real-time clock in the power control module; and switching the power control module from the sleep mode to the wake mode and automatically powering on the AGV from the off state when the current time has a predetermined necessary relationship with the scheduled start time. In at least some embodiments, the predetermined necessary relationship is that the current time is equal to the scheduled start time. The switching step may further comprise automatically powering on a wireless communication device on the AGV and establishing a wireless communication connection between the AGV and a facility supervision system at the facility where the AGV is located. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Preferred exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like names represent like elements, and in which:

[0030] Figure 1 Diagrammatically depicting a facility with a facility supervision system (FSS) and a fleet of automated guided vehicles (AGVs), all of which are constructed in accordance with an embodiment of the present invention;

[0031] Figure 2 yes Figure 1 an electronic circuit diagram of one of the respective AGVs including a wake-up circuit forming part of a power control module of the AGV;

[0032] Figure 3 yes Figure 2 a list of addressable registers for storing commands, parameters, and status information of the wake-up circuit; and

[0033] Figure 4 yes Figure 1 A simplified diagram of the facility supervision system. DETAILED DESCRIPTION

[0034] refer to Figure 1, a facility 10 is diagrammatically shown having a facility supervision system (FSS) 12 and a fleet 14 of various automated guided vehicles (AGVs) 16. As a general rule, the fleet 14 of AGVs 16 operates during any particular work shift under the coordination of the FSS 12 to move materials, inventory, and / or production workpieces between locations in the facility. As is known to those skilled in the art, one common such application is the movement of parts being manufactured between various workstations, for which purpose the AGVs may include tools and / or movable platforms operated by scissor lifts, rigid chains, hydraulics, or the like.

[0035] Each AGV 16 includes the basic components of a typical AGV, such as a body 18 covering a chassis that supports a plurality of wheels 20 (including one or more steerable wheels 22), and one or more servo motors 24 ( 22 ) for steering and driving the wheels 20 of the AGV. Figure 2 Various methods for guiding the path of the AGV 16 are known to those skilled in the art, including in-floor wire tracking and magnetic strip tracking, as taught in U.S. Patent No. 8,751,142 B2. Each AGV 16 also includes at least one control panel 26 including a human machine interface (HMI) 28 ( Figure 2 To this end, the FSS 12 has at least one (but typically a plurality) of wireless access points 32 spaced around the facility 10 near the fleet 14 .

[0036] If combined Figure 2 As described in more detail, each of the AGVs 16 further includes AGV electronics that enable the AGV to achieve its desired functionality and operability. Figure 1 The construction and integration of the basic AGV components are known to those skilled in the art.

[0037] Figure 2 The AGV 16 is diagrammatically depicted including AGV electronics 40 and a power control module (PCM) 60 that provides the AGV 16 with enhanced functionality relative to typical AGVs currently used in manufacturing and inventory processing. Figure 2 The components and circuitry comprising the AGV electronics 40 are shown to the right of the dashed line in FIG, and the components and circuitry comprising the power control module 60 are shown to the left of the dashed line.

[0038] The AGV electronics 40 includes, as its primary electrical components, an AGV programmable logic controller (PLC) 42 that provides overall control and operation of the AGV, and a wireless communication device (WCD) 44 having an antenna 30 for communication between the PLC 42 and the FSS 12. Onboard power is supplied by a 24V dc-dc converter 46, which derives its input power from a 48V dc battery power source 48. The dc-dc converter 46 provides operating power to the PLC 42 and the WCD 44. The 48V battery power is supplied directly to operate the higher voltage AGV motors 24. Additional supply voltages can be generated from the 24V power from the dc-dc converter 46 as needed or desired for other parts of the AGV electronics 40.

[0039] AGV PLC 42 may be any suitable programmable logic controller, such as those known for use in AGVs. Similarly, WCD 44 may be a network-enabled Wi-Fi client module using the 802.11 protocol for communication with access point 32 of FSS 12 and a wired Ethernet connection. For example, WCD 44 may use a Siemens TM The WCD 44 is connected to the PLC 42 using a wired bus and a bus protocol such as PROFINET.

[0040] In addition to the PLC 42, each of the other major components of the AGV electronics 40 can be addressed from the FSS 12 via the WCD 44; for example, using a different static IP address for each component. This can include the HMI 28, the WCD 44 itself, and Figure 2 Other circuits not explicitly shown in the drawings, such as each of a plurality of magnetic sensor boards that may be included when using the guidance system of the aforementioned US Patent No. 8,751,142 B2.

[0041] The startup and shutdown of the AGV is accomplished using an AGV operating power control circuit that utilizes relay logic, which is illustrated using schematic symbols distributed among the AGV electronics 40. The AGV operating power control circuit includes an AGV startup circuit 50 and an AGV shutdown circuit 52. The startup circuit 50 includes a normally open (NO) momentary power switch AGV-ON and a first control relay having an energizable coil CR1 that controls three separate NO contact pairs CR1-1, CR1-2, and CR1-3. The shutdown circuit 52 includes a normally closed (NC) power interrupt switch AGV-OFF ​​and a second control relay having an energizable coil CR2 that is operated by the PLC 42 to control a single NC contact pair CR2-1.

[0042] The basic operation of the startup circuit 50 is as follows. At the start of a work shift, the operator activates the momentary switch AGV-ON, connecting the 48V battery power to the DC-DC converter 46, which then generates a 24V DC output that it supplies to the PLC 42 and WCD 44. For AGVs that do not include a power control module (PCM) 60, the left side of the switch AGV-OFF ​​of the shutdown circuit 52 can be connected to the input of the relay coil CR1 as shown by the dotted line. Since both the shutdown component CR2-1 and AGV-OFF ​​use normally closed contacts, the 24V power is connected to the relay coil CR1 through both, energizing it and closing three separate contact pole groups CR1-1, CR1-2, and CR1-3. Since the (now closed) contact CR1-1 shunts power across the momentary switch AGV-ON, this has the effect of locking the power on. This also provides operating power to the motor 24 via CR1-2. The time required for the dc-dc converter 46 to power up, supply its 24V output power, and activate coil CR1 is on the order of milliseconds, typically well below 1 second, allowing the AGV-ON switch to simulate the response of a locking switch while also allowing electronic shutdown of the AGV. This basic operation of the start circuit 50 (with power routed to CR1 via the dotted connection) allows only manual activation of the start via the switch AGV-ON.

[0043] The AGV 16 can be shut down manually using the AGV-OFF ​​switch, or electronically via the PLC 42, which energizes relay coil CR2. Pressing the AGV-OFF ​​switch interrupts the 24V power supply energizing relay coil CR1, thereby opening contact CR1-1 and stopping the flow of power from battery 48 to DC-DC converter 46. Consequently, when the AGV-ON switch is released, coil CR1 no longer receives power. Contact CR1-2 also returns to its normally open position, cutting off power to motor 24. The AGV 16 is thus de-energized. A similar shutdown can also be achieved using the PLC 42. Activating relay coil CR2 via the PLC 42 opens contact CR2-1, which is connected in series with the AGV-OFF ​​switch, thereby having the same effect as de-energizing DC-DC converter 46. Consequently, when coil CR2 is deactivated, relay coil CR1 is no longer energized, and contact CR2-1 then returns to its normally closed state.

[0044] According to the illustrated embodiment of the present invention, the PCM 60 is connected to the AGV electronics 40 to allow the AGV 16 to be started in an electronically controlled manner; that is, without manually activating the switch AGV-ON. This is accomplished by eliminating the dotted connection between the switch AGV-OFF ​​of the closure circuit 52 and the relay coil CR1, and instead providing the start circuit 50 with an AGV start circuit input 54 and an AGV start circuit output 56, both of which the PCM 60 uses to allow both manual start via the switch AGV-ON and automatic start via the PCM 60. Via the AGV start circuit input 54, the PCM 60 can provide an activation or power signal to the AGV electronics 40 that turns on the AGV, similar to manually operating the AGV-ON switch. As discussed in detail below, the activation signal can be generated automatically by the PCM 60, such as at certain times of the day or after predetermined time intervals, or when directed by the FSS 12.

[0045] The PCM 60 includes a wake-up circuit 62 that operates from a 24v auxiliary battery 64. The wake-up circuit 62 includes a set of 24v relay switch control outputs, including an AGV power output 66 that generates an AGV_ON signal and is logically ORed together with the AGV start circuit output 56 such that a 24v power signal on either or both of the AGV power output 66 and the AGV start circuit output 56 causes the PCM 60 to output a power signal to the AGV start circuit input 54. As described above, this power signal then energizes relay coil CR1, thereby closing contacts CR1-1 and CR1-2, thereby providing operating power to the motor 24 and the rest of the AGV electronics via the dc-dc converter 46. Figure 2 As shown, such bonding of the 24v signal line 56 originating from the dc-dc converter 46 and the 24v signal line 66 from the wake-up circuit 62 can be accomplished using diodes 68 and 70 connected in series with the wake-up circuit control output and the AGV start circuit output, respectively, with their cathodes connected together at the input of the relay coil CR1.

[0046] It will be understood that the start circuit input 54 and output 56 can be implemented physically, as shown where the PCM 60 is physically separate from the AGV electronics 40, or can be implemented logically where the PCM 60 and AGV electronics 40 are physically integrated together; for example, by logically utilizing a dashed connection to relay coil CR1 as the start circuit output 56 and inserting a steering diode 70 in series with that connection.

[0047] Due to this or configuration of the control input to relay coil CR1, the wake-up circuit 62 can start the AGV 16 via one of its control outputs; specifically, via the AGV power output 66, which provides the signal AGV_ON. In the illustrated embodiment, this automatic AGV start-up is accomplished using a timer circuit 75 to implement a cyclic sleep / wake-up pattern or to execute the process based on a shift schedule. This approach is described further below. In another embodiment, the automatic start-up can be accomplished using a simpler timer circuit that operates based on a single configurable parameter, such as a specified time period for the wake-up circuit to operate in sleep mode. Upon expiration of this time period, the PCM 60 wakes up and changes the output state of at least one of the control outputs (e.g., to AGV_ON at output 66 or WCD_ON at output 84), thereby either directly initiating an AGV start-up or simply waking up the WCD 44, and allowing the FSS 12 to determine whether to start the AGV 16 or return to sleep mode. The sleep time parameter can be configured by the FSS 12 and transmitted to the wake-up circuit via the WCD 44.

[0048] To provide enhanced functionality, in addition to the aforementioned automatic start-up of the AGV 16, the wake-up circuit 62 includes additional components and circuitry. It utilizes a central processing unit (CPU) 72 and a real-time clock (RTC) 74 together to form a timer circuit 75. The wake-up circuit 62 further includes an I / O controller 76, an optical isolator 77, a relay 78, and registers 80, which form part of a Modbus TCP terminal server 82. This terminal server 82 uses a physical multi-wire bus interface, such as an RJ45 connector and CAT 6, or other suitable Ethernet cable, connected to both the wake-up circuit 62 and the Ethernet port on the WCD 44. The Modbus TCP terminal server 82 provides the wake-up circuit 62 with a command input through which it can receive commands, as well as parameters used by the wake-up circuit to perform its functions. It can also be used to provide status information to the wake-up circuit, or to return status information from the wake-up circuit to the FSS 12 or PLC 42. In other embodiments, the command input may be more or less complex. For example, in some embodiments, the command input may simply be one or more single-wire inputs through which the wake-up circuit receives command and / or parameter data. And as will be appreciated by those skilled in the art, these input commands and / or parameters may be processed and used to activate control outputs of the wake-up circuit using a processor such as the CPU 72 or using a gate array or simply using relay logic.

[0049] The functions of the wake-up circuit 62 may be implemented under the control of the CPU 72 using a program stored in the CPU's integrated flash memory. A suitable CPU may be the PIC32MX274F256BT-V / MM available from Microchip Technology Inc. The programming of the CPU 72 required to wake up the circuit 62 will become apparent to those skilled in the art based on the functional description of the operation of the circuit 62 below.

[0050] The wake-up circuit 62 operates when the AGV 16 is shut down (e.g., between work shifts). It operates to automatically start the AGV on command or according to a schedule. To do this, it runs in a low-power sleep mode on the auxiliary battery 64 while the AGV is shut down, and then wakes up periodically (using fixed or variable time intervals) to check for a start command from the FSS 12, or wakes up at a set time according to the scheduled start of the AGV. To this end, the wake-up circuit 62, and therefore the PCM 60 itself, can operate in either of two operating modes: a periodic (or cyclic) sleep / wake mode and a shift schedule mode. For the sleep / wake mode, the wake-up circuit 62 uses a timer circuit 75 including a CPU 72 and an RTC 74 to execute a periodic sleep / wake cycle that alternates between a sleep mode and a wake-up mode. These sleep and wake-up modes are represented by two different output states on the control output of the wake-up circuit 62 (e.g., output 66 or 84). The output state has a first state (e.g., 0 volts or high impedance) when in sleep mode and a different second state (e.g., a low impedance 24v power supply signal) when in wake-up mode. The wake-up circuit 62 continues to alternate between sleep mode and wake-up mode until a command to start the AGV 16 is received during wake-up mode. When the command is received, the circuit 62 responds by stopping the sleep / wake-up mode cycle and powering up the AGV 16. The mode uses at least two parameters, a sleep time parameter indicating the length of a first time period for operation in sleep mode, and a wake-up time parameter indicating the length of a second time period for operation in wake-up mode. These parameters can be specified and stored in the timer circuit 75 (e.g., in the CPU 72 or the RTC 74).

[0051] In the shift schedule mode, the timer circuit 75 uses the RTC 74 to switch from the sleep mode to the wake mode at a specific date and time stored in the RTC 74. A suitable real time clock is available from Ricoh TMand RV5C387A-E2-F available from other companies. The CPU 72 can also access the current time from the RTC 74 for various other purposes, such as determining the occurrence of the AGV's shutdown time according to a shift schedule. Resetting the clock 74 to the current date and time can also be done programmatically by the CPU 72; for example, periodically using time and date information from an online NIST or other time server.

[0052] Considering wakeup circuit 62 in more detail, data and command communications are accomplished via a Modbus TCP terminal server 82. Commands and parameters sent from WCD 44 to wakeup circuit 62 are stored in terminal server registers 80 according to the Modbus protocol. Similarly, status and other data can be loaded into these registers under the control of CPU 72 and reported to PLC 42 and / or FSS 12. Figure 3 4 and 5. Example addressable registers 80 are listed for commands and parameters, as well as for status information that can be returned from the wake-up circuit 62. Thus, for example, a sleep time parameter and a wake-up time parameter can be supplied from the FSS 12 to registers 40014 and 40015, respectively, for subsequent reading and use by the CPU 72. The CPU 72 can use the sleep time parameter to configure the RTC 74 so that when the PCM 60 is in sleep / wake mode, the RTC 74 will provide a periodic interrupt signal to the CPU 72 every xxx seconds, where xxx is the value of the sleep time parameter (and therefore the length of the first time period). The second time period (i.e., the wake-up time parameter) can also be used by the RTC 74 to indicate when the wake-up time expires, or can be used by the CPU 72 to determine when the wake-up time expires after switching out of sleep mode. In other embodiments, one or both of these parameters are hard-coded into the wake-up circuit and cannot be changed thereafter.

[0053] Similarly, for the shift schedule mode of operation, the date and time for the AGV 16 to start can be specified by the FSS 12 using some or all of registers 40008 to 40013, and the CPU 72 can configure the RTC 74 to generate an alarm (e.g., a CPU interrupt) when the specified date and time are reached. The advantage of using a real-time clock for the timer circuit is that it allows the AGV 16 to automatically schedule a wakeup when it is completely powered off and unable to communicate remotely.

[0054] In addition to providing parameter data, the PLC 42 and / or FSS 12 can also provide commands that directly control the operating mode of the wake-up circuit 62 and the control outputs 66, 84, and 86. This can be accomplished by allocating some of the available registers 80 as command registers for receiving mode commands and start commands. The operating mode can be set using register address 40017, and the two output states (0 or 24V) of the control outputs 66, 84, and 86 can be switched between using register address 40018 by identifying the desired associated relay 78 (relay A, B, or C, respectively) and the desired state (de-energized or energized). As will be appreciated, this forced control output state change can be performed independently of the operating mode (sleep / wake mode or shift schedule mode) and, therefore, allows remote activation of the AGV 16 regardless of the current state of the wake-up circuit 62.

[0055] Available registers 80 can also be assigned as status indicators. For example, register 40016 is used to return the AGV operating status (power off or on). This AGV status is obtained from the optoisolator 77, whose status is controlled by one of the three-pole contact sets CR1-3 of the main AGV power control relay CR1. Register addresses 40019 and 40020 can be used to read other digital input and output statuses and supply them back to the PLC 42 and / or FSS 12.

[0056] These data and commands to and from the wake-up circuit 62 via the Modbus TCP terminal server 82 are shifted into and out of registers 80 by the CPU 72. As will be appreciated by those skilled in the art, the CPU uses the I / O controller 76 to write to and read from the various input / output devices (i.e., the optoisolator 77 and the relay 78). The wake-up circuit 62 may also include a status LED 88 operated by the CPU 72 via the I / O controller 76 to indicate the operating status of the wake-up circuit 62 and any desired diagnostic information that may be obtained from the wake-up circuit.

[0057] Relays A and B of the wake-up circuit 62 control the states of the control outputs 84 and 66, respectively. Since these relays switch 24V power from the auxiliary battery 64, they provide enough power to operate the WCD 44 and the start-up circuit 50. Figure 2 As indicated, the WCD 44 may receive 24V operating power from the dc-dc converter 46 and the auxiliary battery 64 via relay A, respectively. TM For SCALANCE W700 series wireless communication devices, this can be accomplished by using their main and auxiliary power inputs. For other WCD 44 devices that do not have separate power inputs, two 24V power supplies can be tied together using a diode, as described above in conjunction with the startup circuit 50.

[0058] The use of these two individually controllable outputs 84 and 66 enables a step-by-step wakeup process, in which only a portion of the AGV electronics is initially powered up so that it can monitor and receive an AGV start command, and if such a start command is received, a full power-up of the AGV can be automatically performed. Thus, the wakeup circuit 62 operates during the sleep portion of the cycle (sleep mode) to maintain the WCD_ON power output 84 and the AGV_ON power output 66 in their first states (relays A and B open contacts), during which the power they provide is insufficient to activate the WCD or AGV start circuits, respectively. Furthermore, the wakeup circuit 62 operates during the wakeup portion of the cycle (wakeup mode) to: (i) set the WCD_ON power output 84 to its second state (relay A contacts closed), (ii) monitor for a command input for an AGV start command (e.g., using register 40018 to listen for DO_FORCE relay B energization), and (iii) set the AGV power outputs to their second state when an AGV start command is received.

[0059] This step-by-step startup of the AGV can be used in either the sleep / wake-up mode or the shift schedule operation mode. Using the AGV 16 and its PCM 60, this step-by-step wake-up mode can be implemented by methods including the following:

[0060] Power control module to operate the AGV in sleep mode;

[0061] switching from a sleep mode to a wake-up mode by generating a wake-up signal;

[0062] automatically powering on a wireless communication device on the AGV in response to a wake-up signal while maintaining the AGV in a powered-down state;

[0063] monitoring for an activation command wirelessly received by the wireless communication device; and

[0064] When a start command is received during the monitoring period, the AGV is automatically powered on.

[0065] The RTC 74 can be used to perform the switching step to generate a wake-up signal as an interrupt that is sent to the CPU 72 when the sleep mode period expires (e.g., after 300 seconds). During sleep mode, the CPU 72 can enter its own low-power sleep mode in which it stops most of its functions until an interrupt is received on its designated input pin. Thus, an interrupt from the RTC 74 to the CPU 72 can be an interrupt that switches it back from its low-power mode to full operation. This allows the AGV electronics 40 to be completely powered off, and the PCM 60 itself to be completely powered off, except for the RTC 74 and any power regulators that operate on the auxiliary battery 64 required to run the RTC.

[0066] As described above, automatically powering on the WCD 44 can be accomplished using relay A of the wake-up circuit under the control of the CPU 72, while keeping relay B deactivated so that the AGV remains in its off state. The wake-up circuit 62, now operating in wake-up mode, can then monitor register 80 for a start command received from the FSS 12 via the WCD 44. And, if / when received, the CPU 72 can activate relay B to start the AGV 16.

[0067] Additional aspects of this step-by-step method will be apparent based on the above description of the illustrated embodiments. For example, the method may include any of these additional features:

[0068] The operating step further includes operating the power control module in the sleep mode for a first time period, and wherein the monitoring step further includes monitoring for a start command during a second time period following the wake signal;

[0069] The method further includes automatically powering off the wireless communication device and returning it to the sleep mode when the activation command is not received during the second time period;

[0070] The method further includes performing a repeating cycle of alternating operating in the sleep mode for a first period of time and operating in the wake mode for a second period of time until a start command is received and the AGV is powered on;

[0071] The operation steps further include:

[0072] - an electronic processor to operate the power control module in a low-power sleep mode;

[0073] - operating the timer circuit for a first period of time; and

[0074] - upon expiration of the first time period, switching the electronic processor out of the low power sleep mode by sending an interrupt from the timer circuit to the electronic processor;

[0075] The switching step includes switching to a wake-up mode based on the shift schedule start time and the current time provided by a real-time clock on the AGV.

[0076] For the shift schedule operation mode, the AGV does not need to use a step-by-step startup process, but can use the following method to start:

[0077] When the AGV is in the off state, a power control module for operating the AGV in a sleep mode;

[0078] Comparing the current time to the scheduled start time using the real-time clock in the power control module; and

[0079] Switches the power control module from sleep mode to wake mode and automatically powers on the AGV from the off state when the current time has a predetermined necessary relationship to the scheduled start time.

[0080] The switching step may further include automatically powering on a wireless communication device on the AGV and establishing a wireless communication connection between the AGV and a facility supervisory system at the facility where the AGV is located.

[0081] The predetermined necessary relationship for determining whether to power on the AGV can be, for example, that the current time is equal to the scheduled start time. Alternatively, it can be some other relationship, such as starting the AGV before the scheduled start time, or delaying the shutdown to a certain amount of time after the end of the shift. Because the wake-up circuit 62 can communicate with the PLC 42 at least indirectly (e.g., via the FSS 12) via the Modbus and Profinet buses, it can provide a command to the PLC 42 at the appropriate time to automatically shut down the AGV 16 via relay CR2. Alternatively, the PCM 60 can include additional circuitry (e.g., another relay 78 that controls another control output) placed in series with the AGV-OFF ​​switch and the CR2-1 contact to implement direct shutdown control by the PCM 60.

[0082] The PCM 60 may also include a charging circuit 90 that receives 24V power from the dc-dc converter 46 via the AGV startup circuit output 56 and supplies this voltage to the auxiliary battery 64 through the relay C of the wake-up circuit 62. The charging circuit 90 may include a low-ohm, high-wattage resistor to provide a trickle charge to the battery 64. Control of the relay C may be performed by the wake-up circuit using a simple op-amp comparator that receives the voltage of the battery 64 as input (using a voltage divider) and a Zener diode-based reference voltage to provide a binary signal back to the wake-up circuit 62, which the CPU 72 uses to energize the relay C when the battery 64 needs to be charged.

[0083] Figure 4 More details of the FSS 12 are depicted, which includes one or more FSS controllers 92 and a wireless interface 94 (e.g., a NIC card and / or router) that the FSS controller(s) 92 use to communicate with the AGVs 16 via the facility wireless access point 32 and the AGV WDC 44. Each controller 92 includes a microprocessor or other electronic processor 95 and computer memory 96, the computer memory including at least one non-transitory computer-readable medium having stored thereon a main program 97 and an integrated or separate AGV supervisory control program (SVP) 98. Both programs include computer-readable instructions and are accessible by the processor 95 for execution. The SVP 98 operates to receive AGV commands (e.g., start, shut down) and AGV parameters including sleep mode duration, wake mode duration, and shift schedule, and converts this information into commands and parameters used by the wake-up circuit 62 discussed above. This can be done individually for each AGV within the fleet 14, or can be done globally for all AGVs as needed or desired. SVP 978 may also receive status and other data supplied by wake-up circuit 62. The programming and use of SVP 98 will be apparent to those skilled in the art.

[0084] It should be understood that the foregoing description is a description of one or more embodiments of the present invention. The present invention is not limited to the specific embodiment(s) disclosed herein, but is limited only by the following claims. In addition, the statements contained in the foregoing description relate to the disclosed embodiment(s) and should not be interpreted as limiting the scope of the present invention or the definition of the terms used in the claims, unless a term or phrase is clearly defined above. Various other embodiments and various modifications to the disclosed embodiment(s) will become apparent to those skilled in the art. For example, in other embodiments, the timer circuit can be implemented in a manner other than using a real-time clock, an electronic processor, or a digital counter, such as by using a 555 timer. Moreover, the PCM 60 can be powered by the main AGV battery 48 or some other power source instead of using the auxiliary battery 64. It should be understood that the functions of the PCM 60 and / or the AGV electronic device 40 can also be implemented via alternative circuit topologies and / or by using different electrical components with respect to the embodiment(s) discussed above. For example, in some embodiments, the relay can be replaced by an electronic (e.g., transistor-based) switch. All such embodiments and modifications are intended to fall within the scope of the present invention.

[0085] As used in this specification and claims, the terms "e.g.," "for example," "for instance," "such as," and "like," and the verbs "comprising," "having," "including," and their other verb forms, when used in conjunction with a list of one or more components or other items, are each to be interpreted as open-ended, meaning that the list should not be construed to exclude other additional components or items. Other terms are to be interpreted using their broadest reasonable meaning unless they are used in a context that requires a different interpretation. In addition, the term "and / or" should be interpreted as an inclusive or. Thus, for example, the phrase "A, B, and / or C" should be interpreted to cover all of the following: "A"; "B"; "C"; "A and B"; "A and C"; "B and C"; and "A, B, and C."

Claims

1. An automatic guided vehicle (AGV) power control module, comprising: a wake-up circuit having at least one command input and at least one control output and operable by power received from a power source; The wake-up circuit includes a timer circuit and at least one parameter that can be configured via the command input, and the timer circuit is coupled to the control output to change the output state of the control output according to the parameter.

2. The AGV power control module according to claim 1, wherein: The timer circuit executes a sleep / wake cycle with the control output being set to a first state during a sleep portion of the cycle and to a different second state during a wake portion of the cycle, and wherein the parameter is a sleep time parameter indicative of a duration of the sleep portion of the cycle.

3. The AGV power control module according to claim 2, wherein: The timer circuit includes a wake-up time parameter indicating a duration of the wake-up portion of the cycle.

4. The AGV power control module according to claim 2, wherein: The second state of the control output includes power sufficient to operate a wireless communication device (WCD).

5. The AGV power control module according to claim 4, wherein: The control output includes a WCD power output, and wherein the wake-up circuit further includes a second control output, the second control output including an AGV power output capable of switching between a first state and a second state, the second state providing power sufficient to operate the AGV startup circuit, and wherein the wake-up circuit operates during the sleep portion of the cycle to maintain the WCD power output and the AGV power output in their first state, during which the power provided by the WCD power output and the AGV power output is insufficient to activate the WCD or the AGV startup circuit, respectively.

6. The AGV power control module according to claim 5, wherein: The wake-up circuit operates during a wake-up portion of the cycle to set the WCD power output to its second state, monitor the command input for an AGV start command, and set the AGV power output to its second state upon receipt of the AGV start command.

7. The AGV power control module according to claim 1, wherein: The wake-up circuit further includes a relay that switches an output state of the control output between a first state and a second state based on one or more commands received via the command input.

8. The AGV power control module according to claim 1, further comprising an AGV startup circuit input and an AGV startup circuit output, wherein: The control output of the wake-up circuit and the AGV start circuit output are connected together to the AGV start circuit input in a logical OR manner, so that the power signal on either or both of the control output and the AGV start circuit output causes the power control module to output a power signal on the AGV start circuit input.

9. The AGV power control module according to claim 8, wherein: The wake-up circuit control output and the AGV start circuit output are connected together in a logical OR manner using a diode.

10. The AGV power control module according to claim 1, wherein: The at least one command input comprises a multi-wire bus interface, and the at least one parameter comprises a plurality of time / date parameters stored in the wake-up circuit and configurable via the bus interface.

11. The AGV power control module according to claim 10, wherein: The timer circuit includes a software controlled electronic processor and a real time clock, which can be controlled by the electronic processor. The sub-processor is set using the time / date parameters, and wherein the wake-up circuit comprises a plurality of registers, each register being accessible by the electronic processor and each register storing one of the time / date parameters.

12. The AGV power control module according to claim 1, wherein: The wake-up circuit operates in any of a plurality of operating modes including a sleep / wake-up mode and a shift schedule mode, wherein the wake-up circuit is capable of switching between the operating modes according to a mode command received via the command input, and wherein the wake-up circuit is configured to receive an output control command via the command input and to change an output state of the control output based on the output control command independent of the operating mode.

13. An AGV comprising the power control module according to claim 1.

14. An AGV fleet system, comprising: a plurality of AGVs, each of the plurality of AGVs comprising the AGV of claim 13; as well as A non-transitory computer-readable medium having an AGV supervisory control program stored thereon, the AGV supervisory control program being executable by one or more electronic processors of a facility supervisory system (FSS) to perform an AGV supervisory process, the AGV supervisory process being used to communicate with and control the AGV via wireless communications from the FSS, wherein the AGV supervisory program enables the FSS to communicate with a wake-up circuit of each AGV via an AGV wireless communication device, thereby starting the AGV from a power-off state.

15. An automated guided vehicle (AGV) fleet system comprising: a plurality of AGVs, each AGV having one or more power supplies, a plurality of motors for driving and steering the AGV, a wireless communication device, a wake-up circuit, and an AGV controller, the AGV controller being operable with power from the power supply(s) and coupled to: (i) the motors to control movement and steering of the AGV, (ii) the wireless communication device for communicating with the AGV, and (iii) the wake-up circuit for wirelessly starting the AGV; and A non-transitory computer-readable medium having an AGV supervisory control program stored thereon, the AGV supervisory control program being executable by one or more electronic processors of a facility supervisory system (FSS) to perform an AGV supervisory process, the AGV supervisory process being used to communicate with and control the AGV via wireless communications from the FSS, wherein the AGV supervisory program enables the FSS to communicate with a wake-up circuit of each AGV via the AGV wireless communication device, thereby starting the AGV from a power-off state.

16. An automated guided vehicle (AGV) fleet system comprising: a plurality of AGVs located within a facility, each AGV having one or more power sources, a plurality of motors for driving and steering the AGV, a wireless communication device, a wake-up circuit, and an AGV controller operable with power from the power source(s) and coupled to: (i) the motors to control movement and steering of the AGV, (ii) the wireless communication device for communicating with the AGV, and (iii) the wake-up circuit for wirelessly activating the AGV; and A facility supervision system (FSS), the FSS comprising one or more FSS controllers, the one or more FSS controllers comprising an electronic processor and a memory accessible by the processor, the memory storing software comprising instructions executable by the electronic processor to perform an AGV supervision control process for communicating with and controlling the AGVs, the FSS further comprising a plurality of wireless access points distributed around the facility and connected to the (plurality) FSS controllers, wherein the FSS controllers operate under the control of the software to communicate with a wake-up circuit of each AGV via the AGV wireless communication device and one or more of the wireless access points.

17. A method of operating an automated guided vehicle (AGV), the method comprising: operating a power control module of the AGV in a sleep mode; switching from the sleep mode to the wake-up mode by generating a wake-up signal; automatically powering on a wireless communication device on the AGV in response to the wake-up signal while maintaining the AGV in a powered-down state; monitoring for a start command wirelessly received by the wireless communication device; as well as When the start command is received during the monitoring period, the AGV is automatically powered on.

18. The method of claim 17, wherein: The operating step further includes operating the power control module in the sleep mode for a first time period, and wherein the monitoring step further includes monitoring the start command during a second time period after the wake signal.

19. The method of claim 18, further comprising automatically powering off the wireless communication device and returning to the sleep mode when the start command is not received during the second time period.

20. The method of claim 19, further comprising performing a repeating cycle of alternating operating in the sleep mode for the first period of time and operating in the wake mode for the second period of time until the start command is received and the AGV is powered on.

21. The method of claim 18, wherein: The operation steps further include: a processor for operating the power control module in a low-power sleep mode; operating the timer circuit for said first period of time; and Upon expiration of the first time period, the processor is brought out of the low power sleep mode by sending an interrupt from the timer circuit to the processor.

22. The method of claim 17, wherein: The switching step includes switching to the wake-up mode based on a shift schedule start time and a current time provided by a real-time clock on the AGV.

23. A method of operating an automated guided vehicle (AGV), the method comprising: When the AGV is in the off state, operating a power control module of the AGV in a sleep mode; comparing the current time with the scheduled start time using a real-time clock in the power control module; as well as The power control module is switched from the sleep mode to the awake mode and the AGV is automatically powered on from the off state when the current time has a predetermined required relationship to the scheduled start time.

24. The method of claim 23, wherein: The predetermined necessary relationship is that the current time is equal to the planned start time.

25. The method of claim 23, wherein: The switching step further includes automatically powering on a wireless communication device on the AGV and establishing a wireless communication connection between the AGV and a facility supervisory system at the facility where the AGV is located.

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