Automated guided vehicle equipped with a wake-up circuit

Abstract

A facility monitoring system and an automated guided vehicle (AGV) fleet system having a plurality of AGVs, each AGV having a power control module including a wake-up circuit having at least one command input and at least one control output and operable with power received from a power source, the wake-up circuit including a timer circuit and one or more parameters configurable via the command input, the timer circuit coupled to the control output for changing an output state of the control output in response to the parameter.

Description

[Technical Field]

[0001] The present invention relates to an automated guided vehicle (AGV) having a wireless communication function. [Background technology]

[0002] AGVs are used in commercial and industrial facilities to move parts and inventory between physical locations within the facility. They typically include onboard (battery) power and steering systems, enabling autonomous navigation using any of a number of known technologies. Some AGVs also include wireless communication devices (WCDs), which allow the AGV to be commanded and / or polled by a computer monitoring system, typically located within the same facility. Most AGVs in use today do not operate 24 hours a day, but rather operate according to work shifts that may be dictated by other parts of the manufacturing or inventory control process, particularly those involving human workers. As a result, AGVs in these situations are manually powered on at the start of each shift or daily cycle and then manually powered off at the end of that shift or cycle. This can be accomplished using a power switch, which, when pressed, provides operating power from the AGV's main battery to its circuits and keeps that operating power on using a relay or other means until the AGV is shut down by operating the power switch or other button. The AGV 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 [Means for solving the problem]

[0003] According to one aspect of the present invention, an automated guided vehicle (AGV) power control module is provided, comprising a wake-up circuit having at least one command input and at least one control output, operable with power received from a power source, the wake-up circuit including a timer circuit and at least one parameter settable via the command input, the timer circuit coupled to the control output for changing an output state of the control output in response to the parameter.

[0004] In various embodiments, the AGV power control module may include one or more of the following features, either alone or in any technically feasible combination: The timer circuit implements a sleep / wake cycle, wherein the control output is set to a first state during a sleep portion of the cycle and to a second, different state during a wake portion of the cycle, the parameter being a sleep time parameter indicating the length of time of the sleep portion of the cycle. The timer circuit includes a wake time parameter that indicates the length of time for the wake portion of the cycle. The second state of the control output includes sufficient power to operate a wireless communication device (WCD). - the control output includes a WCD power output, the wake-up circuit further includes a second control output switchable between a first state and a second state and including an AGV power output that provides sufficient power to operate the AGV starting circuitry, and the wake-up circuit operates during the sleep portion of the cycle to hold the WCD power output and the AGV power output in their first state during which they do not provide sufficient power to operate the WCD or AGV starting circuitry, respectively. - The wake-up circuit operates during the wake portion of the cycle to set the WCD power output to its second state, monitor the command input for the presence or absence of an AGV start command, and, if an AGV start command is received, set the AGV power output to its second state. 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. - the AGV power control module further includes an AGV start circuit input and an AGV start circuit output, and the control output of the wake-up circuit and the AGV start circuit output are both logically ORed into the AGV start circuit input, whereby a power signal at either of both the control output and the AGV start circuit output will cause a power signal to be output by the power control module at the AGV start circuit input. - The wake-up circuit control output and the AGV start circuit output are logically ORed together using a diode. The at least one command input includes a multi-wire bus interface, and the at least one parameter includes a plurality of time / date parameters stored within the wake-up circuit and configurable via the bus interface. - the timer circuit includes a software-controlled electronic processor and a real-time clock configurable by the electronic processor with time / date parameters, and the wake-up circuit includes a plurality of registers, each accessible by the electronic processor, each storing one of the time / date parameters. - the wake-up circuit operates in any of a plurality of operating modes including a sleep / wake mode and a shift schedule mode, the wake-up circuit being switchable between the plurality of operating modes by a mode command received via the command input, the wake-up circuit being 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 regardless of the operating mode.

[0005] According to another aspect of the present invention, there is provided an AGV including the above-described power control module.

[0006] According to yet another aspect of the present invention, there is provided an AGV fleet system including a plurality of AGVs and a non-transitory computer readable medium having stored thereon an AGV monitoring control program executable by one or more electronic processors of a facility monitoring system (FSS) and performing an AGV monitoring process for communicating with and controlling the AGVs via wireless communication from the FSS, the AGV monitoring program causing the FSS to communicate with wake-up circuitry of each AGV via the AGV wireless communication equipment, thereby starting the AGV from a powered-down state.

[0007] Yet another aspect of the present invention provides an automated guided vehicle (AGV) fleet system including a plurality of AGVs, each AGV having one or more power sources, a plurality of motors for driving and steering the AGV, wireless communication equipment, a wake-up circuit, and an AGV controller operable with power from the power sources, the AGV controller (i) coupled to the motors to control movement and steering of the AGV, (ii) coupled to the wireless communication equipment for communication to and from the AGV, and (iii) coupled to the wake-up circuit for wireless start-up of the AGV; and a non-transitory computer-readable medium having stored thereon an AGV monitoring control program executable by one or more electronic processors of a facility monitoring system (FSS) to perform an AGV monitoring process for communicating with and controlling the AGVs via wireless communication from the FSS, the AGV monitoring program causing the FSS to communicate with the wake-up circuit of each AGV via the AGV wireless communication equipment, thereby starting the AGV from a power-down state.

[0008] In yet another aspect of the present invention, an automated guided vehicle (AGV) fleet system is provided, comprising: a plurality of AGVs disposed within a facility, each AGV having one or more power sources, a plurality of motors for driving and steering the AGV, wireless communication equipment, a wake-up circuit, and an AGV controller operable with power from the power source and (i) coupled to the motors to control movement and steering of the AGV, (ii) coupled to the wireless communication equipment for communication to and from the AGV, and (iii) coupled to the wake-up circuit for wireless initiation of the AGV; a facility monitoring system (FSS) including one or more FSS controllers that include an electronic processor and memory accessible by the processor, the memory storing software executable by the electronic processor to execute an AGV supervisory control process for communication and control of the AGVs; and the FSS further including a plurality of wireless access points distributed within the facility and connected to the FSS controllers, the FSS controller operative under control of the software to communicate with the wake-up circuit of each AGV via one or more of the AGV wireless communication equipment and the wireless access points.

[0009] Yet another aspect of the present invention relates to a method of operating an automated guided vehicle (AGV), comprising the steps of: operating a power control module of the AGV in a sleep mode; switching from the sleep mode to a wake mode by generating a wake-up signal; automatically powering on wireless communication equipment on the AGV in response to the wake-up signal while maintaining the AGV in a shutdown state; monitoring for a start command received wirelessly by the wireless communication equipment; and automatically powering on the AGV if a start command is received during monitoring.

[0010] In various embodiments, the method may include one or more of the following features, either alone or in any technically feasible combination: The operating step further includes operating the power control module in a sleep mode for a first period of time, and the monitoring step further includes monitoring for the presence or absence of a start-up command during a second period of time after the wake-up signal. The method further includes automatically powering down the wireless communication device and returning it to a sleep mode if no wake-up command is received during the second period of time. The method further includes performing a repeated cycle of alternating operation in a sleep mode for a first period of time and in a wake mode for a second period of time until a start command is received and the AGV is powered on. the operating step further includes operating a processor of the power control module in a low power sleep mode; operating the timer circuit for a first period of time; and, at the end of the first period of time, switching the processor out of the low power sleep mode by sending an interrupt signal from the timer circuit to the processor. The switching step includes switching to a wake mode based on a shift schedule start time and a current time provided by a real-time clock on the AGV.

[0011] In yet another aspect of the present invention, a method for operating an automated guided vehicle (AGV) is provided, the method including: operating a power control module of the AGV in a sleep mode while the AGV is in a shutdown 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 a wake mode and automatically powering on the AGV from the shutdown state when the current time has a predetermined required relationship with the scheduled start time. In at least some embodiments, the predetermined required relationship is that the current time is equal to the scheduled start time. The switching step can further include automatically powering on wireless communication equipment on the AGV and establishing a wireless communication connection between the AGV and a facility monitoring system at the facility where the AGV is located.

[0012] Preferred exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which like numerals refer to like elements, and in which: [Brief explanation of the drawings]

[0013] [Figure 1] 1 illustrates a schematic diagram of a facility having a facility monitoring system (FSS) and a fleet of automated guided vehicles (AGVs), all configured in accordance with an embodiment of the present invention. [Figure 2] FIG. 2 is an electronic circuit diagram of one of the individual AGVs of FIG. 1, including a wake-up circuit that forms part of the power control module for that AGV. [Figure 3] 3 is a list of addressable registers of the wake-up circuit of FIG. 2 used to hold command, parameter, and status information. [Figure 4] 2 is a schematic diagram of the facility monitoring system of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0014] Referring to FIGURE 1, a facility 10 is shown schematically having a facility monitoring system (FSS) 12 and a fleet 14 of individual automated guided vehicles (AGVs) 16. In general operation, the fleet 14 of AGVs 16, coordinated by the FSS 12, operates during any particular work shift to move materials, inventory, and / or work-in-progress between different locations within the facility. One common such application is moving work-in-progress parts between various work stations, for which the AGVs may include tooling and / or movable platforms powered by scissor lifts, rigid chains, hydraulic systems, etc., as known to those skilled in the art.

[0015] Each AGV 16 includes the basic components of a typical AGV, such as a body 18 covering a chassis supporting a plurality of wheels 20, including one or more steered wheels, and one or more servo motors 24 ( FIG. 2 ) used to steer and drive the AGV's wheels 20. Various techniques for guiding and controlling the path of an AGV 16 are known to those skilled in the art, including, for example, in-floor wire tracking and magnetic strip tracking, as taught in U.S. Pat. No. 8,751,142 B2. Each AGV 16 also includes at least one control panel 26 containing a human-machine interface (HMI) 28 ( FIG. 2 ) and one or more antennas 30 for wireless communication between the AGV and the FSS 12. To that end, the FSS 12 has at least one, but typically multiple, wireless access points 32 spaced throughout the facility 10 near the fleet 14.

[0016] As will be described in more detail with respect to Figure 2, each of the AGVs 16 further includes AGV electronics that enable the AGV to achieve its desired functionality and operational capabilities. The construction and integration of the basic AGV components described above with respect to Figure 1 is known to those skilled in the art.

[0017] 2 shows a schematic representation of AGV 16, which includes AGV electronics 40 and a power control module (PCM) 60 that provide AGV 16 with improved capabilities over typical AGVs currently used in manufacturing and inventory operations. The components and circuitry that include AGV electronics 40 are shown to the right of the dashed line in FIG. 2, and the components and circuitry that include power control module 60 are shown to the left of the dashed line.

[0018] The AGV electronics 40 includes as its primary electrical components an AGV programmable logic controller (PLC) 42, which provides the overall control and operation of the AGV, as well as a wireless communication device (WCD) 44 with an antenna 30 for communication between the PLC 42 and the FSS 12. On-board power is provided by a 24v dc-dc converter 46, which obtains its input power from a 48v dc battery supply 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 supply from the dc-dc converter 46 as needed or desired for other portions of the AGV electronics 40.

[0019] AGV PLC 42 may be any suitable programmable logic controller, such as those known for AGVs. Similarly, WCD 44 may be a network-enabled Wifi client module using 802.11 protocol and a wired Ethernet connection for communication with access point 32 of FSS 12. For example, WCD 44 may be implemented using a Siemens™ SCALANCE W700 series client module. WCD 44 is connected to PLC 42 using a wired bus and a bus protocol such as PROFINET.

[0020] Aside from PLC 42, each of the other major components of AGV electronics 40 is addressable from FSS 12 via WCD 44, e.g., using a different fixed IP address for each component. This can include HMI 28, WCD 44 itself, as well as other circuitry not explicitly shown in FIG. 2, such as each of the multiple magnetic sensor boards that may be included when using the guidance system of the aforementioned U.S. Patent No. 8,751,142 B2.

[0021] AGV startup and shutdown are accomplished using an AGV operating power control circuit that employs relay logic, depicted using distributed schematic symbols, within AGV electronics 40. The AGV operating power control circuit includes an AGV startup circuit 50 and an AGV shutdown circuit 52. Start circuit 50 includes a normally-open (NO) momentary power switch, AGV-ON, and a first control relay having an energized coil CR1 that controls three separate NO contact pairs, CR1-1, CR1-2, and CR1-3. Shutdown circuit 52 includes a normally-closed (NC) power disconnect switch, AGV-OFF, as well as a second control relay operated by PLC 42 with an energized coil CR2 that controls one NC contact pair, CR2-1.

[0022] The basic operation of the start circuit 50 is as follows: At the beginning of a work shift, an operator operates the momentary switch AGV-ON, thereby connecting 48v battery power to the dc-dc converter 46, which then generates its 24v dc output, which is supplied 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 ​​in the shutdown circuit 52 can be connected to the input of relay coil CR1, as shown by the dashed line. Because both shutdown components CR2-1 and AGV-OFF ​​use normally closed contacts, 24v power is connected through them to relay coil CR1, which energizes the coil and closes three separate pole groups: contacts CR1-1, CR1-2, and CR1-3. This has the effect of latching power on, as contact CR1-1 (which is currently closed) shunts power through the momentary switch AGV-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, provide its 24v output power, and activate coil CR1 is on the order of milliseconds, typically much less than one second, allowing the AGV-ON switch to mimic the response of a latching switch, as well as allowing for electronic shutdown of the AGV. This basic operation of the start circuit 50 (power supplied to CR1 via the dashed connection) allows only manual operation of the start via switch AGV-ON.

[0023] Shutdown of the AGV 16 can be accomplished manually by switch AGV-OFF, or electronically by the PLC 42 energizing relay coil CR2. Pressing the AGV-OFF ​​switch interrupts the 24v power supply energizing relay coil CR1, which opens contact CR1-1 and stops power flow from the battery 48 to the dc-dc converter 46. As a result, when the AGV-ON switch is released, coil CR1 no longer receives energized power. Contact CR1-2 also returns to its normally open position, terminating power to the motor 24. Thus, the AGV 16 is de-energized. Shutdown can also be accomplished similarly using the PLC 42. When relay coil CR2 is activated by the PLC 42, contact CR2-1, in series with the AGV-OFF ​​switch, opens, thus having the same effect of de-energizing the dc-dc converter 46; when coil CR2 is de-energized, relay coil CR1 de-energizes, and contact CR2-1 returns to its normally closed state.

[0024] According to the illustrated embodiment of the invention, PCM 60 is connected to AGV electronics 40, thereby enabling electronically controlled starting of AGV 16, i.e., without the need to manually operate switch AGV-ON. This is accomplished by eliminating the dashed connection between switch AGV-OFF ​​and relay coil CR1 in shutdown circuit 52, and instead providing start circuit 50 with an AGV start circuit input 54 and an AGV start circuit output 56, which are used by PCM 60 to enable both manual start via switch AGV-ON and automatic start via PCM 60. Via AGV start circuit input 54, PCM 60 can provide an activation or power signal to AGV electronics 40, which will turn on the AGV, similar to manually operating the AGV-ON switch. As described in more detail below, the start signal can be generated by PCM 60 automatically, for example, at a specific time or after a predetermined time interval, or when commanded by FSS 12.

[0025] The PCM 60 includes a wake-up circuit 62 that is powered by a 24v auxiliary battery 64. The wake-up circuit 62 includes a group of 24v relay switch control outputs, including an AGV power output 66 that generates an AGV_ON signal and is logically ORed with the AGV start circuit output 56, so that a 24v power signal on either or both of the AGV power output 66 and the AGV start circuit output 56 causes a power signal to be output by the PCM 60 to the AGV start circuit input 54. As previously mentioned, this power signal in turn energizes the relay coil CR1, thereby closing contacts CR1-1 and CR1-2, thereby providing operating power to the motor 24 and the remainder of the AGV electronics via the dc-dc converter 46. As shown in FIG. 2, this OR-tying of the 24v signal line 56 emanating 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 their cathodes connected to the wake-up circuit control output and the AGV start circuit output, respectively, and to each other at the input of relay coil CR1.

[0026] The start circuit input 54 and output 56 may be implemented physically, as shown with the PCM 60 physically separate from the AGV electronics 40, or may be implemented logically, where the PCM 60 and the AGV electronics 40 are physically integrated, for example, by logically utilizing a dashed connection with relay coil CR1 as the start circuit output 56 and inserting a steering diode 70 in series with that connection.

[0027] This ORing of the control inputs to relay coil CR1 enables wake-up circuit 62 to start AGV 16 via one of its control outputs, specifically AGV power output 66, to which signal AGV_ON is provided. In the illustrated embodiment, this automatic AGV start is accomplished using timer circuit 75, either by using a cyclic sleep / wake mode or by implementing a shift schedule-based process, as will be further described below. In other embodiments, automatic start may also be accomplished using a simpler timer circuit operating in response to a single configurable parameter, which may be, for example, a specified time during which the wake-up circuit operates in sleep mode. When this time expires, PCM 60 wakes up and changes the output state of at least one of its control outputs (e.g., AGV_ON at output 66 or WCD_ON at output 84), thereby either directly initiating AGV start or waking up only WCD 44, which specifies from FSS 12 whether to start AGV 16 or return it to sleep mode. The sleep time parameter may be set by FSS 12 and transmitted to the wake-up circuitry via WCD 44 .

[0028] To enhance functionality, the wake-up circuit 62 includes additional components and circuitry beyond the automatic start-up of the AGV 16 described above. It utilizes a central processing unit (CPU) 72 and a real-time clock (RTC) 74, which collectively form a timer circuit 75. The wake-up circuit 62 further includes an I / O controller 76, an opto-isolator 77, a relay 78, and registers 80 that 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 or other suitable Ethernet cable, that connects 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 command inputs through which commands are received, as well as parameters used by the wake-up circuit to perform its functions. It can also be used to provide status information to or from the wake-up circuit to the FSS 12 or PLC 42. In other embodiments, the command inputs 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 circuitry receives command and / or parameter data, and those skilled in the art will appreciate that these input commands and / or parameters may be processed and used to activate control outputs of the wake-up circuitry using a processor such as CPU 72, or using a gate array, or simply using relay logic.

[0029] The functionality of wake-up circuit 62 may be implemented under the control of CPU 72 using a program stored in the CPU's internal flash memory. A suitable CPU may be a PIC32MX274F256BT-V / MM available from Microchip Technology Inc. The programming of CPU 72 required for wake-up circuit 62 will be apparent to those skilled in the art from the following functional description of the operation of circuit 62.

[0030] The wake-up circuit 62 operates during shutdown of the AGV 16, e.g., between work shifts. It operates to enable the AGV to automatically start upon command or according to a schedule. To this end, it operates in a low-power sleep mode from the auxiliary battery 64 during AGV shutdown, and then periodically (using a fixed or variable time interval) checks for a start command from the FSS 12 or wakes up at a set time depending on the AGV's scheduled start. To this end, the wake-up circuit 62, and thus the PCM 60 itself, can operate in either of two operating modes: a periodic (or cyclical) sleep / wake mode and a shift schedule mode. In the sleep / wake mode, the wake-up circuit 62 uses a timer circuit 75, including the CPU 72 and RTC 74, to execute a periodic sleep / wake cycle that alternates between sleep and wake modes. These sleep and wake modes are manifested by two different output states at the wake-up circuit 62's control outputs (e.g., outputs 66 or 84). The output state has a first state in sleep mode (e.g., 0 volts or high impedance) and a different second state in wake mode (e.g., a low impedance 24v power supply signal). Wake-up circuit 62 continues to alternate between sleep and wake modes until a command is received to start AGV 16 during wake mode. When this command is received, circuit 62 responds by stopping the sleep / wake mode cycle and powering up AGV 16. This mode uses at least two parameters: a sleep time parameter indicating a first length of time that it will operate in sleep mode, and a wake time parameter indicating a second length of time that it will operate in wake mode. These parameters are defined and stored in timer circuit 75 (e.g., in CPU 72 or RTC 74).

[0031] In shift schedule mode, timer circuit 75 uses RTC 74 to switch from sleep mode to wake mode at a specific date and time stored in RTC 74. A suitable real-time clock is the RV5C387A-E2-F available from Ricoh™ and others. CPU 72 may also access the current time from RTC 74 for various other purposes, such as identifying upcoming shutdown times for AGVs according to a shift schedule. Resetting clock 74 to the current date may also be programmatically performed by CPU 72, for example, periodically using date and time information from an online NIST or other time server.

[0032] Looking more specifically at wake-up circuit 62, data and command communication occurs via Modbus TCP terminal server 82. Commands and parameters sent from WCD 44 to wake-up 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 lists exemplary addressable registers 80 for commands and parameters as well as status information that can be returned from wake-up circuit 62. Thus, for example, sleep time and wake time parameters can be provided from FSS 12 to registers 40014 and 40015, which are then read and used by CPU 72. The sleep time parameter may be used by the CPU 72 to configure the RTC 74 to provide a periodic interrupt signal to the CPU 72 every xxx seconds when the PCM 60 is in sleep / wake mode, where xxx is the sleep time parameter (and thus the length of the first time period). The second time period (i.e., the wake time parameter) may also be used by the RTC 74 to indicate that the wake time has expired, or by the CPU 72 to determine that the wake time has expired after exiting sleep mode. In other embodiments, one or both of these parameters are hard-coded into the wake-up circuitry and cannot be changed thereafter.

[0033] Similarly, in the shift schedule mode of operation, the date and time for starting AGV 16 can be specified by FSS 12 using some or all of registers 40008-40013, and CPU 72 can configure RTC 74 to generate an alarm (e.g., a CPU interrupt signal) when the specified date and time is reached. This advantage of using a real-time clock for the timer circuit allows AGV 16 to automatically wake up on schedule if it loses power completely and is unable to communicate remotely.

[0034] In addition to providing parameter data, the PLC 42 and / or FSS 12 can provide commands to directly control the operating mode and control outputs 66, 84, 86 of the wake-up circuit 62. This can be done by assigning some of the available registers 80 as command registers for receiving mode and start commands. The operating mode can be set using register address 40017, and the control outputs 66, 84, 86 can be switched between their two output states (0 or 24v) using register address 40018 by identifying the desired associated relay 78 (relay A, B, or C, respectively) and the desired state (OFF or ON). As will be appreciated, this forced control output state change can be performed regardless of the operating mode (sleep / wake mode or shift schedule mode), thereby allowing the AGV 16 to be remotely started regardless of the current state of the wake-up circuit 62.

[0035] Available registers 80 can also be designated as status indicators. For example, register 40016 is used to return the AGV operating status (either powered off or powered on). This AGV status is obtained from opto-isolator 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 status and provide it back to the PLC 42 and / or FSS 12.

[0036] These data and commands to / from the wake-up circuit 62 via Modbus TCP terminal server 82 are moved in and out of registers 80 by CPU 72. As will be appreciated by those skilled in the art, I / O controller 76 is used by the CPU to write to and read from various input / output devices (i.e., opto-isolators 77 and relays 78). The wake-up circuit 62 may also include a status LED 88 operated by CPU 72 via I / O controller 76 to indicate the operational status of the wake-up circuit 62 as well as any desired diagnostic information that may be obtained from the wake-up circuit.

[0037] Relays A and B of wake-up circuit 62 control the states of control outputs 84 and 66, respectively. Because these relays switch 24v power from auxiliary battery 64, they provide sufficient power for WCD 44 and start-up circuit 50. As shown in FIG. 2, WCD 44 can receive 24v operating power separately from both dc-dc converter 46 and auxiliary battery 64 via relay A. In the case of the aforementioned Siemens™ SCALANCE W700 series wireless communication device, this can be done using both its primary and auxiliary power inputs. For other WCD 44 devices that do not have separate power inputs, the two 24v sources can be ORed together using diodes, as described above with respect to start-up circuit 50.

[0038] The use of these two separately controllable outputs 84 and 66 allows for a staged wake-up process in which only a portion of the AGV electronics is initially powered up so that it can monitor for and receive an AGV start command, and if received, automatically execute a full power-up of the AGV. Thus, the wake-up circuit 62 operates during the sleep portion of the cycle (sleep mode) to hold the WCD_ON power output 84 and the AGV_ON power output 66 in their first state (relays A and B open contacts) during which they do not provide enough power to activate the WCD or AGV start circuitry, respectively. The wake-up circuit 62 then operates in the wake portion of the cycle (wake mode) to (i) set the WCD_ON power output 84 to its second state (relay A contacts closed), (ii) monitor the command input for an AGV start command (e.g., using register 40018 to monitor whether DO_FORCE relay B is ON), and (iii) set the AGV power output to its second state when an AGV start command is received.

[0039] This staged start of the AGV can be used in both the sleep / wake and shift schedule modes of operation. By using the AGV 16 with its PCM 60, this staged wake mode: operating a power control module of the AGV in a sleep mode; switching from a sleep mode to a wake mode by generating a wake-up signal; In response to the wake-up signal, automatically powering on wireless communication equipment on the AGV while maintaining the AGV in a shutdown state; monitoring for a start command received wirelessly by the wireless communication device; automatically powering on the AGV if a start command is received during the monitoring step; The method can be implemented by a method including:

[0040] The switching step can be performed using the RTC 74 to generate a wake-up signal as an interrupt signal sent to the CPU 72 when the sleep mode time expires (e.g., after 300 seconds). During sleep mode, the CPU 72 can be placed in its own low-power sleep mode, where it ceases most of its functions until an interrupt signal is received on its designated input pin. An interrupt signal from the RTC 74 to the CPU 72 can therefore switch it from its own low-power mode back to full operation. This allows the AGV electronics 40 to be completely powered down, and the PCM 60 itself to be completely powered down, except for the RTC 74 and any power control devices that are powered by the auxiliary battery 64 required to operate the RTC.

[0041] As previously mentioned, automatically powering on WCD 44 can be accomplished under control of CPU 72 using relay A of the wake-up circuit while keeping relay B in an off state, so that the AGV remains in its shutdown state. Wake-up circuit 62, now operating in wake mode, can then monitor register 80 for a start command received from FSS 12 via WCD 44, and if / when received, CPU 72 can turn on relay B to start AGV 16.

[0042] Additional aspects of this stepwise method will be apparent from the above description of the illustrated embodiment. For example, the method may include any of the following additional features: The operating step further includes operating the power control module in a sleep mode for a first period of time, and the monitoring step further includes monitoring for the presence or absence of a start-up command during a second period of time after the wake-up signal. The method further includes automatically powering down the wireless communication device and returning it to a sleep mode if no wake-up command is received during the second period of time. The method further includes performing a repeated cycle of alternating operation in a sleep mode for a first period of time and in a wake mode for a second period of time until a start command is received and the AGV is powered on. The operation steps are: - operating the electronic processor of the power control module in a low-power sleep mode; - operating a timer circuit for a first period of time; - switching the electronic processor out of the low power sleep mode by sending an interrupt signal from the timer circuit to the electronic processor at the end of the first time period; Further includes: The step of switching includes switching to a wake mode based on a shift schedule start time and the current time provided by a real time clock on the AGV.

[0043] In the shift schedule operation mode, the AGV does not need to use the staged start-up process and can be started using the following methods: The AGV's power control module operates in sleep mode while the AGV is in shutdown state, comparing the current time with the scheduled start time using a real-time clock in the power control module; The power control module is switched from a sleep mode to a wake mode to automatically power on the AGV from a shutdown state when the current time has a predetermined required relationship with the schedule start time.

[0044] The switching step may further include automatically powering on wireless communication equipment on the AGV and establishing a wireless communication connection between the AGV and a facility monitoring system for the facility in which the AGV is located.

[0045] The predetermined required relationship used to determine 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 shutdown until a certain time has passed since the end of the shift. Because the wake-up circuit 62 can communicate at least indirectly (e.g., via the FSS 12) with the PLC 42 via the Modbus and Profinet buses, it can provide a timely command to the PLC 42 to automatically shut down the AGV 16 via relay CR2. Alternatively, the PCM 60 can include additional circuitry (e.g., another relay 78 controlling another control output) in series with the AGV-OFF ​​switch and the CR2-1 contact, thereby allowing direct shutdown control by the PCM 60.

[0046] The PCM 60 may also include a charging circuit 90, which receives 24v power from the dc-dc converter 46 via the AGV start circuit output 56 and supplies this voltage to the auxiliary battery 64 through relay C in the wake-up circuit 62. The charging circuit 90 may include a low resistance, high wattage resistor to provide a trickle charge to the battery 64. Control of relay C may be performed by the wake-up circuit using a simple op-amp comparator and zener diode reference voltage that receives the battery 64 voltage as an input (using a voltage divider), thereby providing a battery signal back to the wake-up circuit 62, which is used by the CPU 72 to energize the relay when the battery 64 needs charging.

[0047] FIG. 4 shows a more detailed portion of the FSS 12, which includes one or more FSS controllers 92 and a wireless interface 94 (e.g., a NIC card and / or router) used by the FSS controllers 92 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, which includes at least one non-transitory computer-readable medium having thereon a main program 97 as well as an integrated or separate AGV supervisory control program (SVP) 98. Both programs contain computer-readable instructions that the processor 95 can access and execute. The SVP 98 operates to receive AGV commands (e.g., start, shutdown) as well as AGV parameters, including sleep mode duration, wake mode duration, and shift schedule, and to convert that information into the aforementioned commands and parameters used by the wake-up circuitry 62. This can be done individually for each AGV in the fleet 14 or collectively for all AGVs as needed or desired. SVP 978 may also receive status and other data provided by wake-up circuitry 62. Programming and use of SVP 98 will be apparent to those skilled in the art.

[0048] It should be understood that the foregoing description relates to one or more embodiments of the present invention. The present invention is not limited to the specific embodiments disclosed herein, but is defined solely by the claims that follow. Furthermore, statements contained within the above description relate to the disclosed embodiments and should not be construed as limitations on the scope of the invention or on the definition of terms used in the claims unless those terms or phrases are expressly defined above. Various other embodiments and modifications to the disclosed embodiments will be apparent to those skilled in the art. For example, in other embodiments, the timer circuit may be implemented in ways other than using a real-time clock, an electronic processor, or a digital counter, such as a 555 timer. Also, rather than using an auxiliary battery 64, the PCM 60 may be powered by the main AGV battery 48 or any other power source. It should be understood that the functionality of the PCM 60 and / or the AGV electronics 40 may be implemented through alternative circuit topologies and / or through the use of different electrical components relative to the foregoing embodiments. For example, in certain embodiments, relays may be replaced with electronic (e.g., transistor-based) switches. All such embodiments and modifications are intended to be within the scope of the present invention.

[0049] As used in this specification and claims, the terms "e.g.," "for example," "for instance," "such as," "like," and the verbs "comprising," "having," and "including" and other forms of these verbs, when used in conjunction with a list of one or more components or other items, are each to be construed as open-ended, meaning that the list is not to be understood as excluding other, additional components or items. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context requiring a different interpretation. Additionally, the term "and / or" is to be construed as an inclusive disjunction. Thus, for example, the phrase "A, B, and / or C" is to be construed to cover all of the following: "A," "B," "C," "A and B," "A and C," "B and C," and "A and B and C."

Claims

1. In an automated guided vehicle (AGV) power control module, a wake-up circuit having at least one command input and at least one control output, the wake-up circuit being operable with power received from a power source; the wake-up circuit includes a timer circuit and at least one parameter that can be set via the command input, the timer circuit being coupled to the control output to change an output state of the control output in response to the parameter.

2. 2. The AGV power control module of claim 1, wherein said timer circuit implements a sleep / wake-up cycle, wherein said control output is set to a first state during a sleep portion of said cycle and to a second, different state during a wake portion of said cycle, and said parameter is a sleep time parameter indicating a length of time for said sleep portion of said cycle.

3. 3. The AGV power control module of claim 2, wherein said timer circuit includes a wake time parameter indicating a length of time for said wake portion of said cycle.

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

5. 5. The AGV power control module of claim 4, wherein the control output includes a WCD power output, and the wake-up circuit further includes a second control output switchable between a first state and a second state and including an AGV power output that provides sufficient power to operate an AGV starting circuit, and the wake-up circuit operates during the sleep portion of the cycle to hold the WCD power output and the AGV power output in their first states, during which they do not provide sufficient power to operate the WCD or the AGV starting circuit, respectively.

6. 6. The AGV power control module of claim 5, wherein the wake-up circuit operates during the wake 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 when the AGV start command is received.

7. 2. The AGV power control module of claim 1, wherein the wake-up circuit further includes a relay that switches the 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. 2. The AGV power control module of claim 1, further comprising an AGV start-up circuit input and an AGV start-up circuit output, wherein the control output of the wake-up circuit and the AGV start-up circuit output are both logically ORed into the AGV start-up circuit input, whereby a power signal at either of the control output and the AGV start-up circuit output will cause a power signal to be output by the power control module at the AGV start-up circuit input.

9. 9. The AGV power control module of claim 8, wherein the wake-up circuit control output and the AGV start circuit output are logically ORed together using a diode.

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

11. 11. The AGV power control module of claim 10, wherein the timer circuit includes a software controlled electronic processor and a real time clock settable by the electronic processor with the time / date parameters, and the wake-up circuit includes a plurality of registers, each accessible by the electronic processor, each storing one of the time / date parameters.

12. 2. The AGV power control module of claim 1, wherein the wake-up circuit operates in one of a plurality of operating modes including a sleep / wake mode and a shift schedule mode, the wake-up circuit being switchable between the plurality of operating modes by a mode command received via the command input, and the wake-up circuit is configured to receive an output control command via the command input and change the output state of the controlled output based on the output control command regardless of the operating mode.

13. An AGV including the power control module of claim 1.

14. In the AGV fleet system, a plurality of AGVs, each comprising the AGV of claim 13; and a non-transitory computer-readable medium having stored thereon an AGV monitoring and control program executable by one or more electronic processors of a facility monitoring system (FSS) and performing an AGV monitoring process for communicating with and controlling the AGVs via wireless communication from the FSS, the AGV monitoring program causing the FSS to communicate with a wake-up circuit in each AGV via AGV wireless communication equipment, thereby starting the AGV from a powered-down state.

15. In an automated guided vehicle (AGV) fleet system, a plurality of AGVs, each AGV having one or more power sources, a plurality of motors for driving and steering the AGV, wireless communication equipment, a wake-up circuit, and an AGV controller operable with power from the power sources, (i) coupled to the motors to control movement and steering of the AGV, (ii) coupled to the wireless communication equipment for communication to and from the AGV, and (iii) coupled to the wake-up circuit for wireless actuation of the AGV; a non-transitory computer readable medium having stored thereon an AGV monitoring and control program executable by one or more electronic processors of a facility monitoring system (FSS) and performing an AGV monitoring process for communicating with and controlling the AGVs via wireless communication from the FSS; wherein the AGV monitoring program causes the FSS to communicate with the wake-up circuit of each AGV via the AGV wireless communication equipment, thereby starting the AGV from a power-down state.

16. In an automated guided vehicle (AGV) fleet system, 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, wireless communication equipment, a wake-up circuit, and an AGV controller operable with power from the power sources, (i) coupled to the motors to control movement and steering of the AGV, (ii) coupled to the wireless communication equipment for communication to and from the AGV, and (iii) coupled to the wake-up circuit for wireless actuation of the AGV; an automated guided vehicle (AGV) fleet system including: a facility monitoring system (FSS) including one or more FSS controllers including an electronic processor and memory accessible by the processor, the memory storing software executable by the electronic processor and including instructions for executing an AGV monitoring control process for communication and control of the AGVs; and the FSS further including a plurality of wireless access points distributed within the facility and connected to the FSS controllers, the FSS controller operating under control of the software to communicate with the wake-up circuitry of each AGV via the AGV wireless communication equipment and one or more of the wireless access points.

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

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

19. 20. The method of claim 18, further comprising automatically powering down the wireless communication device and returning it to the sleep mode if the wake-up command is not received during the second period of time.

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

21. The operating step includes: operating a processor of the power control module in a low power sleep mode; operating a timer circuit for said first period of time; at the end of the first period of time, switching the processor out of the low power sleep mode by sending an interrupt signal from the timer circuit to the processor; 20. The method of claim 18, further comprising:

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

23. A method for operating an automated guided vehicle (AGV), comprising: operating a power control module of the AGV in a sleep mode while the AGV is in a shutdown state; comparing a current time with a scheduled start time using a real time clock within the power control module; switching the power control module from the sleep mode to a wake mode and automatically powering on the AGV from the shutdown state when the current time has a predetermined required relationship with the schedule start time; A method comprising:

24. 24. The method of claim 23, wherein the predetermined required relationship is that the current time is equal to the scheduled start time.

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

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