JP2019168955A - Forklift and controller thereof - Google Patents

Abstract

To provide a forklift with an updatable software program.SOLUTION: A microcomputer 312 has a first communication port COM1 and a second communication port COM2. A peripheral device 314 is connected to the first communication port COM1 of the microcomputer 312 via a first path P1. A communication circuit 316 is connected to the second communication port COM2 of the microcomputer 312 via a second path P2, and is connected to the first communication port COM1 of the microcomputer 312 via a third path P3. The communication circuit 316 can communicate with a removable external device. A switcher 318 switches between valid/invalid of communication via the third path P3.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a forklift.

  One of the industrial vehicles is a forklift. The forklift is capable of traveling (advancing and retreating), steering and raising and lowering the fork, and has an operation lever and a pedal (collectively referred to as operation input means) corresponding to each operation.

  The forklift includes a microcomputer that comprehensively controls traveling, steering, and raising and lowering of the fork. For example, the microcomputer has a function of monitoring operator input to the operation input means and controlling forklift travel, steering, and lift of the fork based on the input.

Japanese Patent Laid-Open No. 2007-3468

  The function of the microcomputer is described by a software program stored in a nonvolatile memory. There is a demand to update software programs to improve forklift functions and fix bugs.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and one of exemplary purposes of an embodiment thereof is to provide a forklift capable of updating a software program.

  One embodiment of the present invention relates to a forklift. The forklift has a controller that controls the operation of the forklift. The controller is connected to the microcomputer having the first communication port and the second communication port, to the device connected to the first communication port of the microcomputer via the first path, and to the second communication port of the microcomputer via the second path. A communication circuit that is connected to the first communication port of the microcomputer via the third path and that can communicate with the removable external device, and a switch that switches between valid / invalid of communication via the third path. .

  Another aspect of the present invention relates to a controller mounted on a forklift.

  Note that any combination of the above-described constituent elements and the constituent elements and expressions of the present invention replaced with each other among methods, apparatuses, systems, and the like are also effective as an aspect of the present invention.

  According to the present invention, a software program can be updated from an external device.

It is a perspective view which shows the external view of a forklift. It is a figure which shows an example of the cockpit of a forklift. It is a functional block diagram of the forklift which concerns on embodiment. It is a figure which shows the state at the time of normal operation | movement of a forklift. It is a figure which shows the state at the time of the download of the software program of a forklift. It is a block diagram of the forklift which concerns on a comparison technique. It is a block diagram which shows the forklift which concerns on one Example. It is a block diagram which shows the structure of the electric system of an electric forklift, and a mechanical system.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  In this specification, “the state in which the member A is connected to the member B” means that the member A and the member B are electrically connected to each other in addition to the case where the member A and the member B are physically directly connected. It includes cases where the connection is indirectly made through other members that do not substantially affect the general connection state, or that do not impair the functions and effects achieved by their combination.

  Similarly, “the state in which the member C is provided between the member A and the member B” refers to the case where the member A and the member C or the member B and the member C are directly connected, as well as their electric It includes cases where the connection is indirectly made through other members that do not substantially affect the general connection state, or that do not impair the functions and effects achieved by their combination.

  FIG. 1 is a perspective view showing an external view of a forklift. The forklift 600 includes a vehicle body (chassis) 602, a fork 604, a lifting body (lift) 606, a mast 608, and wheels 610 and 612. The mast 608 is provided in front of the vehicle body 602. The elevating body 606 is driven by a power source such as a hydraulic actuator (not shown in FIG. 1) and moves up and down along the mast 608. A fork 604 for supporting a load is attached to the elevating body 606.

  FIG. 2 is a diagram illustrating an example of a cockpit 700 of a forklift. The cockpit 700 includes an ignition switch 702, a steering wheel 704, a lift lever 706, an accelerator pedal 708, a brake pedal 710, a dashboard 714, and a forward / reverse lever 712.

  The ignition switch 702 is a switch for starting the forklift 600. The steering wheel 704 is an operation means for steering the forklift 600. The lift lever 706 is an operation means for moving the elevating body 606 up and down. The accelerator pedal 708 is an operating means that controls the rotation of the traveling wheels, and the travel of the forklift 600 is controlled by the user adjusting the amount of depression. When the user depresses the brake pedal 710, the brake is applied. The forward / reverse lever 712 is a lever for switching the traveling direction of the forklift 600 between forward and reverse. In addition, an inching pedal (not shown) may be provided.

  FIG. 3 is a functional block diagram of the forklift 300 according to the embodiment. The forklift 300 includes a controller 310 that controls the forklift 300 in an integrated manner. A plurality of sensors 302 are connected to the controller 310. For example, one sensor 302 monitors the current state of the forklift 300 (vehicle speed, steering angle, height of the lifting body), and another sensor 302 monitors the state of the operation input means (that is, control input from the operator).

  The controller 310 controls at least one control object 304 based on the output of the sensor 302. Examples of the control target 304 include a movable part of a forklift (that is, a traveling shaft, a steering shaft, and a cargo handling (lifting / lowering) shaft). The above is the overall configuration of the forklift 300. Next, the configuration of the controller 310 will be described.

  The controller 310 includes a microcomputer 312, a peripheral device 314, a communication circuit 316, a switch 318, and an external communication port 320. The microcomputer 312 has a first communication port COM1 and a second communication port COM2 that are serial interfaces. A software program executed by the microcomputer 312 is stored in a nonvolatile memory 313 such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) built in (or externally attached) to the microcomputer 312.

  The peripheral device 314 is connected to the first communication port COM1 of the microcomputer 312 via the first path P1, and can communicate with the microcomputer 312. The peripheral device 314 is, for example, an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated).

  The function of the peripheral device 314 is not particularly limited. For example, the peripheral device 314 has a function as an interface with a plurality of sensors 302 and a plurality of control objects 304. The peripheral device 314 converts the output of the sensor 302 into a digital signal and transmits it to the microcomputer 312.

  An external device such as a computer or another microcomputer can be connected to the external communication port 320 of the controller 310. The communication circuit 316 is an interface with an external device connected to the external communication port 320, is connected to the second communication port COM2 of the microcomputer 312 via the second path P2, and is connected to the microcomputer 312 via the third path P3. It is connected to the first communication port COM1. As an example, a data logger (not shown) is connected to the external communication port 320 in the normal operation state of the forklift 300.

  The first communication port COM1 of the microcomputer 312 supports the external space address bus output, and is used for communication with the peripheral device 314 via the first path P1 during the normal operation of the forklift 300. Further, the nonvolatile memory 313 built in the microcomputer 312 can be accessed only through the first communication port COM1.

  A switch 318 is provided in a portion connecting the first path P1 and the second path P2 on the third path P3. The switch 318 enables / disables communication via the third path P3. Control is possible.

  The above is the configuration of the forklift 300. Next, the operation will be described with reference to FIGS.

(Normal operation)
FIG. 4 is a diagram showing a state of the forklift 300 during normal operation. A data logger 306 that is a first external device is connected to the external communication port 320. The microcomputer 312 records the occurrence of various events that occur in the forklift 300. The data logger 306 stores a log data history including an event and its occurrence time (time stamp). Note that a wireless communication device may be mounted as the first external device instead of the data logger 306. In this case, the function of the data logger may be mounted on an operation management device outside the forklift 300.

  During normal operation, the switch 318 is off (disabled), and communication via the third path P3 is disabled. The microcomputer 312 transmits / receives data necessary for controlling the forklift 300 to / from the peripheral device 314 by bus communication using the first communication port COM1 and the first path P1.

  The microcomputer 312 and the data logger 306 can communicate with each other by serial communication via the second communication port COM2 and the second path P2, and serial communication between the data logger 306 and the communication circuit 316. Receive event information from and record it as log data.

(When downloading software programs)
FIG. 5 is a diagram showing a state of the forklift 300 when the software program is downloaded. When downloading the software program, a computer 308 as a second external device is connected instead of the data logger 306. At this time, the switch 318 is turned on (enabled), and communication via the third path P3 is enabled.

  In this state, the microcomputer 312 can communicate between the first communication port COM1 and the computer 308 via the third path P3 and the communication circuit 316. From the computer 308, software is transferred to the internal nonvolatile memory 313. The program can be downloaded.

  The above is the operation of the forklift 300. The advantages of the forklift 300 will become clear by comparison with the following comparative technique.

  FIG. 6 is a block diagram of a forklift 300R according to the comparative technique. The controller 310R includes a microcomputer 312, a peripheral device 314, and a communication circuit 316, and the switch 318 is omitted from FIG.

The functions of the peripheral device 314, the microcomputer 312 and the communication circuit 316 are the same as in the embodiment. The architecture (function or restriction) of each block is organized as follows.
The downloading of the software program to the microcomputer 312 is supported only for the first communication port COM1.
The first communication port COM1 is used for both (i) serial communication with the communication circuit 316 and (ii) external space address bus output (communication with the peripheral device 314). That is, data supply to the peripheral device 314 is supported only via the first communication port COM1.
The second communication port COM2 normally outputs data.
The function assignment (serial communication / external space address bus output) of the first communication port COM1 is set when the microcomputer 312 starts up.

  During normal operation, data to be supplied from the second communication port COM2 to the data logger 306 is also supplied to the peripheral device 314 via the fourth path P4 indicated by a one-dot chain line. That is, communication at the external space address bus output via the first path P1 and serial communication via the second path P2 collide, and correct data cannot be supplied to the peripheral device 314.

  In order to solve the problem in the comparison technique, an approach may be adopted in which a microcomputer for which a serial communication port and an external space address bus output port are independently provided is employed. However, since such a microcomputer is large and has high specifications, it causes problems such as an increase in mounting area and an increase in cost.

  Another approach to solving the problems in the comparison technique is to make the software program download independent of the external data logger path. However, in this case, since one more connector and serial communication circuit are required, an increase in mounting area and an increase in cost are inevitable.

  In turn, the advantages of the forklift 300 according to the embodiment will be described. The forklift 300 is provided with a switch 318 so that communication via the third path P3 can be disabled during normal operation. As a result, it is possible to prevent a collision between the external space address bus output via the first path P1 and the serial communication via the second path P2. As will be described later, the switch 318 can be constituted by a three-state buffer or a switch, so that an increase in mounting area and cost is slight.

Next, a more detailed example of the forklift 300 will be described. FIG. 7 is a block diagram illustrating a forklift 300A according to an embodiment. The controller 310 </ b> A includes a three-state buffer 330 as the switch 318. Specifically, the input of the three-state buffer 330 is connected to the second path P2, and the output is connected to the first path P1. The microcomputer 312 is provided with a mode switching pin MODE, and the function of the first communication port COM1 (serial communication / external space address bus output) can be set according to the state of the mode switching pin MODE. The enable / disable of the three-state buffer 330 may be linked to the mode of the microcomputer 312. Therefore, the mode switching signal (or its inverted signal) S _{MODE applied to the} mode switching pin MODE is connected to the enable terminal of the three-state buffer 330. Can be supplied. The mode switching signal S _MODE is automatically generated according to the connection status of the external device. The mode switching signal S _MODE may be generated by an external device. Alternatively, a circuit for monitoring the state of the external communication port 320 may be added, and this circuit may be generated based on the type of external device connected to the external communication port 320.

  FIG. 8 is a block diagram showing a configuration of an electric system and a mechanical system of the electric forklift. The controller 110 is a processor for controlling the forklift 600 as a whole, and corresponds to the controller 310 described above. The battery 100 is a main power source of the forklift 600, and the voltage of the battery 100 is supplied to various blocks of the forklift 600.

(Running)
The controller 110 receives a signal for instructing forward / reverse from the forward / reverse lever 712 and a signal indicating a travel operation amount corresponding to the depression amount from the accelerator pedal 708, and a control command value (both travel operation amount) corresponding thereto. S1) is output to the first power converter 200. The first power conversion device 200 controls the power supplied to the travel motor M1 according to the control command value S1. The control command value S1 has a correlation with a speed command value that indicates the target rotational speed of the traveling motor M1. The front wheels 610 that are drive wheels are connected to the drive shaft 114. The gear box 112 and the drive shaft 114 transmit power from the travel motor M1 to the front wheels 610. A signal from the forward / reverse lever 712 to instruct forward / reverse and a signal indicating the amount of travel operation are detected by the sensor 302 in FIG. Moreover, the 1st power converter device 200 is corresponded to the control object 304 of FIG.

(Handling)
The vertical movement of the elevating body 606 is controlled by the inclination of the lift lever 706. The tilt of the lift lever 706 is detected by the sensor 302 in FIG. The controller 110 outputs a signal indicating the cargo handling operation amount S <b> 2 corresponding to the inclination to the second power conversion device 102. The second power converter 102 supplies power corresponding to the cargo handling operation amount S2 to the cargo handling motor M2, and controls its rotation. The elevating body 606 is connected to the hydraulic actuator 116. The hydraulic actuator 116 converts the rotary motion generated by the cargo handling motor M2 into a linear motion and controls the lifting body 606. The second power converter 102 corresponds to the control target 304 in FIG.

(steering)
The steering wheel 704 is connected to the steering linkage via the steering shaft 120. The forklift has a power steering function. The encoder 122 corresponding to the sensor 302 in FIG. 3 detects the rotation angle of the steering wheel 704 and outputs a signal indicating the rotation angle to the controller 110. The controller 110 outputs a control signal S3 corresponding to the rotation angle to the third power conversion device 104. The third power conversion device 104 supplies power corresponding to the control signal S3 to the steering motor M3, and controls the number of rotations thereof. The rotational motion of the steering motor M3 is transmitted to the hydraulic actuator 118, and the steering of the rear wheel 612 is controlled. The third power converter 104 also corresponds to the control target 304 in FIG.

  In the above, this invention was demonstrated based on the Example. It will be understood by those skilled in the art that the present invention is not limited to the above-described embodiment, and various design changes are possible, various modifications are possible, and such modifications are within the scope of the present invention. By the way. Hereinafter, such modifications will be described.

(Modification 1)
As the switch 318, a semiconductor switch may be used instead of the three-state buffer 330. Even in this case, the semiconductor switch may be turned on / off by a signal common to the mode switching pin MODE of the microcomputer 312.

(Modification 2)
If the GPIO (General Purpose Input / Output) pin of the microcomputer 312 is left, the microcomputer 312 may generate a control signal for the switch 318.

(Modification 3)
The mode switching signal S _MODE may be generated according to an operation input by the operator. That is, a mechanical or software switch for switching the mode may be prepared, and the mode may be selected based on an operation input by the operator. Alternatively, a mechanical switch may be used as the three-state buffer 330 so that the operator can manually turn it on and off.

(Modification 4)
Although the electric forklift has been described as an example in the embodiment, the application of the present invention is not limited thereto, and can be applied to an engine-type forklift.

600 Forklift 602 Car body 604 Fork 606 Lifting body 608 Mast 610 Front wheel 612 Rear wheel 100 Battery 200 First power converter 102 Second power converter 104 Third power converter 110 ECU
DESCRIPTION OF SYMBOLS 112 Gear box 114 Drive shaft 116,118 Hydraulic actuator 120 Steering shaft 122 Encoder M1 Traveling motor M2 Carrying motor M3 Steering motor 700 Pilot's seat 702 Ignition switch 704 Steering wheel 706 Lift lever 708 Accelerator pedal 710 Brake pedal 712 Forward / reverse lever 714 Dashboard DESCRIPTION OF SYMBOLS 300 Forklift 302 Sensor 304 Control object 306 Data logger 308 Computer 310 Controller 312 Microcomputer 313 Non-volatile memory 314 Peripheral device 316 Communication circuit 318 Switcher 320 External communication port 330 Three-state buffer P1 1st path P2 2nd path P3 3rd path COM1 1st communication port COM2 2nd Communication port

Claims (4)

A forklift having a controller for controlling the operation of the forklift,
The controller is
A microcomputer having a first communication port and a second communication port;
A device connected to the first communication port of the microcomputer via a first path;
A communication circuit connected to the second communication port of the microcomputer via a second path, connected to the first communication port of the microcomputer via a third path, and capable of communicating with a removable external device;
A switch for switching between valid / invalid of communication via the third path;
A forklift characterized by comprising:   The forklift according to claim 1, wherein the switch operates according to a mode switching signal generated according to a connection status of the external device.   The forklift according to claim 1, wherein the switch is a three-state buffer. A controller mounted on a forklift,
A microcomputer having a first communication port and a second communication port;
A device connected to the first communication port of the microcomputer via a first path;
A communication circuit connected to the second communication port of the microcomputer via a second path, connected to the first communication port of the microcomputer via a third path, and capable of communicating with a removable external device;
A switch for switching between valid / invalid of communication via the third path;
A controller comprising:

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