US 5,687,081 AGranted

Lift truck control system

AssigneeCrown Equipment Corporation

InventorsTimothy A. Wellman, John C. Wilkinson, Jr., Nicholas D. Thobe, Ned E. Dammeyer, Mark E. Schumacher

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Abstract

A lift truck control system which utilizes a distributed control network including at least a display module, a distribution module, a traction module, a brake module and a steering module. The display and steering modules each are configurable by software which controls the module and the various drivers in each module. In the preferred embodiment, the display module includes flash memory which stores application software and can be rewritten so that the performance characteristics of the modules are software configurable. The display module is connectable to a programmable cartridge which includes nonvolatile flash memory that carries application software for the display and steering modules. When connected, the cartridge downloads the particular application software which is written over the stored software in flash memory for the display and steering modules. The programmable cartridge also can be used to store and download boot software to the display and steering modules, so that the boot procedure performed by the display and steering modules is also software configurable. The system accepts modules which can be installed in a variety of different lift truck vehicles with minimal physical changes; the performance of the modules is configured by the application software written into the flash memory of the module.

Claims24

Dependent claims

A control system for a lift truck comprising:

a plurality of operation modules residing on said lift truck for controlling operation of a corresponding plurality of lift truck components each of said plurality of operation modules including,
(a) a random access memory for storing said corresponding application program, and
(b) a processing circuit for executing said corresponding application program stored in said random access memory and for controlling operation of said corresponding lift truck component according to said execution of said corresponding application program;
a memory module residing on said lift truck, including a non-volatile memory for storing a plurality of application programs for driving said plurality of operation modules, and including means for connection to an external memory source containing said plurality of application programs;
and
a network for interconnecting said memory module and said plurality of operation modules and for transmitting said plurality of application programs from said non-volatile memory of said memory module to said random access memories of said plurality of operation modules, whereby functioning of said operation modules is varied by replacement of a corresponding one of said application programs in said non-volatile memory of said memory module;
said memory module transmits said corresponding application program from said non-volatile memory of said memory module to said random access memories of said plurality of operation modules during a boot procedure, whereby the operation of each of said plurality of operation modules can be varied by downloading said plurality of application programs from said external memory source to said non-volatile memory of said memory module.

4 more elements

For use in a lift truck of a type including a plurality of operation modules and a memory module residing on said lift truck, each of said operating modules having first nonvolatile memory for storing identification data identifying said operation module and for storing a resident boot program, and each of said operating modules also having a random access memory, said memory module including a non-volatile memory for storing a plurality of operation application programs, each of said application programs having instructions for controlling a corresponding one of said plurality of operating modules, said plurality of operation modules and said memory module being interconnected by a distributed network, a method of identifying and configuring said plurality of operation modules comprising the steps of:

initiating said resident boot program;
verifying that said identification data is valid and, if said identification data is valid, continuing with said method;
and
loading each of said application programs from said non-volatile memory of said memory module to a random access memory associated with a corresponding one of said operation modules such that said operation modules are configured according to said instructions of said corresponding application programs.

1 more element

Dependencies are inferred from the claim text.