Every jobsite has an abundance of attention-grabbing distractions. A construction vehicle driver has to pay heed to a swirl of stimuli. Controlling the equipment has its own challenges. Then there are other vehicles that cruise the site, terrain, time crunches, pedestrians, pleasant/unpleasant weather -- not to mention whatever was on that operator''s mind at the start of the day, and fatigue as the shift progresses.
But losing focus while operating heavy equipment is risky business. The cost of a split second of inattention can be crushed body parts or worse.
Avoiding all missteps is humanly impossible, so Rayco Manufacturing Inc is one of several equipment builders that have turned to microprocessor technology to offer a machine that can think ahead of the driver
Rayco teamed up with control systems developer HED, Inc, to insure that their C85D Mini Crawler will not start up unless the operator performs a series of steps. The routine protects the machine from getting underway if the operator is out of place.
The 8,200 lb Mini Crawler is Rayco''s latest vehicle for construction in tight places. Despite its compact size, this dozer delivers heavy-duty performance with a blade featuring versatile six-way articulation. At a track base and width each measuring 69 in., the Mini Crawler is just large enough to contain its 83 HP diesel engine. Yet nestled within the vehicle are electronics that enable sophisticated functions.
HED offered Rayco the CL-401, a controller that processes information and sends out commands to a number of components within the dozer. The solid state microprocessor-based CL-401 pulls in inputs from the safety belt, seat switch, safety arm, and the ignition switch. Plus, to care for the vehicle''s welfare, the board monitors engine functions such as oil pressure, oil temperature, air filters; plus insuring hydraulic fluid level.
This single board controller (SBC) is part of HED''s growing CANLink® family of control components, offering mobile construction product designers a number of ways to electronically control functions for any size or type of vehicle.
Based on the information directed to the CL-401, the resident software program within the controller, and operator input, the CL-401 manages the system''s solenoids and a bank of indicator LEDs housed in a box over the driver''s head.
The system is on guard to look after both man and machine. If the driver grinds the starter for a specified time period, the CL-401 will turn off the starter solenoid to prevent burnout. Should the ignition key be turned without starting the engine, the controller will prevent battery drainage. In the meantime, the controller will activate lights in the cabin to alert the driver to the interruption in dozer operation.
The controller contributes to the driver''s well being by blocking off the signal to the starter unless all safety functions are in place. The machine functions are all pilot operated hydraulics, with pilot pressure bypassed by a valve. The CL-401 controls that valve. Should the operator decide to get more comfortable by unhooking the seat belt, the system reacts by signaling the valve to disable the hydraulic system. The engine will continue to run until the driver either buckles up or shuts off the ignition. The driver will find that disengaging any of the safety interlocks renders the machine inoperable. Tracks and the blade, in particular, come to a halt.
The CL-401 module has 18 inputs and 16 outputs that can interface with many types of signals and sensors. Early system configurations did not use all of the inputs and outputs. Now, Rayco has found jobs for all of the hardware interfaces.
The module represents advancement in system design for Rayco. According to Bruce Chapman, manager of product engineering, "We were looking for technology that would handle some logic functions we previously handled with relays and fuses."
The CL-401 is an ideal component for tough construction. Housed in waterproof NEMA-4 case, the solid-state circuitry is immune to interference from harsh weather, extreme temperatures and humidity, equipment vibration, and potentially conflicting signals (EMI/RFI) from the host of radio devices and other transmitting devices present on a job site. All connections to the module are jacketed to prevent problems.
The CL-401 reliability rewards the driver for performing all steps correctly. In a vehicle with standard electronic components, imagine the frustration flaring up if all safety functions are properly performed and a malfunctioning system prevents vehicle operation. The microprocessor system virtually guarantees the vehicle will start up if the driver complies with all safety requirements.
HED can also provide a diagnostic program for fast and easy diagnosis. Hooking up a laptop with an RS232/CAN converter to the CL-401 field technicians can troubleshoot the electronics on the vehicle, checking for open circuits, shorts, or problematic inputs.
With the inclusion of a small component such as the CL-401, even compact vehicles such as the Rayco Mini-Crawler can offer the sophisticated functions of much larger equipment.