PRODUCTS & SERVICES
HYDRAFORCE
Hybrid solutions for autosteering
THANKS TO GPS-GUIDED AUTOSTEERING SYSTEMS, OPERATORS CAN BENEFIT
FROM REDUCED FATIGUE AND ENHANCED WORKING PRECISION
68
iVTInternational.com June 2019
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The market for global navigational satellite
systems has doubled during the past five years.
The technologies that we depend on for agriculture,
construction, mining and other industries are becoming
smarter and more autonomous than ever before.
In precision farming, yield mapping ensures that the
exact amount of fertilizer is applied to the correct area of
the field, and combine harvesters can track an optimized
path through the crop. In mining, ore trucks can
navigate the circuit from pit to pile and back again, with
greater efficiency. In construction, graders and
compactors can complete their tasks in fewer passes
than previously and compaction accuracy is improved.
While autosteering systems have their benefits, they
require a human operator to supervise and to take over
the vehicle instantly, if or when necessary, for safety
reasons. Humans are also required to carry out routine
tasks that the guidance system may be unable to
perform, such as navigating between fields or jobsites.
Hybrid systems use a steering orbital in parallel with
the autosteering valve. The circuit design gives instant
priority to manual steering.
Steer-by-wire systems enable operator control via
an electronic input device, such as a joystick, knob or
electronic steering wheel. Steer-by-wire allows
enhanced controllability with features such as variable
ratio steering that adjusts to the speed of the vehicle.
Smart electronic controls may also enhance safety by
predicting potential stability issues and damping erratic
or unsafe operator inputs.
Five-way proportional valve
At the heart of these systems are proportional hydraulic
controls that are able to operate at the highest speed
and with the highest precision. HydraForce’s new
fast-acting five-way, three-position proportional valve.
The SP10-57F is a minimum overlap, proportional
directional control valve with excellent response time.
Perfect for closed-loop autosteering control systems,
the valve works well to dynamically control the position
of steering cylinders. The satellite navigation system
provides real-time feedback to close the control loop,
continuously making many minor adjustments each
second. With a fast response of 31 ms, the SP10-57F
is typically able to respond up to 25 Hz.
The five-way proportional design of the SP10-57F
includes an integral load signal at port one. The pilot
ABOVE: The SP10-57F is ideal for use in closed-loop
autosteering control systems
signal can communicate load pressure, or even flow
demand, to a logic valve for priority flow-sharing or
load-sensing systems. A benefit of using a five-way valve
is that the bidirectional load signal does not require
logic to determine the direction of operation. This is a
distinct advantage over CETOP/D03 valves, which are
dependent on a four-port (P, T, A, B) interface pattern.
Complete vehicle control
HydraForce offers additional components to complete
the autoguidance system. To switch the system between
auto and manual steering modes, a four-way,
two-position, selector valve can be used. This can be
solenoid-operated to toggle the system electronically,
or pilot-operated to achieve a hydraulic interlock.
Hall-effect position sensors are available for either
type of selector. Priority flow dividers can peel off the
needed pump flow for steering, thereby diverting the
balance to other functions. And a selection of logic
valves is available to perform functions like pump
unloading, or pressure-compensation. Load-holding
valves can also be integrated if necessary to hold the
steering cylinders in a static position. The package can
be designed to mount directly onto the steering orbital,
or it can be remotely mounted elsewhere on the vehicle.
A flexible array of CANopen/SAE J1939 networked
electronic control units (ECUs) and valve drivers provide
smart electronic controls. Gate and Globe offers a
complete IoT (Internet of Things) platform to connect
the vehicle, or a fleet of vehicles, to a global service
and telematics network.
Author: Ben Dupre, senior technical writer, HydraForce
Gate and Globe
telematics solutions
ECU with ISObus,
CANopen, J1939
SP10-57F
Fast-acting
directional
control valve
Auto-steering manifold
/iVTInternational.com
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