What's New at Efector
Tilt sensors monitor horizontal alignment
of vehicles
Off road vehicles are designed to perform arduous tasks
in extreme conditions. Moving and lifting heavy loads on
uneven ground is typical of vehicles used in construction,
forestry and agriculture.
Rugged terrain and moving machine parts
can quickly shift the balance of a vehicle. A dangerous
alignment can cause hazardous conditions for a vehicle operator.
To assist operators in monitoring the horizontal
alignment of vehicles, ifm efector offers a family of tilt
sensors. By detecting slight variations in tilt, these sensors
can report the exact road-grade angle, boom angle, platform
position and crane-level angle. Upon receiving these signals,
an operator can take action to avoid an unsafe situation.
Depending on the type of tilt sensor, ifm
efector applies two very different sensing technologies
to verify horizontal alignment.
Electrolytic tilt sensing
The first technology is referred to as electrolytic tilt
sensing. Sensors filled with electrically conductive liquid
are fitted with two internal measuring cells. By applying
an alternating voltage between the cells' electrodes, current
flows through the liquid and generates an electrical field.
If the sensor tilts, the fluid surface remains level, so
the electrical field changes – as well as the fluid's level-dependent
resistance. The measuring cells monitor any change in the
liquid's conductivity and thus detect angle variations of
the X and Y axes with precision. This technology is used
in ifm efector's dual-axis CANOpen sensors. These devices
are appropriate for platform leveling (narrow tilt angle
±15°) or where high precision (0.025°) and a flexible network
connection are advantageous.
MEMS sensing technology
The second technology is called micro electromechanical
sensing (MEMS). A silicon mass is suspended in the sensor
body by two resilient beams between two stationary capacitor
plates. When the body tilts, the movement is transferred
to the beams. The beams deflect to take the inertial forces
of the mass. The deflection changes the relative position
of the mass between two plates. Because each of the above
plates is part of two separate capacitors, the deflection
creates a reciprocal change in capacitance in each of the
two. Any change in capacitance is proportional to the tilt
of the sensor, which then is converted to a change of voltage
and transferred as an analog value to the vehicle controller.
These sensors are extremely robust, inexpensive, and offer
improved stability over competing technologies. They are
better suited to applications where a single-axis wide tilt
angle (±90°) and lower precision (±1°) are needed.
Tilt sensors withstand harsh environmental
conditions
To perform in mobile equipment, any tilt sensor must withstand
the extreme shock, vibration, and harsh elements associated
with outdoor use. Direct exposure to chemicals, dirt, moisture,
sunlight, and electrical interference is common. Design
features that enable these products to survive in adverse
environments include:
- Compact housings – rated for IP67 protection
– that encase and protect the electronics from chemicals
and liquid ingress.
- UV-resistant plastic or metal materials
in the housings to prevent damage from exposure to sunlight.
- Noise-immune technology lets the sensors
ignore conducted and radiated electrical noise.
- Short-circuit, overload and reverse polarity
protected outputs eliminate damage during the installation.
- Highly flexible cable, jacketed to resist
chemicals and perform at temperatures as low as –40F.
For more information on this product or
any other Efector products please visit our service
area to find a representative near you.
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