Off-road vehicles are designed to perform the most difficult tasks in often in the most extreme outdoor conditions. In industries like construction, forestry and agriculture, vehicles often have to navigate on uneven surfaces and slippery terrain whilst lifting and manoeuvring heavy and uneven loads. This can present difficult challenges for the drivers of these vehicles: for many vehicle operators, the chances of tipping or rolling the vehicle over are high, so obviously safety is a paramount concern. However, electronic sensing technology is now available which makes the vehicle driver’s job easier and safer. As these electronic sensors can detect the vehicle’s operating condition and alignment, the safety of the operator is greatly increased.
Tilt Sensors Monitor the Safe Horizontal Alignment of Vehicles
Off-road vehicles often have to work in extreme conditions, where rugged terrain and heavy moving machine parts can quickly shift the balance of a vehicle. A shift in the dynamics of the vehicle or an uneven transfer of weight or dangerous alignment can cause hazardous conditions for the vehicle operator. Electronic sensors can help operators to monitor the horizontal alignment of vehicles. Tilt sensors can precisely detect even the slightest angle variation. Tilt sensors can give the driver accurate information about the exact road-grade angle, the boom angle, the platform angle and the crane-level angle. Armed with this important information, an operator can then take action to avoid a potentially disastrous situation.
Tilt sensors, however, need to sturdy and resilient. They have to be able to withstand the extreme shock, vibration, and all the harsh elements associated with outdoor use. Moreover they also have to be able to cope with direct exposure to chemicals, dirt, moisture, sunlight, and electrical interference. Therefore tilt sensors have been designed so that they are capable of resisting these elements and are able to perform in extreme environments. They are able to do so because of certain special design features like:
- Compact housings – rated for IP67 protection – which encase and protect the electronics from chemicals and liquid ingress,
- UV-resistant plastic and metal housings which prevent damage from exposure to sunlight,
- Noise-immune technology which enables the sensors to ignore conducted and radiated electrical noise.
- Outputs protected from short-circuits and overloads which eliminate damage during installation,
- Highly flexible cables, which are armoured to resist chemicals and perform at temperatures as low as –40 °F.
There are two very different, yet highly effective sensing technologies that can be applied to verify the horizontal alignment of off-road vehicles: electrolytic tilt sensing and micro electromechanical sensing. (MEMS)
Electrolytic tilt sensing
Electrolytic tilt sensing technology can measure the tilting of a reference plane in two axes, by measuring the tilt angle with reference to the earth’s ground plane, using an accelerometer. At the centre of the sensors core are measuring cells surrounded by fluid or liquid. These measuring cells monitor ant change in the liquid’s conductivity to detect angle variations and deviations.
MEMS sensing technology
The second technology is micro electromechanical sensing (MEMS). When a vehicle lifts or tilts, the movement is transferred to the beams of the sensor that deflect to take the inertial force of the mass. The change in capacitance is proportional to the tilt of the sensor, which is ultimately then converted to a change of voltage and transferred as an analogue value to the driver of the vehicle. The use of MEMS sensors incorporating this technology are better suited to applications where a single-axis wide tilt angle (±90°) and lower precision (±1°) are needed.