Sensor targets ESP apps in compact-class vehicles
LWS6 steering-angle sensor
Bosch has extended its steering-angle sensor offering to include a cost-effective model that is said to be especially suitable for ESP applications in vehicles of compact class and below.
The signals from the LWS6 can also be used for systems such as electro-hydraulic power steering or ACC adaptive cruise control.
The LWS6 measures relatively over an unlimited measuring range and its typical steering-angle signal resolution is 1.5deg.
It uses Hall effect technology, for which a multi-pole magnet is fixed to the steering column.
Hall elements detect changes in the sensor's magnetic field without contacts and without gear wheels.
As two or more Hall elements are used, any rotary motion generates square-wave signals, which show a certain phase shift relative to each other.
These square-wave signals are transmitted directly to the control unit, ruling out any need for evaluation logic in the LWS6.
Processing of the sensor signals is carried out by the system control unit, which calculates the position, rotation direction and rotation speed of the steering wheel.
The control unit also validates the sensor output signals and detects short circuits, for example.
Due to the incremental measuring principle of the LWS6, it no longer has to be calibrated by the car manufacturer.
As there is no mechanical link between the Hall measuring elements and the magnetic hub, the sensor is wear-free.
The magnetic measuring principle makes the LWS6 resistant to contaminants, such as dust.
As with the LWS5, the LWS6 does not require standby current when the vehicle is parked.
Customer-specific designs offer extensive adaptation options for a variable steering-column installation or integration into the switch unit.
The Bosch sensor has been developed in accordance with current environmental requirements and is made from lead-free components.
The Bosch SMI540 is a micro-mechanical inertial measurement unit for vehicle dynamics control in low-cost SOIC16W housing.
Sherborne Sensors has introduced the T233/T235 series of dual-axis servo inclinometers for military and industrial applications, from structural alignment to gun-fire control.
Gravity-referenced inertial inclinometers are in effect low-frequency response accelerometers and derive their angular information from the acceleration due to gravity, the output being proportional to the normal component of the gravity vector. It is perhaps surprising that some users do not appreciate that the inclinometer output is proportional to the sine of the angle and not the absolute angle in degrees.
A new tip-tilt mechanism based on low-voltage piezoelectric actuators has been designed by Cedrat Technologies to answer the high level of stability required for the Earthcare satellite. The Beam Steering Assembly aims to deviate a pulsed high-energy UV laser beam to compensate for misalignment between the emission and reception paths of ATLID with a very high stability and resolution.
Typical sensors that have an intrinsically linear output include pressure transducers and loadcells. However, many commonly used sensors exhibit very non-linear performance, leading to the conclusion that they are also not accurate. In truth, as this article from Sherborne Sensors explains, a sensor can be highly accurate but also have a totally non-linear output function, and sensors with very linear outputs can be highly inaccurate.