Inductive high speed rotor position sensor (SPINpad sensor)
The demanding requirements of hybrid or electric vehicle applications require sensors that match the latest developments of electronic systems including response time, accuracy and robustness against temperature and vibration effects. The functionality and efficiency of the engine electronics depend directly on the reliability of sensors from which physical quantities such as speed or position convert into electrical signals and are transmitted to the control unit.
TT Electronics´ new inductive high speed rotation and position technology (SPINpad) offers special features to support these innovative systems, and surpasses significantly the signal detection accuracy of classic commercially available systems.
The SPINpad technology was developed in accordance with ISO 26262 and supports the ASIL B Level in the application. It enables the accurate detection of speed and rotary position, especially for sensors in the engine and vehicle mount portion of the drive train.
The basic structure of the SPINpad technology is based on the proprietary Autopad® technology, an inductive, non-contact position system, which is already used by the millions in the field. For use in the SPINpad sensor, the coil structure with a transmitter coil and two receiver coils have been adapted and optimised for precision.
The new SPINpad technology uses a two-channel system by default. The information from the second channel may optionally be used, according to customer demands and the target application, to increase accuracy or for higher security requirements (at least ASIL B). While conventional resolving technology is reaching the limits of its accuracy, SPINpad technology is just beginning.
For additional demands of precise linear positioning with a small footprint, our proprietary SIMPSpad technology is ideal, with the ability to sense position even through non-ferromagnetic metals.
- Absolute angle calculated immediately after power on
- Precise position signal over 360° using two channels
- B-field immunity
- Vernier calculation
- Redundant system for mission critical systems
- Combined position and speed signal
- Small design
- Economical construction through simple designs
- Development according to ISO 26262 - FUSI: ASIL (B)
- Interface for speed: sine, cosine, pulses
- Interface for absolute angle: SENT according Revision 4; PSI5 (with 20Bit)
The SPINpad technology offers a wide field of applications in engine and vehicle mounting area or drive train of hybrid or electric vehicles, from cars and trucks to off road vehicles. Application is possible on all rotating shafts (crankshaft, camshaft, wheels and gears). The new technology can replace existing systems where higher speed and accuracy are required. In addition, as a combined system the sensor can meet new system requirements of saving weight, space and costs.
SPINpad technology can use a second independent measuring channel in the same space. Using the Vernier principle, the data can be combined to achieve far greater accuracy. In direct comparison to current systems that are at the limits of their accuracy, SPINpad technology is in its infancy and has great potential for the next generation of sensors. Using a sample of the first prototypes and angles over a full rotation of 360°, a maximum error of ± 0.06% was measured. Using the new SPINpad technology in position sensors, rotational speeds of up to 30,000 rev / min can be measured at temperatures from -40°C to + 150°C .
Internal combustion engines can incorporate a sensor to generate analog outputs (sine + cosine) in addition to the absolute angle (analog voltage or digital protocol PSI5; generated Sent) and pulses. The pulse output is freely programmable and can be used as a classic camshaft or crankshaft sensor.
The opportunities for camshaft adjustment are examples of how AB Elektronik is providing sensor systems that enhance conservation of our natural resources and further reduce CO2 emissions.
It is even possible to use the same sensor technology for camshaft and crankshaft. After mechanical adjustment, the pulse output can be programmed accordingly.
SPINpad technology provides a two-channel design as standard. This allows production of a combined sensor - for instance for the simultaneous determination of angular position and speed. Using the two different carrier frequencies, two independent determinations of angular position can be performed in parallel and output as PSI5 or SENT. Thus two functions can be achieved in one sensor, saving both cost and space. Such a combined sensor can be implemented as a level sensor for example.
In addition to the possible applications mentioned, other combinations of characteristics can be implemented according to customer requirements.