Wireless wheel alignment provides speed and convenience for automobile technicians

Citation

(2003), "Wireless wheel alignment provides speed and convenience for automobile technicians", Sensor Review, Vol. 23 No. 2. https://doi.org/10.1108/sr.2003.08723baf.002

Wireless wheel alignment provides speed and convenience for automobile technicians

Wireless wheel alignment provides speed and convenience for automobile technicians

Keywords: Wireless, Automotive

A leading supplier of high-performance, cost-effective 2.4 GHz spread spectrum wireless modules AeroComm has developed a wireless system for use in wheel alignment applications that removes cumbersome umbilical cables from the workplace whilst simplifying and speeding up the process (Plate 1).

AeroComm transceivers are integrated into each of four wheel heads, and another server transceiver is integrated into the central control console to enable wireless communication to each wheel. However, before RF could replace wires, several capabilities had to be integrated into a small, low power, cost effective transceiver.

Plate 1 The wireless system from AeroComm removes cumbersome umbilical cables from the workplace

A specific attribute required for wheel alignment applications meant that the system had to be globally acceptable, including the use of an unlicensed radio frequency, as manufacturers of wheel alignment systems are typically large corporations with global marketing strategies. This necessitates a transceiver with virtual worldwide acceptance.

Also a requirement was for a low latency, wire-like communication performance. Wheel alignment systems are comprised of a control loop. The mechanic makes an adjustment; the sensor reads that adjustment and sends the data to the control console. The system must also be fast enough to enable frequent updates from four different wheels.

In operation, the system communicates sensor data read by each wheel head to the central console, where the information is displayed on the screen. The central console may also provide the mechanic with voice instructions to adjust wheel alignment.

Typically the system uses an integral antenna as transmission ranges are short, and large external antennas are not necessary. The server transceiver within the central console may connect to custom base station electronics, or optionally it may connect to a RS232 port on a "PC based" central console.

The AeroComm receivers operate using client/server architecture where the server radio controls the network. The server informs the client transceivers when and where to hop. This pseudorandom hop table is identified by a "channel" number. To co-locate multiple wheel alignment systems, they are simply set to different channels. The system then hops to different frequencies, avoiding interference and enabling multiple independent networks. This flexibility also enables other equipments such as brake repair and tire changers to incorporate wireless communication without interference.

The use of AeroComm's wireless solution for wheel alignment offers several advantages for OEMs. Frequency hopping, spread spectrum (FHSS) techniques employed ensure excellent interference rejection, overcome multipath problems, and allow variable power outputs.

Integral antenna versions reduce cost and eliminate external antennas that might get damaged in a workshop environment. The transmitting format; point to multipoint communication, is supported with AeroComm standard configurations and it supports addressed or broadcast packets. The OEM is able to use the address embedded in the RF-module, alternatively their own addressing scheme.

The system architecture supports both polled or random communication, and ACK and retry protocol are embedded for data integrity. The fast RF rates used support frequent sensor updates. Versatility is enhanced by the use of multiple channels that allow larger workshops to operate more than one wheel alignment system at the same time.

For further information, please contact: John Clark, BFI OPTiLAS Ltd, Mill Square, Wolverton Mill South, Milton Keynes, MK12 5ZY, UK. Tel: +44 1908 326342; Fax: +44 1908 221110; E-mail: john.clark@bfioptilasavnet.com.