March/April 2005

Trailers and other unpowered assets are harder to track than vehicles, but recent developments have brought prices down to affordable levels. Sharon Clancy reports

Tracking trailers for security purposes (for instance, to monitor loads in transit) is relatively simple - with one proviso. In traditional systems, the trailer has to be hooked up to a tractor unit, and remain attached. Many systems claiming to offer trailer tracking do so only via the tractor unit. However, if the trailer is hitched to a hired tractor unit that has no tracking system fitted, or is stolen or simply parked up by itself in a depot, then monitoring its whereabouts becomes more difficult and expensive.

Yet there are good reasons to do it. Trailer location is as much about improving fleet utilisation and maintenance scheduling as it is about load tracking. Doing the monitoring automatically is clearly more efficient than having someone walk round the depot taking a note of all the trailer numbers. But the cost of automated tracking has been the big deterrent, as has the technical challenge of powering location devices on trailers, which usually have no on-board power source.

Now a new generation of tracking systems is emerging, making the concept more affordable, and at the same time overcoming some of those technical problems. The cost of combined GPS/GSM tracking units has fallen rapidly, and today can be as little as £300 (plus the communications cost). And leasing options can take the sting out of the price anyway.

 

The chief technical problem with trailer location has been how to maintain an adequate power supply to an on-board telematics unit. Rechargeable batteries have been the favoured solution, recharged with a trickle feed from the tractor unit whenever the trailer is hitched up. Solar panels are an alternative for units left parked up.

A new type of hybrid battery is the latest promising solution to the power problem, and is being used by Axscend and TISS Trailer Security. The battery pack is not rechargeable, but it is claimed to have a seven-year life if it is providing two location reports a day. The hybrid lithium thionyl chloride batteries deliver their full capacity under higher loads for short periods, and are recharged during the low-power state. The self-discharge rate is one to two per cent a year, and the batteries will operate in temperatures from minus 40 deg C to plus 85 deg C.

TISS's latest Internet-based trailer tracking system costs only 10p a day per vehicle. The unit is attached to the roof or inside a trailer via an adhesive backing, and there is no wiring. The system provides the vehicle's position every day - even if the vehicle is inside a workshop or under cover. Locations are sent via GSM phone network to TISS's server.

Alex McCracken, commercial director, for TISS says: "Companies with large fleets don't need expensive, complex tracking for their trailers - they just want to know where trailers are every now and again, to make sure they have not moved. The unit is also transferable, so when working with leased trailers, users can transfer it to replacement trailer at the end of a lease period. It is a low-cost system that transport managers can use to 'ping' their vehicles every day, week or month according to their needs."Ê Ê

Axscend uses satellite communications for position reporting, reflecting its products' American heritage. The company, which is a subsidiary of UK-based communications network specialist BCM Transport, says data communications by satellite are not as expensive as people think.

"Many satellite-based asset management systems use duplex satellite architectures to provide simultaneous two-way communications," explains Stuart Hobbs, sales and marketing executive for Axscend. "Asset tracking doesn't require the complication of continually providing a 'receive' capability, or demand the broad bandwidth needed for voice communications."

The AXTracker tracking device combines a GPS engine and Globalstar simplex satellite transmitter. The device operates in a very low-power state, waking up on a pre-programmed schedule or when triggered by external alarm or sensor. It then powers the GPS module to ascertain location. The GPS module is then disabled and the simplex satellite modem is turned on to transmit the location data. The modem draws most of its 1.2 amp peak power during a 1.3-second transmission, and is shut off when not transmitting data.

The Globalstar satellite system is a constellation of 48 low earth orbiting (LEO) satellites that relay messages to ground-based gateways, which then pass the call on to the terrestrial telephone network and the Internet. The LEO satellite network also helps reduce power consumption, says Axscend. It requires just 250 milliWatts, compared with the 10 watts needed to communicate with a geostationary link.

Hobbs quotes a maximum cost of £299 per unit, plus a one-off activation charge of £30 and a monthly fee of £7.50 per trailer per month (less for fleets over 100). Extra location "pings" cost 10p per time.

"There is no charge to view the data on the Axscend portal, and you can program the units in-house to get exactly the data you need, including service reminders. Data can be viewed on a desktop or laptop computer, and managers can be emailed of any change in status."

TMC Innovations, which pioneered trailer tracking with Susie-Track, has now launched a new generation which features portable telematics modules, plus a low-cost system called Sky-Track and updated management software.

Managing director Rudolf Buré says power management is the key to reliable in-service performance. The Susie-Track power management system automatically sends the trailer to sleep when it is uncoupled, preserving battery life for up to three months between recharges. Because trailers are often parked overnight hitched to tractor units, Susie-Track wakes up not on recoupling but on the first occasion the driver applies the brakes. "It avoids false alarms."

The rechargeable battery pack is charged through an integrated dedicated charger that takes its power from the (24N) side and rear lights when the outfit is driven with the lights switched on. Alternatively there may be a permanent power feed available on the 24S socket, depending on the make and type of tractor. There is no extra cable between tractor and trailer. The battery pack is continuously monitored. If the power runs low, the unit updates its position less frequently, switching to continue the tracking function for as long as possible.

The latest generation of Susie-Track has a removable tracking-communications cassette that can be switched between trailers. Each trailer has an "intelligent" bracket with a unique identity code, which is mounted internally or externally. The trailer ID is registered in TMC's FleetFacts database, together with the customer reference code for that particular asset.

As soon as the cassette is inserted into the bracket it automatically senses the bracket ID and sends a status report to the FleetFacts Server - comprising the bracket-ID, along with its actual location and time stamp, plus the identification of the cassette. All this information is brought together in the remote database.

"This technology keeps costs down by facilitating pre-installation of assets with brackets, and allowing operators to swap the Susie-Track tracking cassettes from one asset to another," explains Rudolph Buré.

The unit communicates its status via GSM, GPRS, satellite or RF transceiver. The memory stores selected historical data for later retrieval, and can also store non-critical data when the system is in low-power mode. It also acts as a data repository for temporary storage of location data. Susie-Track can store up to 10,000 geofences, and the remote programming feature allows units in the field to be updated over the air; so system settings and geofences can be changed remotely.

Trailer data is downloaded to TMC's FleetFacts server, and operators currently need to have the Fleetfacts software on an office PC to access it and plot locations. However, says TMC, by this summer operators will be able to access the information directly from the server with just an Internet connection.

The five-year lease cost for the full Susie-Track hardware, software and communications package works at around 99p per trailer per day, says TMC. For operators wanting a less costly solution, the company has developed Sky-Track, which costs 50p per day. This low rate is based on a roll-out over a complete vehicle/trailer fleet and includes full installation training, which TMC says is straightforward, plus Fleetfacts software training.

The telematics unit is permanently fixed to the vehicle (either on the body or under the chassis) and there are no extra sensors for measuring functions such as door opening alarms. You get a position update every 15 minutes (every five minutes if you upgrade to the "MB per month" package, which costs £1 per trailer per month).

It does not have the uncoupling/coupling recognition and is not connected via the electrical connection to the tractor unit. Instead the battery is recharged from the trailer lights.

This option is based on a five-year lease contract and includes hardware, software, GPRS messaging cost for location updates every 15 minutes, and Web-tracking subscription. If a more frequent position update is required, an extra £1 is charged per month per trailer for each 1Mb data. The charge assumes that fleets will install their own intelligent brackets, after initial training from TMC.

The full Susie-Track trailer tracking system costs £675 per unit, and the set-up fee on the server. The client software costs £1,750 per PC installation.

Pinpointers has two products for trailer tracking. One is a self-contained trailer unit in which batteries are recharged from a roof-mounted solar panel. The 370mm by 70mm dome is stuck on to a trailer with special adhesive pads. The six-volt power source comes either from the solar cell or from a conventional battery back-up system. There is no external wiring and no modifications are required to the trailer, tractor unit or electrical systems. Operators are able to track loads through Pinpointers' Web-based user-interface.

Asset Alert, a new system from Oxford-based OxLoc, is designed to operate for over three years off two D-cell batteries and provide up to six position reports a day. The data is sent via GSM network to Oxloc's Web site, where users can access their data via a secure password.

GSM is preferred to GPRS for international tracking, says Danny Wootton, a member of Oxloc's business advisory panel. "We are not talking about live tracking, and we can incorporate seven location fixes in one SMS message, so the cost is not prohibitive. Some trailer rental companies only need a weekly position fix, to confirm a customer still has the trailer."

The geofence feature can be programmed to prevent false alarms which might send communications costs rocketing. The geofence can be programmed to operate between, say, 8 pm and 5 am, so during normal depot hours, trailer movements will not trigger a movement alert.

RF solutions

RFID tags for trailers are becoming an option in several vehicle-tracking applications. CS Electronics, for example, now offers TrailerTag as an option on its TrakManager package. The company already has a trailer version of TrakManager, with the telematics unit housed in an IP65-rated rugged polycarbonate housing, designed for external mounting. TrailerTag is a lower-cost alternative.

TrailerTag works automatically without driver involvement, using a passive RFID tag on the trailer unit. Each time the trailer is coupled, TrakManager reads the RFID serial number, then records time/date and location "stamps" relating to the event, adding the data to the vehicle activity data "string". The exact location of each trailer can be viewed on the TrakManager host computer. In addition to audit trails, a utilisation chart is produced for each trailer unit.

Pinpointers too has an RFID option. Either the trailer (or the tractor, for that matter) has an RFID tag that identifies itself to the on-board telematics box or to a wireless LAN at each depot.

A rather different application of RFID in tracking is seen in an intriguing hybrid tracking system called MultiTrack from Intelligent Tracking Systems, which combines GSM, RFID and RF technology. Essentially, it uses mobile phone signals to plot the approximate location of an asset via cell-site identification, then brings the RFID component into play to home in on the asset (down to a metre, the company says).

When a stolen asset has to be tracked and recovered, a specialist third-party direction-finding service is brought into action - or alternatively, users can buy direction-finding receivers and do the job themselves. Depending upon geographical location, conditions and topography, the company says the direction-finding range is from 2 to 4km. If the tracking team can gain elevation above the RFID tag, a range of up to 10km is said to be possible. No special wireless is required for the equipment, the company points out.

The company uses polymer batteries to extend life. It says a standard 1100MAh polymer battery consumes 0.6MAh of power, and will last five days, retaining 20 per cent of battery power as a safety margin.

The full system includes tracking software using Ordnance Survey map data. The on-screen mapping application includes buttons for calling up an asset's current position, last position and previous positions, and can start live tracking, geofence alarms, and switch on GSM and transmitter to activate the RF beacon and movement alert mode.

Another supplier using GSM for the main tracking function, then RF technology for the detailed location-finding, is Podsystem. Here again, a specialist tracking service springs into action when a stolen asset needs to be located, which supplies its systems through a network of resellers. This approach is ideal where stolen assets might be stored under cover because it works indoors, it is not susceptible to signal loss in "urban canyons", and requires no external antenna - all factors that can compromise the effectiveness of GPS tracking.

Typically, Podsystems uses mtrack, a device fitted with a high-power lithium-ion battery with a nominal life of four years. It can be set to send an alarm to the user automatically whenever triggered by its inbuilt motion detector, or activated remotely by the control centre in the event of theft. Podsystem quotes a leasing rate for a single unit of as little as £7 per week.

OEM's latest RF solution is SecuReLocator, which combines RFID and GPRS. "The key problem for many logistics and fleet managers," says commercial director Suzi Jacobs, "is losing trailers within their own network, and suffering the adverse effects on asset utilisation and fleet costs. By monitoring arrivals and departures at depots and even customer premises in real time, fleet operators can identify which trailers are on which site, and monitor turnround times."

Each trailer has an RF transmitter and each site has a cellular hub which collects data from trailers and then communicates the data via GPRS through a VPN (Virtual Private Network) to a secure Web server. The hub scans and detects trailers every minute, and uploads data to the Web site every ten minutes. The data can be directed into the customer's own intranet network or accessed via SecuReLocator software, hosted on OEM's own secure Web site.

"SecuReLocator is designed to minimise the on-trailer cost. Depending on numbers, it can cost as little as £100 per trailer." OEM quotes a rate of less than 15 pence per trailer per day on a two-year GPRS contract. Each hub requires only a standard 13-amp electricity supply, which helps reduce installation costs. OEM says even at a large site, costs rarely exceed £5,000.

Operators in the temperature-controlled sector have another alternative for tracking trailers - harnessing the electronic control unit that monitors and records temperature inside the trailer. Thermo King has pioneered this route, with its R:Com RF tracking system. Data is stored in the Smart reefer electronic control unit downloaded to RF receivers/transmitters when the trailer enters and leaves the depot.

More and more trailers are fitted with electronic braking systems (EBS), and this offers yet another route to trailer tracking. Haldex has been the first to exploit this. Its EB+ unit, which monitors and controls braking performance, also has an interface with a GPS/GSM communications system or RF receivers/transmitter. Trailer data is captured by the EB+ unit and transmitted via this interface, eliminating the need for a separate power unit.

There are now plenty of choices for locating trailers, and with costs falling, "lost" trailers might really become a thing of the past.