Safety cars: unplugged

When an over eager racing driver tangles with something less than compliant – like a wall – and causes an obstruction on track, the vehicles that fly onto the circuit with lights flashing are known as safety cars. Their job is to back up the racing cars into a procession slow enough that the incident can be safely negotiated while it is being cleared, at the same time as maintaining enough speed for the racing cars to keep heat in their tyres for grip and enough air passing their radiators to keep engines cool.

In F1, powerful and expensive Mercedes AMG SLS supercars are employed as safety cars; in Formula E, they will be replaced with affordable, mass market electric vehicles that are charged wirelessly.   

Who’s behind the wireless stuff?

This is a straightforward answer: Qualcomm Halo. The company is part of the giant US technology firm Qualcomm, which has signed up as a founding partner of Formula E. It’s been working pretty closely on wireless charging tech in performance vehicles for years with electric racing team and land speed record breaker Drayson. (Drayson has, of course, also entered a team into Formula E.)

More recently, Qualcomm Halo announced that it would be running a wireless charging trial using the Renault Fluence. The Fluence is an affordable, mass market mid-sized electric car; Renault is closely involved with Formula E and is part of the consortium building the Spark-Renault racing cars (hence the double-barrelled name). Can we expect to see the Fluence lined up as the Formula E safety car?

Graeme Davison, vice president of technology at Qualcomm, can’t answer that yet. “We’ve spent months working with Formula E,” he tells Current E. “At the moment, we’re looking at OEM choices – which vehicles can or can’t be used. Formula E wants a pure EV, which restricts the choices. But we’ve identified a number of vehicles and we’re close to making a decision. It will be commercially available, but made to look a bit more exciting with some customisation. It ties in with the vision of the series, showing that electric vehicles are here, they’re happening, they’re exciting.”

The short list isn’t yet public, so whether or not the Fluence is under consideration can’t be confirmed. The charging system is scalable and adaptable, however, so it can be fitted to whichever vehicle makes the final cut. “The systems are the same,” Davison explains. “The different cars have different constructions, they are different heights from the road surface (‘Z tolerance’) and so on. But our system will work with all the cars on the list, and we’re finalising our design of that system at the moment.”

The implications of Formula E’s drive towards wireless charging are far more wide reaching than the safety cars alone: the sport wants the racing cars to use the technology too, and as early as the second season. Scalability will be imperative if the system is to be included on the racing cars.

How does wireless charging work?

Wireless charging (also called “inductive charging”) transfers energy between two points by using an electromagnetic field. Simply put, one coil turns electricity into an electromagnetic field; the field then creates current in a second coil, effectively converting the energy back into electricity. Such a system can thus be used to recharge batteries across thin air. Qualcomm Halo’s technology uses multiple coils to achieve a transfer efficiency of up to 90% efficiency and capacity up to 22kW.

In Formula E, Qualcomm plans to first use the technology so that the electric safety cars can be recharged without needing a plug. “The system we’ve designed for the Formula E safety car uses a primary pad, which goes on the ground, and a secondary pad, which is fitted to the car. The safety car doesn’t need a rapid charging system as it will be sat still for most the time, so the system we’ve gone for has a power transfer of around 3kW,” Davison says.

Qualcomm Halo WEVC system courtesy Qualcomm Halo

The primary pad is about a square metre in size, while the secondary device is little bigger than an iPad. Importantly, no permanent roadworks will need to be undertaken to deploy the system.

“The primary pad doesn’t need to be embedded in the road,” Davison goes on. “It simply lays on the ground. It requires no complex infrastructure and won’t require cities to dig up trenches just for race day. What’s more, the system shouldn’t put undue demand on the local power network. It will use a single phase connection, probably delivered at around 16A. It’s a bit like the blue plug you’d find on a caravan site.”

Power transfer would need to be upped significantly if and when the technology finds itself on the racing cars. The current race format will require the 30kWh race car batteries to reach at least 50% charge in around 20 minutes; using a 3kW system would take hours.

Changing role of the safety car

Davison won’t be drawn on the operating parameters of the system that will be fitted to the Formula E safety cars, but he notes that their role may be very different to what we’re used to seeing in conventional motorsports.

“The safety car is used to slow down race cars, but keep them at a speed where they can keep heat in the tyres and sufficient airflow into the radiators to keep engines cool. So traditionally, safety cars have had to be fast and agile. It’s very different with the Spark-Renault racing cars: they have no overheating risk. The only issue is keeping the tyres warm.”

According to Davison, the ability of the battery racing cars to be slowed to a crawl without adverse effects may lead to a complete rethink of how safety car periods are run: “Electric racing cars introduce a new flexibility, because they can be slowed without risk of overheating. However, series organisers don’t want the Spark-Renaults wasting energy by doing numerous non-racing laps, and creeping round the track doesn’t do anything for the spectator experience. There are ongoing discussions between the FIA and FEH to work out if it is better to keep the cars on the track or to bring them into the pit lanes and restart the race from there.”

No conclusion has been reached yet, but in either case the need for a supremely fast safety car is outmoded by Formula E – which is a good job, considering that the Fluence (if, of course, it is on the short list) is no performance vehicle. It has a 70kW electric motor (less than 95bhp), which is enough for it to slither from rest in 13.4 seconds to a top speed of 84mph. Less than inspiring.

However, if the safety car is simply a rolling bus – picking up the racing cars and returning them to the pit lane – then less-than-scorching performance can be overlooked. The car could be modified of course to produce more power, and Davison says that the safety car will definitely get a bodykit and paint job “to make it look like it belongs to the racing scene”. Think DTM, he hints. If the Fluence can be made to look more like the concept version, then they may well be on to something.

Renault Fluence ZE concept courtesy Wikipedia

The number of safety cars at each race will be dictated by the FIA based on track size. Davison states that “there will be one or two safety cars” at each Formula E race.

Safety cars, medical cars and extraction teams

Three types of vehicles will be used to provide on-track safety at Formula E races, according to Davison. In much the same way as other FIA series, in the event of an incident, safety cars will be used to slow the racing cars down and medical vehicles will speed paramedics to the crash site.

While the safety cars will be electric only, the medical cars probably won’t be. “Medical cars are generally provided by the course organisers,” Davison explains. “Formula E just wants the most readily available solution to assure safety in the event of an incident, so it’s likely that these will be ICE vehicles.”

In a departure from conventional motorsports, a third type of vehicle will also be deployed, called an “extraction vehicle”. This will carry a team of engineers who are fully conversant with the construction of the battery-powered Spark-Renault racing car and who are familiar with the dangers and behaviour of high power electrics. Their job is to assure the safety of the medical and marshalling personnel attending a crash site.

In fact, such extraction teams may find their way into other FIA motorsports too. Davison: “We’re seeing increased use of high power electrics in F1 and endurance racing, with hybrids. Battery and electronics manufacturers are doing lots of training courses with marshals. Everyone needs to be as clued up as they can be. Just as we know what petrol is likely to do in the event of a crash, we want to have an idea of what a battery will do in a crash. Everyone needs to be prepared for this new environment: safety is paramount.”

Safety first

This “safety first” theme comes across strongly from Davison. Current E put to him some general reservations about the use of wireless charging, including long term health effects and interference with other nearby electrical equipment – such as pacemakers.

Davison is emphatic that safety will not be comprised by using inductive charging in Formula E.

“Firstly, wireless charging means that teams won’t have to unfasten part of the chassis to plug in power cables or access the battery,” he says. “And with pads in the pit lane, the driver can simply park over the pad and go.”

The charging pads may be positioned in the pit lane to allow for a more efficient charging process – and to allow fans to see the technology at work.

Further minimising risks are two safety systems designed to prevent the electromagnetic field heating up errant metal objects – or frying living tissue.

“The two things we get asked a lot are: what happens if a metal object is dropped onto the pad, and what happens if a cat takes a nap under the car?” Davison says.

Qualcomm Halo FOD screen grab one

There are likely to be plenty of metal items in use in the Formula E garages. Not a problem: Davison explains that a loop array built into the pad continually measures impedance. If something like a spanner comes into contact with the pad, it will alter the flow rate through the loop and the system will automatically shut off.

Qualcomm Halo FOD screen grab two

What about cats (or mechanics retrieving dropped spanners)? “We use radar,” says Davison. “We call it our living object system: devices like car reversing sensors detect when something enters the electromagnetic field and then cause the system to power down.”

Wireless charging system means no exposed cables, and is designed to be impervious to wet weather, too. Important for that London race, even if it will be in June.

So far, so safe. But what about other concerns – such as medical devices?

“I’d hope that Formula E drivers aren’t going to be fitted with pacemakers,” Davison quips. “On a more serious note, there are regulations that define limits we must comply with, such as absorptions rates. We’ve been using the technology for years in the world of mobile phones, and we’ve built up a strong team that fully understands how to work within the parameters. In fact, we’ve been developing our own safety testing plan, working closely with the car industry.”

Going plug free

It’s unlikely that plugs will be fitted for “just in case” scenarios. “Drayson has used no plugs in the years the team has been working with us, without issue,” says Davison. “And when the electric Rolls Royce Phantom prototype went on tour with wireless charging technology and a plug, the plug broke in the socket; the remainder of the world tour was completed using wireless charging alone.”

Introducing plugs or sockets would also add weight and additional points of possible failure, Davison notes, both undesirable in racing scenarios.

Dynamic charging for racing

Joe Barrett is vice president of marketing at Qualcomm and is responsible for helping shaping the company’s strategic direction. He thinks static charging is just the start: wireless charging on the move is around the corner. The potential is for Formula E racing cars to be powered continuously while out on track, yielding unlimited range and avoiding the car swaps of the first season.

“Dynamic charging is ultimately where the technology will go, and our direction is defined by that,” he says. “Our multicoil design circumvents traditional limitations in field and efficiency. Dynamic charging is less efficient that static charging, but FEH was excited by the possibilities that we can open up with the new technology.”

Timescales are rather less clear however. Barrett says that a timeline can’t be put on the introduction of dynamic induction charging to the motorsport, but he stresses that R&D has got a long way into the challenges and solutions.

In the immortal words of the Bachman Turner Overdrive: “You ain’t seen nothing yet.”

6 Comments

Leave a Reply


+ 3 = seven