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New technology innovations from Alfa, Lexus, Renault and Mercedes

By autotech-nath on May 5, 2024

OEMs love their acronyms, almost as much as their suppliers. Unfortunately, not all of them translate well. Alfa Romeos, therefore, are not suffering from stomach cramps but are fitted, instead, with a trick braking system. Alfa calls it the Integrated Brake System, while its supplier, Continental, calls it the rather more ambiguous MK C1.

IBS is as its name describes – several components of the traditional hydraulic braking systems are combined. The vacuum-assisted brake servo is dispatched; braking assistance is provided instead by a pump, powered by a brushless electric motor. IBS also combines the master cylinder (tandem, of course), brake fluid reservoir and ABS/ traction control ECU into one assembly. The main advantage is weight saving; IBS reduces braking system weight by, approximately, four kilogrammes. It may not sound much but every little counts in the race to cut combustion engine vehicle CO2 emissions.

A further advantage of having a high-pressure supply on tap, as drivers who have experienced classic Citroëns with powered brakes will attest, is that reaction times are faster, when the pedal is depressed. This translates into quicker stopping distances.

IBS also features a type of brake-by-wire. While the callipers still rely on hydraulic pressure and not electric motors, the master cylinder pushrod, to which the pedal is attached, does not act directly on a hydraulic piston. Instead, an electronic brake pedal travel sensor detects not just the length of travel

but also the speed of application. The integrated ECUs calculate how much pressurised fluid is needed for each wheel. As a failsafe, the system varies hydraulic pressure to each calliper. As the IBS can adjust hydraulic pressure between callipers, by assessing how the brake pedal is applied, Continental sees this as a vital technology for future autonomous vehicles, over and above the system fitted to the current Alfa Romeo Giulia saloon and Stelvio SUV models. Therefore, the IBS/MK C1 has been used as a platform for progressive development of full brake-by-wire systems, the first production version of which is expected to arrive next year in North America.

Lexus RZ 450e – One Motion Grip

So, brake-by-wire technology is not here – but it is coming. While steer-by-wire has been mooted for years, it still has not arrived – but it could be here sooner than you think. While Lexus has been talking about introducing such a system for years, Nissan beat its fellow Japanese OEM and introduced it on the Infiniti Q50 saloon, although it was forced by legislation to include a mechanical emergency backup.

Now, Lexus has introduced the steer-by-wire on its first sole BEV. The car is not entirely new, sharing its underpinnings with the more common Toyota Bz4X and its sister Subaru Solterra. Both these models are also fitted with non- mechanical steering as an option.

One-Motion Grip sees no mechanical connection between the steering wheel and the rack. Lexus, Toyota and Subarus thus fitted possess a specially-shaped steering wheel, where lock-to-lock has been set to approximately 150 degrees only, between the straight-ahead position and full lock. Toyota says that the elimination of wheel twirling reduces the need for the driver to change hand positions. The lack of a mechanical connection also permits One-Motion Grip greater freedom to vary the steering rack ratio, compared with current systems.

It also prevents undesirable feedback, such as jolts, from being fed back to the driver. Yet, Lexus says that it has paid particular attention not to engineer out all steering feel.

The system is remarkably simple. One-Motion Grip works by steering wheel movement being detected by a Steering Torque Actuator, positioned on the steering column. The resultant data is relayed to the Steering Control Actuator, which controls the steering rack accordingly. Unsurprisingly, other inputs are considered too. This includes speed and even information about the road surface, all of which are received and assessed by the control actuator’s ECU.

While One-Motion Grip is available currently in mainly non- EU markets, it is expected to reach UK-market Lexus/Toyota/ Subaru BEV SUVs by the end of this year, provided that legislative challenges (including if over-the-internet software updates are permitted for the steering system) are resolved.

Sunroofs are falling out of fashion. They have complex mechanisms and are costly. Furthermore, with electrified vehicle weights ballooning, manufacturers are still trying to cut weight wherever they can. Even 30-50kgs of typical sunroof matters. The last thing you want is extra weight so high up, because it upsets the vehicle’s centre of gravity. It is all very well having a panoramic glass roof but the risk is that it turns the car into a greenhouse. Working with French glazing manufacturer, Saint-Gobain Sekurit, Renault has introduced a fixed panoramic roof, made from 50% recycled plate glass, which features electrically-operated shading – no physical blinds are fitted. The options are, all opaque, transparent at the front and opaque at the rear, and vice- versa. The roof can be commanded at the press of a button, or even by voice, through Google Assistant.

The system works, using electrical energy to displace molecules between seven laminated layers, using polymer- dispersed liquid crystal technology. Naturally, the roof is ECU controlled. The glass roof section is designed with nine bands across it, allowing rear occupants to be in the shade, while those up front can bask in sunlight.

According to research released last year by AXA Insurance and the road safety charity, Brake, over 40% of UK drivers admit to switching off various ADAS features (Lane Assist especially), not only because they find them annoying but also they do not believe that they play a positive role to road safety. It is an interesting finding. Yet, manufacturers and governments are determined to burden cars with ADAS technology, especially as the line blurs between technologies that assist the driver and those that take over.

Two years ago, Mercedes-Benz was the first VM to secure approval for an SAE Level Three autonomous system, although for the US market, only. Yet, it is still developing Level Two systems. Its current Active Lane Keeping Assist uses a camera to detect lane markings and edges between 37 and 155 mph and intervenes to avoid unintentional lane departure. Many cars are fitted with similar systems, not always to the driver’s delight, as AXA/Brake’s research confirms.

An extension to this is Automatic Lane Change (ALC), which, on Mercedes-Benz models is part of the Active Distance Assist DISTRONIC with Active Steering Assist. Should the ADAS hardware detect that the vehicle is approaching another one between 47 and 87mph, it will change lanes, instead of just slowing down. The system must have detected that road lines are consistent with those found on dual carriageways, the road must have a speed limit and the car must have active route guidance, with MBUX Navigation. The system requires no further driver input to execute the automatic lane change. However, Mercedes-Benz insists that, being a SAE-Level 2 system, the driver’s hands must remain on the steering wheel.

ALC is available in North America and Canada, but Mercedes-Benz is expected to roll the system out in Europe later this year, fitted first to the new E-Class.

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