JLR’s Pierre Garnier on the State of Braking Today

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COVENTRY, U.K. — Pierre Garnier, Senior Manager – Head of Brakes Engineering for Jaguar Land Rover, recently discussed with The BRAKE Report his functions at the automaker as well as his thoughts about today’s automotive environment and how it is impacting his area of responsibility.

What is your current role and area of responsibility?

My current role is Senior Manager of Brakes Engineering at Jaguar Land Rover.

My responsibilities cover customer braking attributes, system and component design.

Pierre Garnier
Pierre Garnier, Senior Manager – Head of Brakes Engineering for Jaguar Land Rover

What can you tell us about your background? Have you always been in or around braking?

I started my engineering career in body engineering, but the majority of my background is in braking, with 18 years of experience. I started this journey in September 2003 at Renault-Nissan and developed experience through different projects. I occupied different roles from project component engineer to senior engineer on all brake commodities from upstream to Job #1. I was also leading system design and new brakes technologies to support the company’s electrification strategy. 

I joined Jaguar Land Rover in 2014, looking at upstream system definition. I then created and led a brakes system architecture team before moving into my current position.

How would you describe your work/leadership style and why has it worked so well for you?

First of all, I’m convinced that to lead an engineering team there needs to be a balance between expertise, passion/purpose and operational discipline. I have acquired expertise of brakes engineering science and technologies through my different roles. Also, over the years I have been lucky to work with talented people, both internally and externally. This has given me different perspectives on common themes and challenges. On the operational side, starting my career with engineering mass market cars and then moving to a prestigious, premium OEM has instilled an emphasis on rigorous business commitments (on cost, timing, and quality) in me as well as a focus on the customer.

What particular challenges do the move to both hybrid and battery-electric vehicles present to designers of braking systems?

Thanks to regenerative braking, EVs are not perceived as needing as robust “mechanical/electronic (traditional)” braking systems as ICE or hybrid-electric vehicles – is this perception accurate?

The electrification of the propulsion system (hybrid or BEV [battery-electric vehicle]) gives both opportunities and challenges to the braking system, at the same time. First of all, to enhance vehicle efficiency, electric motors also work as generator to harvest the kinetic energy of braking into the battery to extend range. This is what we call ‘regenerative braking’. Historically, and on the first BEV vehicles, OEMs only introduced regenerative braking on accelerator pedal lift off, but they have now switched or expanded it to include brake pedal application in order to optimize usage coverage. In those cases, the brake controller needs to deliver the driver braking demand between the friction brake and the electric motor. This requires a robust and accurate control between the brake system and the electric motor to ensure that the targeted electric deceleration is delivered to avoid under or over braking. Also, the capacity of the regenerative braking performance of the electric motor could be affected by different factors such as temperature, speed or level of battery charge, for example. Consequently, the brake system should always know the available amount of regenerative braking before requesting to blend or offset it with friction braking.

In some ways, we can understand that the duty cycle and energy in friction braking could be reduced, and the design can be optimized in comparison to conventional vehicles. However, in practice, this is not true. Firstly, regenerative braking cannot currently cover the braking power or energy capacity of the friction brake for high deceleration or repeated/prolonged braking to satisfy safety sign off standards. Secondly, BEV or PHEV vehicles are usually heavier compared to ICE vehicles due to the weight of the battery pack. Some OEMs have also taken the opportunity to market BEV acceleration (0 to 60mph), to pull the market in that direction. This means that the system deals with more kinetic energy. So, to answer the question, EVs need the same or a better level of robustness for the mechanical or the controls. We’ve seen that brakes systems become more intelligent and integrated, and friction brakes need to be designed for the worst-case scenario which could be more demanding than ICE braking systems.

Jagaur I-Pace

Considering the impact of CPUs, electronics and interactive software on all automotive systems, especially ADAS and autonomous driving characteristics, what unique challenges does the chip shortage today and the potential of additional ones in the future put on brake-systems designers? How might these issues impact the type of braking, ADAS and AV systems we see in future vehicles?

If we look back on the automotive industry over the last 50 years, it has transformed most of the features and functions that were delivered mechanically; most of them are now assisted or automated. On top of that electronic evolution, we have added digital or connected features for safety, comfort or environment. This has resulted in an increase in required computing power and the numbers of dedicated ECUs in cars, and therefore an increased demand in chips. It appeared that, in general, the automotive industry’s management of the chip supply chain was highly exposed due to limited forecasting and the volatile demand caused by the pandemic. OEMs and suppliers have tried to manage it in order to keep building and selling cars. Some of them have removed features, but this is simply impossible to do in primary safety functions such as braking. Changing chip source is leading to long validation processes and is essentially moving the problem from one area to another.

We’ve seen earlier that the brakes system is functionally integrated with the electric propulsion system. This is the same with the ADAS system when braking delivered through autonomous emergency braking or cruise control. However, this has been delivered through separate and bespoke ECUs for most OEMs.

Therefore, the chip shortage will push OEMs for greater integration to increase function density and minimise the number of ECUs and chips. In that scenario, the remaining ECUs will have to support standard requirements and demonstrate resilience to perform safety-critical functions.

The U.S. is restricting copper and other heavy metals within friction materials; the EU and U.K. is working on restrictions/regulations concerning brake emissions – what challenges do these pollution standards present to engineers like you? How will these type of regulations impact the types of braking systems we might see in the future? Do we have technology now – or visible on the horizon – which can meet these types of regulations and still allow braking performance we expect in a modern vehicle?

The environment is becoming a factor in the design of brakes systems. We talked about efficiency and energy recovery earlier on, but the industry is facing issues with regards to brake dust emissions and with the reduction of tailpipe emissions, the focus has shifted to brakes.

I think the regulations to limit emissions and to restrict or prohibit certain materials is a good thing, and we need to embrace the challenge to make our systems cleaner.

If we look at the journey of the powertrain with regards to tailpipe emissions, we can see some similarity on the type of solution being looked at by the braking industry. One solution consists of applying active or passive capture to collect the emissions in the same way as tailpipe engineers applied catalytic converters in the 1990s. Those solutions are at the concept phase and OEMs see challenges for integration and customer impact when filters are full. Another solution consists of replacing brake disc by drum brake and to use the drum to collect the emission. This could be done when braking energy involved is low and/or on electric driven axle. However, this doesn’t address the problem at source fully and could displace the problem at the maintenance point.  Instead, brakes engineers are looking to improve the brake friction couple (friction pad and disc) to emit less at source, in the same way as powertrain engineers improved combustion in the past. This translates into a developing a new low wear friction pad material with a less abrasive compound. For example, non-asbestos organic (NAO) pads already exist and are widely available but might require a different overall system design strategy to optimise the best operating window. The removal of copper from the pad for the US is also challenging for the thermal performance and friction stability and needs a system approach to maintain braking performance.

On the disc side, one solution consists of hardening the rubbing surface by applying a different metal coating to reduce abrasiveness from the friction pad. The solution already exists but it is currently expensive, and the industry is working to find affordable alternatives that will be available soon.

Finally, regenerative braking, as we discussed before, is a key contributor and could be seen as the ultimate solution: no friction, no emission. A lot of recent BEV vehicles demonstrate the ability to cover the majority of braking applications. This solution exists and OEMs are pushing to develop this further from an overall efficiency perspective.

As we can see, solutions exist already, and some OEMs have been proactive; we can expect further developments in the near future. The level of adoption and implementation will also depend on future emissions regulation limits.

Jaguar Land Rover

What sets your company apart from your competitors?

We are a premium OEM, with distinct brands. We must be excellent at the basics and deliver the best, balanced braking attributes. We have been at the forefront to deploy the right brakes technology to meet our customer’s expectations. For example, we have rolled out a decoupled brakes architecture on nearly all our products. This has offered best-in-class autonomous emergency performance, brake pedal feel, and actuation refinement, even when delivering regenerative braking. With the pedal being decoupled during braking, it removes all pedal disturbances. First of all, during ABS intervention the intrusive pedal tactility is removed as the modulation valves are located in the wheel circuit disconnected from the pedal. This is a must for our vehicle capability during off road driving. Also, during automatic interventions such as Cruise control, the system can self-generate hydraulic pressure to decelerate the vehicle and the pedal won’t go away. Additionally, if the driver presses the brake pedal at the same time, there is no inconsistency in pedal feel. At the wheel end, we have been working on and implementing friction material to minimise noise disturbance and brake dust emission since 2014, while still offering customer performance for braking. We are dedicated to using this foundation to further develop our technical strategy.

What are the best opportunities for the company?

We have announced through our Reimagine strategy that all Jaguar and Land Rover nameplates will be available in pure electric form by end of the decade. This will allow us to deploy our learning from recent electrified propulsion developments for regenerative braking (including MHEVs, PHEVs and BEVs such as I-PACE) to maximise efficiency and a reduction in brake dust emissions.  

Tell us something that most people might not know about you or your organization.

I would like to reflect on the last two years, especially in the context of the pandemic and what it meant for the team. Obviously, this has been a hard time for us and our community. The majority of people in the team have been working from home, everyone has had to respect work-life balance, with parents having to run home schooling while also running meetings and projects at the same time. We had to reshuffle our diaries and set up daily touch points to check team members were safe, providing support when required as we’ve seen people struggling mentally with being isolated. Also, one of the team’s responsibilities is to sign off systems, either on rigs or on vehicles. For those with this responsibility, it has been a challenging time to get testing done with social distancing and Covid-19 rules in place to maintain health and safety on site. We therefore had to be creative during lockdown. For example, we were able to run remote homologation witness testing with the authorities by fitting cars with cameras to show the manoeuvers and instrumentation data broadcast live to official assessors sitting on a sofa with a laptop rather than being on the passenger seat! All of this dedication and the willingness of the team to support each other allowed us to deliver on our commitments. I’m so grateful to the team and really proud of what we have overcome together during this difficult time. This has been a truly collective effort and an experience that has made us a stronger team than ever.

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The Brake Report
The Brake Report

The BRAKE Report is an online media platform dedicated to the automotive and commercial vehicle brake segments. Our mission is to provide the global brake community with the latest news & headlines from around the industry.