Brian Hagman of The BRAKE Report recently sat down with Bernd Schemer, Head of Brake Business Unit for Hitachi Astemo, to learn about its brake-by-wire technology they refer to as Smart Brake.
Not too long ago I watched a video that you all produced on the smart brake system. This piqued my interest and I wanted to learn a little bit more about it. Can you describe for us what Hitachi’s Smart Brake system is and what it does?
Bernd Schemer – Before I explain that, maybe just a little bit of terminology. Smart Brake is a brake-by-wire system. At the moment, brake-by-wire is used in the market for different kinds of systems. For example, you have already in the market
so-called brake-by-wire systems which is removing the mechanical link between the driver and the brake but the actuation afterward is still hydraulically controlled. This is also called brake-by-wire but the real next move is to really fully electrically control the system without any hydraulic fluid and that’s our smart brake system. So you have no hydraulic fluid in the car anymore. The system is fully electrically controlled by wires.
Who is this technology designed for? Is designed specifically for electric vehicles or can it work with any new light vehicle?
Schemer – It’s not specifically designed for electric vehicles but it’s more related to cars where you have already a need for redundancy such as level 3+: level 4, level 5. It is a bit connected to steer-by-wire so more level 4. As soon as we have a redundancy requirement in the car we think it is time to talk about the latest standard of full brake-by-wire system.
What are the advantages of using the Smart Brake versus a traditional braking system?
Schemer – There is a large catalog of advantages. Technically speaking, you have an improved brake performance for example a faster time to lock response and based on that, a shorter vehicle stopping distance. You also have an optimized cooperation with the regen braking: you can fine-tune better the regenerative braking functionality and this gives you an increased EV range. Of course, you can enable a higher level of redundancy as I’ve explained and with that, we see it’s part of the set-up of cars with a high autonomous driving level.
Does this system replace any of the foundational brake components like the pads, rotors, or caliper?
Schemer – No, as you know it’s the other way around. Basically, you have four brake calipers which are sitting at the wheel – each wheel a caliper – and then you have a smart actuator at each of those wheels and you take off all the rest of the mechanical components so you have no hydraulic unit anymore (no ESP unit anymore), you have no complex actuation unit anymore. You have a pedal simulator, a ECU somewhere or a software integrated in the central ECU, and you wire it to the four actuators at the wheel, which are in charge to translate the demand from the driver into the corresponding brake torque at the wheel, and you can control each of the wheels independently.
Can this system be used on commercial vehicles? The commercial vehicle industry is definitely advancing in a lot of areas of self-driving.
Schemer – If you mean commercial vehicles like the trucks, that is a different technology. Today, we are hydraulically actuating brakes and this has a range up to light commercial vehicles, very small trucks. From a certain size, you have automatically actuator brakes, this is a completely different technology, this is not our field. We are focusing on applying this for passenger cars, light commercial vehicles, shared vehicles, maybe robot- taxis… and this kind of car set-up.
Is this available today or is it still in development mode?
Schemer – No, it is in development mode. You have seen our video: we have shared our progress to a large number of customers in Sweden. This is not the first time we are there. It is in development, and if you ask when it is going to be launched, we talk about sometime in the second half of this decade for its launch. It’s not really clear yet when exactly but it will surely come in the second half of this decade.
What hurdles or challenges do you anticipate in order to see this being adopted on a large scale?
Schemer – Overall, for brake-by-wire systems, as explained, you need to have a full redundancy: that is one of the key boundary conditions, also in connection with autonomously driving cars. With that set-up, you need to make sure that you have safety and reliability of such systems completely proven, and that is one of the technical challenges which we are discussing deeply internally and with our customers. Of course, lastly, the total cost of ownership needs to be attractive. We need to find a solution that has a value that can be translated by our customers into the value of the car. So these are on the technical side and on the overall attractiveness side the biggest challenges.
Speaking of safety and security, is it possible to hack the system? What measures would be in place to prevent this?
Schemer – For all cars with a higher level of mechatronics and intelligence we have cyber security risks. We are taking this into account in the development work by integrating the standards which are partially defined and are still being further developed. We do this not only from the brake side, we take into account the know-how we have inside Hitachi Astemo as a whole and are deeply discussing that with our customers. This is still developing in terms of maturity and is one of the boundary conditions of the system which needs to be safe and secure from a cyber security perspective.
From the maintenance and repair side, do you anticipate the need for routine preventive maintenance on the system or will there be any special equipment that the repair shops will need?
Schemer – One of the advantages, which I did not mention previously, is the fact that you get rid of the brake fluid which is one of the reasons why you still have maintenance of the car. If you take an EV vehicle today, you actually do not really go to maintenance anymore. And one of the reasons you go is the brake fluid and then the pads maybe. We think that even for the pads, there is a chance to avoid that or at least to limit it much more than what we have today. So there is an advantage to getting closer to a maintenance-free car. On the workshop side, diagnostics and system conditions will be managed by the vehicle, therefore there should be no additional equipment or training required. We believe this is also an advantage from an end-consumer perspective of course. Maybe not so much of an advantage from the workshop perspective. We are all used to maintenance as part of the deal with our vehicles. On other devices, you are not expecting to have any maintenance so to have that vision of a maintenance-free vehicle I think is attractive from the end-consumer perspective.
The Smart Brake is still in different phases as of now, where do things stand or what’s next?
Schemer – We are still discussing and developing this together with a number of customers and we will be in Sweden next year again with an evolution. We have a target to show more serious intent and set up and our aim is to make this ready for production which is our ultimate goal. We started this journey a few years ago and we are still in the engineering development phase but we have a plan to put this in the field in the future.
Watch Hitachi Astemo’s winter testing of the Smart Brake HERE
About Hitachi Astemo
In January 2021, Hitachi Automotive Systems, Keihin, Showa, and Nissin Kogyo completed a business merger and began their journey as the global mega-supplier “Hitachi Astemo”. Through the combined strengths of the companies, we are further enhancing our global competitiveness in the areas of automotive powertrain systems, chassis systems, autonomous driving/advanced driving assistance systems (AD/ADAS), and motorcycle systems.
Hitachi Astemo’s mission is to work on solving various social issues and to create a better future by providing advanced mobility solutions. In addition to reducing traffic accidents and traffic congestion, we aim to reduce the burden on the environment by cleaning exhaust gas and improving fuel efficiency to contribute to the realization of a society that is both people- and eco-friendly.