By: STMicroelectronics
Over the years, ST has multiplied the AutoDevKit development boards for motor control applications in cars, which all have a name that starts with “AEK-MOT”. There are general systems like the AEK-MOT-2DC40Y1 for driving three DC motors, the AEK-MOT-3P99081 for brushless motors, and the AEK-MOT-SM81M1 for stepper motors. There are also more targeted approaches like the AEK-MOT-TK200G1 for powered liftgates or the AEK-MOT-WINH92 for powered windows. The reason behind this broad range of solutions is that engineering needs in cars are changing, and as applications become varied, so must the solutions that address them. Let’s explore how those who make cars are looking at them differently.
How the car has changed
Challenge 1: Application diversification
While many talk about the electrification of cars or the advent of AI in vehicles, there’s one trend that many overlook. In a span of a couple of decades, vehicles went from having about ten or so motor control applications to close to 50, and we are going to reach a hundred in a few years. The reason is simple: as cars become more digital, replacing a basic mechanical system with a motor control application means greater safety and the ability to add smart features. There are popular examples, such as powered windows, doors, or trunks. There are also systems that many drivers are oblivious to, like active suspensions, electric braking and power steering, EV drivetrains, new actuators, and more.
Challenge 2: Architectural transformation
Moreover, the underlying foundation of the car itself is going through a major shift as many adopt a zonal architecture. In essence, it means that engineers organize electric control units based on their zone or physical location instead of just grouping similar features together. It has the advantage of simplifying designs. In some cases, moving to a zonal architecture helped reduce the overall harness weight by 20%. It also means that engineers can use much more powerful computing systems, leading engineers to use an even more diverse range of motor control applications as they infuse artificial intelligence in more parts of the car.
The need for new motor control applications
This trend comes with two significant challenges. The first one is that as more diverse applications use motor control systems, OEMs need different motor drivers and motor types. Some also wonder whether they need an integrated or non-integrated solution. Simply put, as the kinds of applications become more varied, teams struggle to find new solutions to meet their needs. The second challenge is that designers are looking at cars differently. The move to zonal architectures means that more diverse systems must easily interact with one another. Put simply, teams are increasingly looking at the vehicle as a whole rather than the sum of its parts, and they need solutions that can meet this new global vision.
AEK-MOT or how to keep up with the changes
A comprehensive ecosystem
Another challenge is that each automated component must talk to the central unit, which means dealing with numerous interfaces. Currently, some systems prioritize SPI, while others use LIN, CAN, 100BASE-TX, 10BASE-T1S, or something else entirely. As engineers look at the car more globally, they are demanding motor control systems that can work with both new and existing interfaces. How a motor control application implements these systems also matters. Are they integrated or not? Does the SDK make one more accessible than the others, and can abstraction layers help solve these issues? This is why our AutoDevKit ecosystem includes varied development boards and a software library to take advantage of them more easily.
Furthermore, to enhance the transition towards software-defined vehicles (SDV), ST has developed an additional AutoDevKit functional block, AEK-COM-10BASET, that acts as a gateway between the legacy protocols found in most motor driver ICs and the new trendy 10BASE-T1S. The latter is a key building block for the new Remote Control Protocol (RCP) specification currently in progress (Open Alliance – TC18 Remote Control Protocol), which uses native Ethernet frames on 10BASES-T1S for deterministic performance. In essence, RCP is an intermediary between the Ethernet physical interface and SPI or I2C to access registers or talk to the microcontroller.
Non-integrated
The AEK-MOT-2DC40Y1 can drive up to three DC motors, two bi-directional in parallel or three with proper sequencing. It features VN7 high-side switches and the VNH704AY integrated H-bridge motor driver. The documentation shows how to set up the motors and the configurations available. Additionally, developers can use the graphical user interface in AutoDevKit to manage rotation direction, start them, increase or decrease their speed, and more. The AEK-MOT-2DC40Y1 connects to an SPC5 MCU board, meaning integrators can rapidly design a proof-of-concept. Similarly, the AEK-MOT-SM81M1 also connects to an SPC5 board but features the L99SM81V stepper motor driver, while the AEK-MOT-WINH92 for window lifts uses the L99H92.
Integrated
The AEK-MOT-3P99081 focuses on CAN-controlled brushless motors. It is an integrated solution with an SPC560P microcontroller and the L9908 gate driver. The MCU talks with the driver through an SPI interface for easy access to configuration options, protection features, and diagnostic messages. Similarly, the AEK-MOT-TK200G1 for powered liftgate runs on the SPC582B60E1 microcontroller and the L99DZ200G drivers, which supports LIN and HS-CAN interfaces for MCU programming during production. Developers talk to the board using a CAN bus to make it easier to access the motor remotely, meaning from another domain controller. Avid readers will remember it was at the center of our AEKD-TRUNKL1 demo.
All in all, the comprehensive aspect of the AutoDevKit ecosystem means that the learning curve gets easier as teams use different AEK-MOT development boards. They get a range of integrated and non-integrated solutions that all work together under one ecosystem. As a result, everyone, from the decision-makers to the engineers building the platform, can more easily look at the car as a whole and see how all its components can come together under one overarching system. This means that ST is uniquely positioned to become a one-stop shop as more and more motor control applications transform vehicles.
