Tec team develops modular EV with Android-based control ecosystem
17 July 2017
A team at the Monterrey Institute of Technology (Tec) in Mexico has developed an electric vehicle featuring modular design, multimotor, power source, digital control, autonomy, and connectivity—the EvTec project.
In an open-access paper in the journal Advances in Mechanical Engineering, the EvTec team discusses the use of the Android-based Control Ecosystem, which integrates the Operating System Android, as part of the open-source control of the vehicle. The The objective is to design a platform that enables connectivity with the cloud for monitoring and remote controlling purposes.
New cars are equipped with a fixed set of software and hardware, which in most of cases cannot be upgraded once vehicles leave the factory floor. Nowadays, the way in which people interact with cars is shifting toward a more customizable experience, much more similar to what a smartphone can offer. Update/ upgradeability and ease for customization are features that need to be considered in vehicles and in many commercial products, for example, in home appliances. Every automotive designer is aware of these issues, and efforts have been made to implement OSs of mobile device for infotainment and navigation. At the same time, recent studies suggest that mobile device OSs, and in particular the open source, universally available Android OS platform, can be used for more critical functions. For example, the use of sensors for safe drive, the interfacing for the powertrain control, and the use of apps to tune suspension, brakes, and/or steering systems1 are all examples of feasible uses of the mobile device characteristics in the vehicle domain.
… This research project analyzes the performance of a platform that connects an electric vehicle with a remote server using a mobile device, which in turn is in close communication with the vehicle controller. Performance information such as the sending/receiving frequency, data losses, communication delays, and reliability of the system is analyzed for a first level (Level-1) vehicle connectivity: vehicle monitoring. Testing was implemented in the powertrain and steering systems of the EvTec prototype, a modular electric vehicle. The ultimate goal of the EvTec project is to provide a test bench for an original approach toward the paradigm of connectivity and autonomous driving. Two more levels of connectivity are defined and discussed: (Level-2) vehicle monitoring with sending/ receiving warnings and (Level-3) vehicle monitoring with remote control.
—Coronado et al.
|The modular architecture of the EvTec design includes five main modules. Coronado et al.|
The central part of the control system is the controller that comprises eight 32-bit cores. The controller is responsible for three main functions: (1) data acquisition, (2) sending signal to actuators, and (3) communication with the mobile device.
Data acquisition is focused on two main sources of information from the electric vehicle: (1) the speed of the two electric motors of the powertrain and (2) the position of the steering wheel.
The project considers three levels of operating conditions to validate the performance of the connectivity for vehicle control purposes.
In Level 1, the vehicle controller generates a signal to control the accelerator of the powertrain which is sent to the controllers of the electric motors. A signal to control the steering system (g) is also generated and delivered to the controller of the stepper motor installed in the steering column.
Level-2 consists of basically the same processes of Level-1, but the remote host analyzes the information received and decides whether or not to issue a warning, for example when a speed limit is violated. This resembles a V2X use case.
For Level-3, the control signals are generated in the remote host and transmitted to the vehicle controller through the mobile device. This level resembles a full remote control situation.
Future work consists in the testing of Level-1 connectivity in various conditions, closer to real driving operation. Other subsystems of the vehicle can be added to the monitoring function, for example, status of battery charge. Future work will also focus on achieving Level-2 and Level-3 connectivities, which consist respectively, in monitor the vehicle and remotely send warnings or control commands to the vehicle. This connectivity could help provide support for local sensors and processing in the case of autonomous driving.
—Coronado et al.
Pedro Daniel Urbina Coronado, Horacio Ahuett-Garza, Ruben Morales-Menendez, Pedro Orta Castañón, Luis Daniel Dávila, Mendoza Rubén Flores Escalera (2017) “Connectivity of a modular electric vehicle by the use of a mobile device,” Advances in Mechanical Engineering Vol 9, Issue 7 doi: 10.1177/1687814017708087
Pedro Daniel Urbina Coronado, Horacio Ahuett-Garza, Vishnu-Baba Sundaresan, and Ruben Morales-Menendez (2015) “Development of an Android OS Based Controller of a Double Motor Propulsion System for Connected Electric Vehicles and Communication Delays Analysis,” Mathematical Problems in Engineering Article ID 467165 doi: 10.1155/2015/467165