In this work, a study of the water level control of an inverted conical tank system is presented. This type of tank has highly nonlinear mathematical and dynamic characteristics. Four control strategies are designed, applied, and compared, namely classical Proportional–Integral–Derivative (PID), Gain Scheduling (GS), Internal Model Control (IMC), and Fuzzy Logic (FL). To determine which of the designed control strategies are the most suitable for an inverted conical tank, a comparative study of the behavior of the system is carried out. With this purpose, and considering situations much closer to reality, a variety of scenarios, such as step responses, random input disturbances, and momentary load disturbances, are conducted. Additionally, performance indexes (error- and statistics-based) are calculated to assess the system’s response.

Most modern vehicles are connected to the internet via cellular networks for navigation, assistance, etc. via their onboard computer, which can also provide onboard Wi-Fi and Bluetooth services. The main in-vehicle communication buses (CAN, LIN, FlexRay) converge at the vehicle’s onboard computer and offer no computer security features to protect the communication between nodes, thus being highly vulnerable to local and remote cyberattacks which target the onboard computer and/or the vehicle’s electronic control units through the aforementioned buses. To date, several computer security proposals for CAN and FlexRay buses have been published; a formal computer security proposal for the LIN bus communications has not been presented. So, we researched possible security mechanisms suitable for this bus’s particularities, tested those mechanisms in microcontroller and PSoC hardware, and developed a prototype LIN network using PSoC nodes programmed with computer security features. This work presents a novel combination of encryption and a hash-based message authentication code (HMAC) scheme with replay attack rejection for the LIN communications. The obtained results are promising and show the feasibility of the implementation of an LIN network with real-time computer security protection.

The increasing local and remote wireless connection possibilities available to common vehicles (such as cellular, Bluetooth, V2X communication) have raised significant cybersecurity concerns. This paper presents an up-to-date compilation about security vulnerabilities present in the most relevant in-vehicle communication buses (CAN, LIN, FlexRay), and a summary of various cybersecurity proposals for CAN and FlexRay, from various authors. Possible cyberattacks on the LIN bus are presented in detail, in order to outline the design of a robust IT security layer for this bus, thereby significantly contributing to the safety of vehicle occupants.

Today’s most relevant in-vehicle communication buses (CAN, LIN, FlexRay) offer no standard cybersecurity features, being highly vulnerable to local and remote cyberattacks, targeting the onboard computer and spreading to the vehicle’s electronic control units through the aforementioned buses. Cybersecurity proposals for CAN and FlexRay have been introduced in the past, from various authors; no such proposal for the LIN (Local Interconnect Network) bus has been presented yet. This paper presents a computationally-feasible, real-time and hash-based message authentication code (HMAC) scheme, for the LIN bus. This proposal provides message integrity check and authentication, and uses a node’s internal timestamp in order to reject replay attacks.