Today’s human-machine interfaces (HMIs) provide the link between sophisticated technology and the human touch required to effectively operate essential systems and applications. By offering intuitive contact between the operator and the process, users can safely operate trains, build cars, produce manufactured goods, or machine critical industrial parts, for example. Performance advancements continue to drive new embedded designs in these arenas, and HMIs are evolving in step. Integrating HMIs with control systems is proving valuable in many embedded sectors, with the fastmoving, global transportation market leading the charge.
Characterized by diversity within systems and applications, transportation solutions range from operator controls to passenger-facing systems. Expectations of service and versatility are on the rise, and designers need to think well beyond merely satisfying longevity, low-power, and extreme processing demands. Applica tions today include a variety of wireless interfaces such as Wi-Fi, GSM/3G, and GPS; resulting designs must function with high electromechanical reliability and a minimum number of system cables. Yet too many individual systems can increase maintenance and its associated costs, and can complicate the process of data acquisition and network control. The challenge for designers is to integrate the functionality of multiple systems in a way that maintains performance and does not sacrifice safety. Transportation Applications
Drive HMI Evolution
Many control systems in transportation environments require a graphical user interface, a challenge compounded by ongoing exposure to shock, vibration, and extreme temperatures. Visual systems are, in fact, vital to train control, with complex displays delivering information and visual feedback about the ongoing operational condition of the line. For example, during a typical trip, an HMI displays route progress and schedule (planned and actual), telemetry information (speed or system status), or a crew warning when approaching speed restrictions or potential hazards, such as a crew working on tracks. In response, a user can change speeds, update the schedule, and make announcements to the passengers.
Reliability and long-term deployment are essential priorities, along with high-performance processing that incorporates any number of real-time data sources. For example, systems that provide passenger information are exposed not only to the elements, but also to a much more rigorous environment of shock and vibration than an interface at a stationary bank kiosk or ticket counter. Ideal systems also provide enhanced graphics and a continuous upgrade path for OEMs — pointing developers toward customized COTS products and platforms, and an increasing focus on converged HMI systems that leverage standards-based technologies.
Meeting Today’s Application Needs with HMIs
While earlier generations of HMIs were effective as the principal point of contact between users and systems, they were considered primarily display technologies. These separate displays or touch screens connected with a USB interface to a central computer, which in turn connected to an I/O box or networked system. Cabling was more extensive and system footprint was expanded with multiple components, establishing a greater number of potential failure points and limiting applications that required more physical space in the cab. Most importantly, these multiple interfaces resulted in more complex implementations, in turn reducing reliability and increasing maintenance and overall cost of ownership.
Today’s HMIs are functionally similar, connecting operators and systems with intuitive features and design. The shift, however, is in the convergence of HMI and control systems. By integrating display functions with control systems, transportation OEMs can offer a more simplified system implementation with improved reliability. For instance, modern railway driver consoles and dashboards use intelligent display computers in an environment very similar to airplanes, where these devices function as digital instruments and information systems for the driver. Converged units can be retrofitted into smaller spaces, and now include network and I/O boxes, video, and a range of RF interfaces, eliminating the extreme maintenance requirements common to previous implementations based on separate system components.
The Kontron HMITR, for example, is a converged system that features an application-ready rugged display integrated with a control computer. The setup allows designers to streamline a broad spectrum of operational systems and passenger-facing systems, ranging from ticketing and outside information, such as destination details, to inside features like audio communication to passengers and fleet dispatchers, advertisements, driver identification, navigation, travel recording, or on-screen schedule updates.
Converged Systems Increase Reliability
These converged systems also leverage a modular approach, simplifying the ability to swap out different power supplies, I/O boards, video controllers, or any component that is specific to the application itself. Transportation designers have a semi-custom product, grounded in COTS design but with all the specific interfaces and exact functionality required for certain applications.
Control systems are contained within the display box, and a converged system is now defined as a display and touch control system. Processing occurs within the system itself, made more powerful by additional I/O enabled, in the case of the HMITR, through an Atom E600 processor architecture, along with any specialized I/O boards incorporated as part of the application requirement. System elements that were once implemented as discrete units are rolled into an HMI interface. Modular layout permits customization of features such as GPS, GSM, GSM-R, LTE, Wi-Fi, MVB, WTB, and other interfaces. For example, a high speed/high capacity train cockpit could be readily equipped with four HMITRs to manage multiple applications, while the dashboard of a metro train may require only one or two HMITR devices.
Converged HMI and Control System Implementations
Typical HMI-based railway applications include Driver Display Systems (DDS) that must meet UIC 612-0x standards. Other applications include supporting diagnostic and control functions, such as Train Radio Display (TRD), Technical and Diagnostic Display (TDD), Control and Command Display (CCD), and Electronic Timetable Display (ETD).
One such example of a centralized system is the Kontron Venturo, implemented for a public bus operator servicing various related cities and regions. The operator has committed to using new technology to improve passenger services. Its buses are uniformly equipped with a ticketing system and optionally include a broad range of onboard equipment such as CCTV, an SMS dispatch system, support system operations, communication, and GPS. Sophisticated features include the ability for passengers to receive SMS text messages alerting them to traffic disturbances or delays of individual buses.
Venturo’s central server is called CBox, which manages all in- and outbound data. It interfaces to the vehicle through galvanically isolated digital I/O and serial lines (including a higher IP65 environmental protection rating), and to the “outside world” by integrated GSM and WLAN interfaces. The Venturo HMI is networked to the CBox, and provides fare information and tickets to the passenger, while providing application-specific software menus to the driver.
HMIs Moving Forward
There are many very human characteristics that are inherent to operating public transportation systems: reaction time, ability to multitask, propensity for visual vs. audio cues, and attention span. As a result, HMIs have a critical role in transportation design, offering clear functionality and streamlined controls that in turn enable the highest levels of safety, performance, and efficiency. These same requirements hold true for police and rescue vehicles, fire brigade, and command trucks, and high-performance public transportation applications such as data gateways for railways, video surveillance in buses, or trams.
Expertly designed controls reduce errors and ensure passenger security, establishing the most intuitive and functional link between man and machine. Converged systems skillfully align with this design strategy — reducing costs, eliminating complicated maintenance, increasing reliability, and creating a forward path for streamlined high-performance transportation systems.
This article was written by David Pursley, Product Line Manager at Kontron (Poway, CA). For more information, Click Here .