Electronic engine displays

Analog instruments displays have long been standard for displaying engine operation information. However, engine manufacturers are now offering new ways to present engine data. This new approach, borrowed from the aviation world, uses cathode ray tubes to provide a mix of information that can be customized by the operator of the vessel.

Power boat instrument panels are usually dominated by a display of analog engine instruments. Twin-engine boat panels exhibit strong vertical symmetry: the instruments are often arranged in a horizontal row. This panel design is just about the worst possible arrangement for the various gauges. The wide horizontal separation makes it difficult to rapidly compare like gauge readings for the two engines. The engine instrumentation usually includes an alarm systema light and buzzer to announce overheating of the engine’s freshwater cooling loop or near-zero oil pressure. On alarm activation, the helmsman must scan all of the gauges, determine which one is showing something out of the ordinary, and take action.

Fortunately, power boat instrumentation is evolving into forms resembling the latest in aircraft technology, bringing with it ergonomic design, enhanced status enunciation, and interactive displays.

Two stimulants are driving the evolution from mechanical gauges to electronic displays. In one case, the introduction of computer-controlled engines makes the use of electronic instruments, driven from a serial digital data bus, very attractive. Second, a computer can process and display data in whatever format is appropriate for the current operating condition. In either eventdiscrete instruments or computer software-derived displaythe massive reduction in wiring between engine room and bridge and is very attractive.

In aircraft, the systems works like this: When operations are normal, only minimum information is displayed; all other data is intentionally suppressed since it is of no immediate value to the crew. Upon detection of a problem, the computer program automatically alerts the crew and displays the data set needed for analysis and troubleshooting. This “if it ain’t broke, don’t fix it” approach to data display is well proven. Applied to a boat, such a system might display only engine rpm when everything is operating properly. If something abnormal is detected, all of the information appropriate for the analysis would appear on the screen.

Caterpillar’s approach to engine instrumentation is illustrative of industry trends. For their computer-controlled marine diesel engines, Caterpillar offers the buyer three instrumentation options in addition to conventional analog gauges. The three electronic instrumentation options are: Electronic Monitoring System (EMS), Computerized Engine Monitoring System (CMS), and the Engine Vision System (EVS), a marinized/hardened, PC computer-based, data analysis with LCD.

Of the three non-traditional options, the Electronic Monitoring System (EMS) is closest to the use of conventional gauges. It is composed of three display modules, each measuring just over four by five inches. One module is the Tachometer Unit, which shows engine rpm on an analog display, with vessel speed over the ground (from a connected GPS navigator), engine synchronization status, and trolling valve status shown digitally near the bottom of the display. The Quad Gauge Unit provides four analog instruments: engine oil pressure, engine coolant temperature, transmission oil pressure, and transmission oil temperature, each with integral warning alarm. Integration of the alarm indicators in each gauge greatly simplifies identification of the source of an alarm. The remaining module in the EMS is the Main EMS Unit, which provides 10 warning lamps dedicated to power system diagnostics. A digital display at the bottom of this unit allows the user to scroll through the following parameters: engine oil pressure, engine coolant temperature, transmission oil pressure, transmission oil temperature, engine speed, engine hours, fuel consumption rate, and percent power load for the engine. Clearly, the EMS is a step above the capability of any conventional gauge group.

Integrated display approach

The next step in instrumentation is the Computerized MonitoringSystem(CMS).Inthissystemallof the displays areintegratedintoasingleseven-inch-long,five-inch-high module. Six analog gauges occupy the left side of the display: oil pressure, coolant temperature, boost pressure, transmission oil pressure, transmission temperature, and percent load. Any out-of-range parameter causes the gauge associated with the measurement to flash, aiding rapid identification of a problem. An analog tachometer, with indicators for synchronization mode and trolling mode occupies the center of the module. A two-line digital display beneath the tachometer dial can show engine rpm, oil pressure, coolant temperature, boost pressure, percent load, and transmission oil pressure or temperature. The right side of the module is occupied by a 12-channel diagnostic display.

The most advanced of the three Caterpillar instrumentation options is the Engine Vision System (EVS). It is composedofa marinized/hardened PC computer with a color, touch screen, LCD display operating from custom software. The display screen is 8.3 by 6.2 inches, with a resolution of 640 by 480 pixels. One EVS suffices for single or multi-engine vessels. As might be expected from a software-driven system, the user has a wide choice of displays. Regardless of which screen is selected, all caution and warning conditions are enunciated within the parameter’s gauge display. Color backgrounds for the digital data change color, yellow for caution and red for warning. Immediate identification and troubleshooting with this system is excellent. Invalid signals from a sensor is also shown, which can save time and money.

In addition to the four-gauge screens, the system offers a diagnostic screen, which provides a plain-language commentary about a detected fault and a set of recommended corrective actions. A maintenance screen displays all of the recommended periodic maintenance items and their normal intervals. A navigation screen is available for vessels equipped with an interfaced GPS navigator. With this screen in use, the most basic engine parameter, rpm, is shown in both analog and digital form, with vessel SOG in bar-graph form and other navigation data (latitude, longitude and heading) in digital form.

Time-related data

The EVS can also display a set of histogramstime-related displays of various engine-related data that have been collected and stored in the memory. There are four history screens for each engine: speed trip, speed lifetime, load trip, and load lifetime. An additional screen shows engine lifetime histories. The wealth of time-, speed-, and load-related engine information can prove invaluable when troubleshooting problems or when evaluating overall engine condition. The use of computer software for systems monitoring is cleverly applied by RGM Information Systems in their Integrated Shipboard Information System (ISIS). In this instance, the monitoring capability can include up to 1,600 functions. The massive monitoring and display capability of the ISIS makes it attractive for large yachts. On large vessels, and occasionally on even small boats, electromagnetic and electrical interference with sensor signals can become a hazard. The ISIS response to this problem parallels current aviation and missile technology with the use of fiber-optics to carry signals from sensors to the central system. Electrical signals are converted into optical form near the point of origin and sent to the remainder of the system via optical fibers that are immune to virtually all external interference sources. The system is modular and can be configured to manage a very wide range of vessel requirements. Multiple data display units can be used. In addition to its use when underway, ISIS can also function as a vessel security system. In this mode, it integrates information from video cameras, motion and infrared detectors, intrusion detectors, temperature monitors, and tank and bilge level monitors. System status and conditions on board can be monitored remotely, with a computer modem communicating by hardwire or radio link. The system can even function similarly to the LoJac automobile anti-theft tracking system.

There is one criticism deserving of both the Caterpillar EVS and ISIS instrumentation systems: the long axis of both displays is horizontal. Orienting the displays vertically, as in modern aircraft cockpits, would improve panel layout. Still, compared with traditional powerboat instrument panels, any of the systems described are a great step forward.

Contributing editor Chuck Husick is a sailor, pilot, and Ocean Navigator staff instructor.

By Ocean Navigator