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CONFIDENTIAL POSITION REPORTING SYSTEM SHOWCASEOverviewThis showcase describes the prototyping and productionisation of the RNLI Confidential Position Reporting System (CPRS) fishing safety product which provides vessel monitoring, tracking and man-over-board detection. Business caseMany lives are lost at sea due to fishing related incidents including man overboard incidents and sinking fishing vessels. It is common practice for skippers not to openly divulge their fishing locations, therefore in the event of difficulties, search and rescue operations can be seriously hampered and in the worst case lead to unnecessary loss of life.  The RNLI conceived the idea of a Confidential Position Reporting System which tracks the position of fishing vessels and monitors man-over-board status of on-board personnel. SolutionThe system breaks down into two main parts; a central server and vessel mounted equipment:
Raycomm’s involvement in the project was to develop the hardware and software for the vessel mounted equipment and man over board detection units: Proof of Concept PrototypeThe main challenge in developing the vessel mounted equipment was to reliably detect man overboard events. False alarms are unacceptable and failure to detect a man overboard incident would be much worse. Raycomm were commissioned to devise an evaluation system that would determine whether Bluetooth could be used to reliably detect such events and report on findings.  Extensive Bluetooth coverage testing on fishing vessels of various constructions showed that Bluetooth could be used for the application, providing the Bluetooth antennas were suitably positioned on the vessel. An added bonus was that Bluetooth is a mature, proven and cost effective technology to build into a product. The prototype electronics and software for the vessel mounted equipment comprise a base unit which supports a minimum of four man over board detectors. Raycomm worked closely with a plastic design company to ensure optimum electronic placement within the equipment housings. The electronics design incorporated the following main features: 
Firmware was written for the base unit and the man over board detectors, in C and assembler respectively. C was written in C++ object oriented style to our own coding standard. Collectively, the software provides the following main features:
The vessel mounted equipment originally incorporated an Inmarsat D+ satellite transponder for sending position reports and alerts to the central server. After the prototype units had been developed, Iridium Satellite released a new Short Burst Data (SBD) modem which had lower running costs and could transmit significantly more data than the Inmarsat D+ service allowed. A decision was made to retrofit a number of base unit prototypes with the new Iridium SBD modem for trials. Two fishing vessels were equiped with the retrofitted base units and trialled over several months. The new Iridium modem was found to out perform the Inmarsat unit and proved to be significantly more reliable in operation.  A prototype base unit and set of man over board detectors were taken to a test house for pre-compliance testing against International standard EN60945 “Maritime navigation and radiocommunication equipment and systems – General requirements – Methods of testing and required test resultsâ€. The pre-compliance testing was performed in order to gain an insight to the performance of the electronics with regard to EMI compatibility. The base unit and man over board detectors were tested successfully for excessive radiated and conducted emissions. Prototype Base Units with PSD’s were fitted to a number of vessels and trialled over many months. In-house developed GPRS based monitoring units were used to remotely monitor the performance of the man overboard system so that any software or hardware problems could be identified. Regular detailed reports were generated for RNLI management based on the information received over the GPRS connection. The success of the prototype Base Unit and PSD’s led the RNLI to sign a partnership with McMurdo Ltd, giving them exclusive rights to manufacture, market and distribute the system. This necessitated taking the prototype electronics and software design through a productionisation phase, where the designs were optimised for production. PRODUCTIONISATION After the prototype had been proven, the next step was to take the design through a productionisation phase. This involved a number of tasks including cost reduction analysis, design for manufacture, enhancement of ergonomics and design for bed of nails testing. Our first task for productionisation involved performing a number of investigative studies on particular aspects of the system in order to make enhancements and improvements for production. The studies included investigations into battery technologies, processors, various schemes of Bluetooth operation and assessment of the capabilities of the Iridium satellite network with respect to the project requirements. These reports were used to verify a number of design decisions that were made early on in the project. The prototype PCB assembly was redesigned for production for optimum cost effectiveness. A number of aspects were revisited including the design of the power supply, power distribution, selection and rationalisation of components. Careful consideration to component selection was required in order to cater for the operational temperature range (-20ËšC to +60ËšC), in particular the choice of battery technology used in the base unit and man over board detectors. Battery charging activities was restricted to above zero Celsius ambient temperatures to prevent battery damage.  The electronics redesign for production included enhancing the battery life of the base unit. Should the fishing boat power supply to the base unit fail while the vessel is at sea, the base unit was required to run for at least a further 6 hours on battery operation. The base unit was also required to charge all four man over board detectors from the base units internal battery and enter a standby mode of operation when complete to avoid deep discharge of its internal battery. In order to achieve this and keep the base unit battery capacity to a reasonable size, a hardware standby mode of operation was designed which allowed various sections on the base unit to be powered down to conserve power. The prototype base unit program memory usage was near full capacity. The production software was planned to incorporate many more features so actions were required to extend the memory addressing capacity of the base unit processor. The most cost effective solution was found to be a new processor that had double the memory address space of the prototype design through the use of memory banking. Utilization of code banking caused various complications with the compiler and linker settings which were resolved. Areas of software were also redesigned in order to realize a more versatile product. The most significant area of change was formulating a scheme of Bluetooth operation that overcame many of the limitations of the standard Bluetooth pairing process. The efforts resulted in far greater flexibility and enhanced capabilities of operation when compared to conventional Bluetooth pairing.  One of the main new features of software development was the addition of geofencing capability. This means that the base unit constantly checks its distance from the fishing vessels mooring in order to configure on or off, the remote position reporting. When the fishing vessel is in the vicinity of its mooring, automatic position reporting is disabled. When the vessel is fishing at sea, the base unit enables sending of remote position reports to the server, i.e. the vessel is monitored. Many aspects of the man overboard safety system have been patented by the RNLI under World Intellectual Property Organization (WIPO) publication number WO/2007/028997. The patent covers many aspects of the system. Installation And Trials Raycomm assisted in the trials of the CPRS system. The RNLI devised a trials programme which required twenty fishing vessels to be fitted with the equipment and closely monitored. Raycomm deployed GPRS modems onto each trials vessel so that the software could be diagnosed efficiently in order to identify and eradicate bugs. The monitoring also allowed us to understand how the fishing vessel crew actually used the equipment in the field. 
An important aspect during the final stages of the project was to gain an understanding of what was involved to install the equipment on fishing vessels of differing construction and ages. A critical aspect of the system was to ensure that sufficient Bluetooth coverage was provided so that false man overboard alarms are not generated. The information and experience gained from assisting a number of installations were conveyed back to the RNLI for inclusion in the products documentation.
Technologies Involved
Raycomm are a UK based, custom software and electronics design and development service company creating bespoke electronic products, mobile device software applications, backend web server software and e-commerce database software. For a no-obligation discussion with one of our senior consultants on your project needs:
We look forward to hearing from you.
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