Corporate Personnel Movement: An Application of GPS and GIS
On Board Hardware Device This essentially offers the specially made electronic unit (Fig-2) achieving a set of specific tasks, which go a long way to enable the overall system functioning. The GPS DSP chip which offers, with the help of an active antenna or with in-built LNA, provides on the serial port continuous (up to 4 Hz frequency) and moderately accurate position data and importantly, accurate GMT time. Modern chips have ingenious methods to tackle congested city level hazards of position measurement like urban canyons and dead reckoning issues. It is felt that in certain applications like the present one, at least wheel tick measurement externally for consistent distance measurement enhances the reliability of the system substantially. The brain of such an embedded system will always be the MCU with non-volatile memory, which not only ensures coordination between various sub-systems but also manages the memory for periodic data storage, execute all control tasks and communicate with the external MMI unit (Fig-3) as well as serve the wireless messaging requirements.  “Figure 2: Electronic unit” A modern unit should perform a large number of control tasks on line like proximity based event alerts, speed monitoring and alerts, stationary data rejection etc. However, with the fairly reliable GPRS connectivity being available, most of these control tasks are performed at Server end thus reducing the burden of the firmware based tasks. The most reliable power supply system with full rechargeable battery based backup system as well as watch dog programs for ensuring graceful shut down and power-up operations and system resets are a must. The other most important component of this mobile hardware unit is the wireless communication interface, which can be a GSM modem chip. There has to be facility to interface intelligently the GSM modem with the MCU so that all four channels of GSM communications can be simultaneously available and any can be activated quickly depending on requirement. The circuit-switched channels like voice, SMS and Data are all switched on as and when required. Voice is activated when either an external call is coming or when a distress button is pressed initiating a call from the unit. A useful feature here is a local auto-hunting facility, where the distress call automatically gets escalated to higher-level numbers if lower level lines are busy. The Data channel is mainly meant for remote interrogation to evacuate stored data and over-the-air hardware programming. The SMS channels in conventional units are used for immediate machine-readable message generation to alert the control center computer or the operator and also for instantaneous polling of data. The only packet switched channel on GPRS actually can, in normal circumstances, make all the alternative data channels redundant by sending compressed data packets at programmable frequency to control center computer enabling not only on-line polling but also the full high frequency data base updates and generation of any amount of supervisory alerts. However, the value of the other point-to-point dedicated circuit switched channels become important in case of data or link loss, which is not such a rare occurrence. Additional monitoring inputs in the hardware device can be fuel gauge (analog), air-conditioner status, door ajar signal etc and remote controlled features like immobilizer, Buzzer operation, broadcast messaging etc. Bi-directional voice communication is normally enabled through hands-free unit or loudspeaker-microphone unit as per customer practice or preference. Portable MMI unit For corporate personnel movement industry, it has been found that an intelligent MMI unit (Fig-3), suitably portable and convenient to use with simple data input facility is very important. With this in view a hand held unit is designed, having its’ own micro-controller, autonomous program to address the various work flow sequences and data input keys like hard events (pick, drop, no show, trip start and end, duty break etc.) and numeric keys for soft inputs like employee id etc. are provided.  “Figure 3: MMI unit” The in-built display facilitates not only input prompts but also used for journey status display, call info and alerts display as well as system diagnostics for quick servicing at field conditions. Application Software and Services  “Figure 4: Flow Chart – CPM” The system of corporate personnel movement solution has essentially three parts to it (Fig-4)
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