Energy Management System

O Energy Management System (EMS) � um sistema integrado de manuten��o de energia de baterias com interface com um PC, constru�do em torno de um microcontrolador AVR ATMega8 e sensores de corrente LEM. Surgiu como um projecto extracurricular sugerido pelo Professor Nuno Alexandre Cruz associado ao Grupo de Sistemas Oceanogr�ficos com o intuito de ser utilizado no Zarco ASV e mais tarde ser adaptado a outros ve�culos. Possui dois objectivos prim�rios:

Ser um sistema de alarmes, capaz de detectar valores de correntes anormais (com os limites inferior e superior configur�veis a partir de uma qualquer m�quina equipada com porta s�rie) e lan�ar avisos � m�quina a que est� ligado (no caso do Zarco ASV, o computador de bordo).

Gerir a carga de baterias, no que se inclui o c�lculo da pot�ncia instant�nea a ser consumida, estimativas de carga restante na bateria e da energia gasta, e lan�amento de alarmes em caso de carga demasiado baixa.

Em conjunto com o sistema foi desenvolvido um protocolo de comunica��o que opera sobre comunica��o USART, podendo o EMS ser configurado a partir de qualquer m�quina equipada com uma porta RS232 e um programa de terminal. � poss�vel activar/desactivar alarmes e sensores, redefinir limites superior e inferiores de corrente para cada sensor (que v�o despoletar os alarmes), reconfigurar sensores de corrente, redefinir a carga das baterias, e pedir valores actuais de corrente e tens�o.

The Energy Management System (EMS) is an embedded system designed to manage energy in batteries. It interfaces with a PC and is built around the AVR ATMega8 microcontroller and LEM current transducers. It was created as an extracurricular project suggested by Professor Nuno Alexandre Cruz for the Ocean Systems Group with the goal of being used in the Zarco ASV and later being adapted to other vehicles.The system serves two main purposes:

To be an alarm system capable of detecting abnormal current values (its upper and lower limits configurable through any machine equipped with a serial RS232 port) and to send out warnings to the machine to which it's plugged to (in the present case, the onboard computer on the Zarco ASV).

To manage charge in batteries, which includes the calculation of instant power, estimation of remaining charge and spent energy, and the sending of alarms in case of dangerously low charge values).

In parallel with this system a communication protocol was developed that operates on the USART link, which enables EMS to be configurable from any machine equipped with a RS232 port and a terminal program. It's possible to activate/deactivate alarms and current sensors, define the upper and lower current limits for each transducer (those that trigger the alarms), reconfigure the current parameters of each current transducer, redefine the charge in each battery, and check current values for both voltage and current.