The proposed display system has a great reliability and stability in addition to it’s given function in an Electric vehicle. To transmit a message signal in practical conditions under poor environment is difficult, so reliability and stability are most important factors. This system mainly concentrates on the design of hardware of the display system for the pure electric vehicle and the interface system designing is also done taking the features of embedded systems. This can be made used to design significant interface circuits such as data acquisition and control signal interface, power supply module, speed odometer interface, engine speed interface, oil instructions interface, water temperature interface, car battery charger power connector and other important nodes in the vehicle interface circuit. From the actual measurement results, the hardware indicators of the LCD instrument display system fully meet the basic requirements of the design.
For years in automotive field, mechanical parts of the moving coil type or magnetomotive machines were used. But it had too many restrictions and hence increased complexity cause of too many performance indexes needed to be taken care of. Nowadays most of these mechanical systems are being replaced by electrical parts and they provide better performance and efficiency. Digital instruments that are multifunctional are used for improved precision. Here an attempt is done in the direction of development and implementation of a semi-autonomous electric vehicle to increase the efficiency of the vehicle-user interface. This has been built upon the base of ARM where we use ADC to convert the received data from analog signal to digital signal and this is fed to the LCD display.
The functions are been done by CAN protocol and it helps in the designing of both hardware and software of the expected system. Here in the hardware we are using ARM7 mainly, CAN communication controller, along with LPC2129 and design schematic circuit diagram relating CAN bus system hardware. Software functions are dealing with the setting up of data transmission between different nodes and thus the transmission of data from node to node. Software Module mainly consists of the following components such as CAN initialization unit, message sending and receiving units and the interrupt service unit.
Controller Area Network is a fast serial data bus whose sole function is to enable reliablility, efficiency and a very advanced communication between sensors and actuators. Twisted-pair cables are being used in Controller area networks to set up communication between two nodes and the data rate it provides is nearly 1 Mbits/sec and is able to connect upto 40 devices at once. At first CAN was only designed to solve the issues regarding the wiring in automobiles. Traditionally point to point wiring systems were used in automobiles for data transfer but as the technology developed electronics found it’s place in the system of data transfer and controllers are introduced for monitoring and controlling several functions. And this definitely made the wiring more complex, heavy, expensive and bulky.
In a sensor network, there are mainly three components that play an important role and they are sensor node module, computer server module and computer client module.
An 8 bit AVR processor had been built in the processor along with CAN I/O controller, an SPI digitizes the signals recieved from temperature sensors. All these sensor nodes are connected with each other to a two-wire physical CAN bus (CAN H and CAN L), and this is being controlled by a central PC . CAN was built by Robert Bosch (in 1986). It was invented as a reply to the quest of Mercedes for a data transmission system between 3 electronic control units(ECU) in vehicles. Point to point communication was not acceptable no longer, and the multi-master system was required to step in. Industrial automation need to be developed causing the requirement of such bus systems to come into play. CAN is a two wire, half duplex, high-speed network system,it has a throughput up to 1 Mbits/sec. transmitted. The transfer layer delivers data about the Kernel of CAN protocol. It is in charge of presenting and recieving the received/transmitted messages to/from the upper layer.
It contains Power supply, LCD display,ARM7 processor and the actuators. The duty of the crystal is generate clock frequency and an RC network that comes along a switch would be used for resenting the microcontroller and for power on reset .The LCD used is 16 X 2 for the Display. The output from ARM7TDMI processor is displayed on LCD .
The LPC2129 is a 16/32 bit , ARM7 Processor. It has real-time impersonation and embedded trace support. LPC2129 also has 128/256 kBs of a very huge speed flash memory. There is a 128-bit broad internal memory interface and an accelerator architecture helps in execution of 32-bit code.This occurs at maximal clock rate. 16-bit Thumb Mode decreases code by greater than 30% with fewer performance fine when critical code applications comes into play. It has a compact structure,i.e 64 and 144 pin packages, consumes lesser power, varieties of 32-bit timers, 4 channel 10-bit ADC and 2/4 CAN channels or 8- channel 10-bit ADC and 2/4 CAN channels (64 and 144 pin packages respectively).It also has up to 9 external interrupt pins.
The LM35 is a temperature sensor, i.e an integrated circuit. It can be made use for measuring temperature. LM35 gives an output which is electrical in nature and obeys a proportionality to the temperature (in °C). It gives the value of temperature more precise when compared to a thermistor. The circuit of the sensor is been closedand it can’t be undergone oxidation. The LM35 gives out a huge output voltage in comparison to thermocouples and wouldn’t need that the output voltage be strengthened. The scale factor is given as 0.01V/°C. The LM35 wouldn’t need an external calibration or modification and it keeps an accuracy of +/-0.4°C at room temperature and +/- 0.8° ranges from a range of 0°C to +100°C. One of the other main property of LM35 is that it recieves only 60 micro amps from its source and have a low self-heating capability. The sensor has a sensitivity of 10mV / °C.
Considering the data possessed in the data signals, the dominion software installed inside the vehicle, in advance displays the engine speed and real time fuel utilization in the expected forms and in proper units. There is a possibility that by making use of data from the CAN-Bus works on a huge varieties of parameters. For instance, at time of field tests of agriculture tractor. Application of CAN-Bus during pulling of tractor tests under field conditions defined also Super et al. (2012). A problem that might happen by making use the data from CAN-Bus is the accurate data that was scanned. After evaluating the of accuracy of fuel utilization and data acquired from CAN-Bus of agriculture tractor dealt study by the authors Polarity al. (2013) or Sedlák et al (2011). Outputs of these studies displays that in particular engine modes engine Electronic control units can find inaccurate data of real time fuel consumption.
A better solution has been provided to design and develop the intelligent vehicle which will keep an eye on the varieties of input data in the vehicle in-between fixed time slots and will deliver the signals to the base unit. By using hardware base whose Core is ARM7 and CAN. The proposed system could put an end to the function of communicating with the base station via CAN. The whole Control system has the added pros of fewer volume and huge reliability. Future scope of this is to data without collision.
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