ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
Design & Implementation of Automotive
Intelligent Node CAN bus in Hybrid Electric
Vehicles using ARM7
Mani kanth Alapati, Dr .N.S.Murthi Sarma, V.Anuragh, CH.V.S.Subrahmanyam
Abstract
In this paper, a design of controller area network (CAN) bus
technology is proposed in hybrid electric vehicles (HEV). This
new technology primary objective is to build hardware that
interface and communicate directly with CAN network and
extract CAN messages for reliable car communications. The
hardware is a circuit board that is capable of capturing CAN
signals released from an automobile. The CAN node hardware
configuration has two options, one is a MCU which interior is
integrated of a CAN controller and the transceiver, another
option is that a general MCU, a separated CAN controller and the
transceiver. The design consists of four major hardware modules:
single chip microcontroller, three hardware modules, CAN
controller and CAN transceiver. Microcontroller software is
developed to perform six major functions: controller
initialization, service interrupt generation, switch, display, CAN
communication and power conversion. The relative simplicity of
the CAN protocol means that very little cost and effort need to
expended on personal training; the CAN chips interfaces make
applications programming relatively simple. One of the
outstanding features of the CAN protocol is its high transmission
reliability. This proposed work finds implementation by using
ARM based embedded system designs methodology, which
includes embedded hardware and firmware design modules. This
is one of most out standard feature of the CAN protocol in its high
transmission reliability.
Index terms: CAN Controller, CAN transceiver, hybrid electric
vehicle, ARM 7
I. INTRODUCTION
Hybrid electric vehicles two energy sub systems to offer the
power .The battery sub system can offer the motor system
electrical energy to drive the motor and at the same time the
engine sub system can also propel the wheels to go
forward.HEV is more complicated traditional vehicles; it
includes control unit, vehicle management unit, battery
management unit, power management unit etc. The control
units are complicated in control; they must independently
transmit a lot of data
MANIKANTH ALAPATI: PG scholar, Department of Electronics
and Communication Engineering/ BVC engineering college/odalrevu/
Odelarev/ India/ phone no: 9705480770.
Dr .N.S.MURTHI SARMA: Professor & HOD/ Department of
Electronics and Communication Engineering/ BVC engineering college/
odalrevu/India,phone no:9701631125.
V.ANURAG: Asst.Professor/ Department of Electronics and
Communication Engineering/ BVC engineering college/, odalrevu/ India
CH.V.S.SUBRAHMANYAM: Asst.Professor/ Department of
Electronics
and
Communication
Engineering/BVC
engineering
college/odalrevu/ India.
In traditional electrical vehicle communication system
includes RS-485 communication system. As a result of the
serial communication system, this has some disadvantage of
principal and sub ordinate structure, the time sub section
communication and low communication efficiency, the
assembly efficiency of the control units is low. High
performance electrical vehicle depends on all the electrical
units on electrical vehicles running in phase based on certain
advanced central strategy, In order to realize the strategy, the
intelligent control system of data communication could be
necessity. Controller area network is a type of communication
network. It has lot of advantages. The CAN bus technology has
become a popular communication way in more vehicles. Each
electronic control unit in the automotive control network based
on CAN bus can be regarded as an intelligent node, in which
ID address, bitrates, work mode, etc. are set through
programming.
In this paper, the hardware rationale and the control
software of the intelligent node were elaborated in details. The
CAN node hardware configuration has two options, one is a
MCU which interior is integrated of a CAN controller and the
transceiver, another option is that a general MCU, a separated
CAN controller and the transceiver. The CAN controller
peripheral requires minimal external hardware, using only a
bus driver chip, containing the power devices to drive the
network, and the receiver hardware to read data off it. CAN
has been successfully applied to gas line automotive
applications before, but rarely to electric vehicles.
The CAN control system is developed to integrate and
control most 12V dc auxiliary loads and power supplies with in
ECU. The main objectives are to demonstrate the operation,
access the overall performance, and identify particular benefits
which might accurate when using the CAN control
systems.CAN has been successfully applied to gas line
automotive applications before, but rarely to electric vehicles.
This paper has 8 sections with introduction &
conclusion. Part II of this paper describes scope of the work,
part III describes literature survey, part IV describes
methodology of work, part V introduces CAN bus in HEV,
part VI introduces CAN bus communication protocols in HEV,
Part VII describes hardware design.
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All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
II. SCOPE OF THE WORK
IV .METHODOLOGY OF WORK
The tremendous growth of research and technology in
the fields of embedded systems, CAN bus surveillance systems
demand the fulfillment of hybrid electric vehicles.
Electromagnetic compatibility has been the primary standard
for safe usage of hybrid electric vehicles. The CAN bus plays a
major role in improving the system performance. The CAN
controller system should satisfy the HEV standards without
degrading the system performance. Thus, it is ultimately a
trade-off between embedded systems and their location for
optimizing the performance and environmental effects. To
investigate the effects of CAN layer protocols on interfacing
circuits within the structure; several essential parameters are to
be considered. Prominent among them are CAN node analysis
and reliability.
In addition to this, an effective data transformation to
different systems in frames is to be considered. The present
analysis will help to evaluate the performance of controlling
system in a complex embedded environment. An embedded
model for building blockage in hybrid electric vehicle
communication system can be developed using our analysis.
This model characterizes the data transmission from
microcontroller when there is calibration in the nodes of
hardware modules. While, using CAN, both controller and
transceiver from the structures should be considered. This
information will be useful in developing reliable
communication in Hybrid electric vehicles. Thus, our analysis
is also useful for modeling the CAN bus in presence of LPC
2148 controller in embedded environment.
With the growing electronics industry, modern
vehicles are becoming more and more complex, and the need
for integrating subsystems together is becoming more
important than ever before. To accommodate different
system‟s needs and requirements, manufacturers have
developed new vehicle networking protocols, such as CAN,
LIN and MOST, which are currently being used jointly in
vehicles. To demonstrate the ability of integrating different
control systems together in a vehicle, the CAN (Controller
Area Network) control system is implemented to control and
integrate selected 12Vdc auxiliary loads within the MR2. Since
the CAN control system is designed to control power flow to
auxiliary loads, the existing power distribution network used
within the vehicle has to be understood. For this reason, the
power distribution network used within the vehicle to supply
power to all parts of the vehicle, including the CAN control
system.
III. LITERATURE SURVEY
This research proposes the design of a novel control
strategy that improves data transformation speed between ECU
of electric vehicle by using an add-on package which includes
CAN transceiver, CAN controller and LPC 2148. It is title
“add-on” because of its compact structure and simplicity to
implement on existing non hybrid electric vehicles. This aspect
has led to take up the present investigation. Initially electromechanical system was established in HEV, But CAN bus
communication protocol so far established reliability and speed
between the major units in HEV. Yu Zhilong and Li
Dongsheng have combined part to predict complete simulation
pattern for hybrid electric vehicles using CAN bus [1].
Hongxing and kuo use CAN bus technology attain realize
communication and data sharing between electrical units on
HEV. Also they reported that anti-jamming ability has been
carried out according to interface level requirement [2].
Abdel Azeeh and Richard Duke have combined part
of CAN control system on hybrid electric vehicles. They attain
partial results realated to discuission [7]. H.Hung attain the
analysis of the speed of data transmission in hybrid electric
vehicles[8].However, the approach in this thesis is different
from approaches used by previous authors. A novel technique
based on CAN bus technology is developed in this paper. This
can be useful to obtain automotive intelligent node CAN bus
for reliable data transferring in electrical units of a hybrid
electric vehicle system. This idea suggests that if an external an
external thermocouple devices, proximity sensors and micro
controllers added to prototype standalone package, the control
strategy will only determine the data transformation according
to CAN protocol in HEV. So, data in frames transformation
between CAN L and CAN H are important from the driver
pedal; unlike typical HEV.
Figure 1.Syetem flowchart for LPC 2148
An analysis of embedded systems such as CAN bus
design in HEV can be performed efficiently by reproducing the
structures with appropriate models, which are in simple
structures. Those structure that control the data transfer can be
done in terms of frames, by using all protocols of the CAN bus.
The returns of the CAN bus can be found solutions to
approximate data transfer problems. For example international
all HEV system includes RS-485 communication system [3].
As a result of serial communication, this has some
disadvantages such as principal sub ordinate system,
inefficiency of speed and reliability of data between the control
units is low. As shown in Fig.1 by using CAN bus protocols
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All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
and data transfer frame theory, inefficiency of communication
and reliability are carried out. This analysis is validated by
comparing the results with published results. As shown in
Fig.2 CAN H, CAN L buses, CAN controller, CAN transceiver
modules and microcontroller LPC 2148 reliability and speed
are developed.
SAE traffic network committee classified the data
transmission net-work into three kinds including A type, B
type and C type for convenient study, design and application,
design and application [4]. A type turns towards Low Speed
Network controlled by sensors or actuators. The bit rate of data
transmission usually is only 1~10kb/s. They are mainly used to
control the electric windows, seat adjust and lamplight
illumination [5]. B type turns toward the moderate speed
network of data sharing between independent modules. The bit
rate usually is 10~100kb/s. They are mainly used in systems
such as information centre of electronic vehicle, fault
diagnosis, instrument display and air bag to reduce redundant
sensors and other electronic units. C type turns toward the
multipath trans-mission with high speed and real-time closedloop control. The highest bit rate is 1Mb/s. Fig. 3 shows that
the CAN bus should be utilized in due course i.e., serial
communication which helps us to transfer the data from
microcontroller LPC 2148 to CAN controller 82C250 [6].
VI.CAN BUS COMMUNICATION PROTOCAL IN HYBRID
ELECTRIC VEHICLES
As shown in fig.4 in Hybrid electric vehicles CAN
communication system, nodes must have the CAN bud
interfaces that are composed of CAN controller and CAN
transceiver, The CAN controller of systematic nodes include
on the following way [9].
Interface management logic. It can receive the command from
CPU and offer CPU an interrupt and state signal.
Transmit buffer. It is used to save the message from CPU need
to be transmitted to CAN bus.
Figure 2. System flow chart for CAN bus.
Receive buffer. When CPU is handling the frame of message,
the controller can still receive the next frame.
V. CAN BUS IN HYBRID ELECTRIC VEHICLES
CAN bus which belongs to the category of field bus is a kind
of serial communication network which supports distributed
control or real-time control effectively. Currently, many
existing auto network standards have different emphasis about
their functions.
Receive filter. It can receive the filter logic and compare the
data frame mark with the content in receive filter to determine
whether the content in receive filter to determine whether the
message is concerned with the node. If unconcerned, the
message will not be transmitted to enter receive buffer, which
can lighten the burden of CPU.
Bit stream processor .It can control transmit buffer and receive
the data operations such as data exchange, error detection,
arbitration, fill and management etc. between FIFO and data
stream on CAN bus.
Bit time logic. It can make controller synchronous with bit
stream in CAN bus.
Error management logic. It can define what is wrong according
to CAN protocol [7].
Figure 3. CAN bus module
The CAN communication protocol is a carrier-sense
multiple-access protocol with collision detection and
arbitration on message priority. CAN protocol include CAN
layers and CAN messages frames. The first version of the
CAN protocol, Standard CAN 2.0A, is for applications up to
125 kbps with a standard 11-bit identifier. The version of CAN
2.0B extends to a 29-bit identifier. The CAN module for the
M16C29 microcomputer is a communication controller
implemented with a CAN 2.0B protocol [10].
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All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
The CAN module consisting of components: C Tx/C
Rx, protocol controller, message box, acceptance filter, 16-bit
timer, wake-up function, and interrupt generation function
[11].The C Tx and C Rx are interface pins for the external
CAN bus driver and receiver. The protocol controller handles
the bus arbitration and services, i.e. bit timing, stuffing, error
status etc. The message box consists of 16 slots that can be
configured either as transmitter or receiver and each slot
contains an individual identifier, data length code, a data field
(8 bytes) and a time stamp. The acceptance filter performs
filtering operation for received messages. The 16-bit timer is
used for the time stamp function.
A.
CAN Layers
The CAN is divided into different layers to achieve
design transparency and implementation flexibility. CAN 2.0A
is made up of four layers: application, object, transfer, and
physical layer. CAN 2.0B have application, data link and
physical layers. Fig .5 which shows that CAN 2.0 protocol
layers for A and B. The application layer generates or
interprets data and actually sends and receives messages. The
object layer is responsible for handling messages, such as
selecting a transmitted or received message, working as an
interface between the transfer layer and the application
program running on the CPU. The transfer layer ensures that
messages adhere to the protocol.
Cyclical Redundancy Check (CRC), Acknowledge (ACK), and
end of frame. The start field is made up of a single dominant
bit which is used by receiving nodes to synchronize the receipt
of a data frame. The arbitration field contains the identifier
number of a message [12]. The identifier number is used by
receiving nodes to determine the acceptance or rejection of a
particular data frame. The identifier contains either 11 bits or
29 bits for standard and extended format respectively. The
arbitration field also contains a Remote Transmission Request
(RTR) bit that is used to distinguish a data frame from a remote
frame. The control field contains four bits that specify the data
length in bytes. The data length is specified by four separate
bits, allowing data lengths from one to eight bytes. The data
field contains the actual transfer message. For each byte, the
most significant bit is transmitted first.
The CRC field is used to test the validity of the data
received. The CRC ends with a CRC delimiter bit. The ACK
field contains an ACK slot and an ACK delimiter.
Figure 5. CAN 2.0 protocol layers
The ACK slot is used by a receiving node to inform
the transmitter that a message (data frame) has been accepted
correctly by sending one dominant bit within the ACK slot.
The ACK delimiter bit is a single recessive bit. The last field at
the end of frame field consist of seven receive bits [13].
Figure 4.CAN bus communication protocol in HEV
The physical layer defines the physical (hardware)
implementation and the electrical
(signal level)
implementation of the bus, network cabling, connector type,
pin-out, physical
data rates, maximum transmission
distances, and data transmission encoding. In CAN 2.0, the
data link layer transmits frames over the network. Different
network and protocol characteristics are defined by different
data link layer specifications [12].
B. CAN message Frames
In a CAN system, data is transmitted and received
using message frames. Message frames carry data from a
transmitting node to one, or more receiving nodes. Four
different message frames exist on CAN network bus: data
frame, remote frame, error frame, and overload frame. Data
frame contains seven sub fields: start, arbitration, control, data,
Figure 6.Schematic diagram
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All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
VII.HARDWARE DESIGN
Fig.6 which shows the developed platform which uses
single chip microcontroller ARM LPC 2148 and MCU, three
module boards, CAN controller, CAN transceiver , power
supply module Logic input complementary CMOS quad driver,
International Rectifier power MOSFET logic level gate driver,
and communicates through a CAN bus [14].
A. ARM LPC 2148 Microcontroller
The ARM7TDMI-S is a general purpose 32-bit
microprocessor, which offers high performance and very low
power consumption. The ARM architecture is based on
Reduced Instruction Set Computer (RISC) principles, and the
instruction set and related decode mechanism are much simpler
than those of micro programmed Complex Instruction Set
Computers. This simplicity results in a high instruction
throughput and impressive real-time interrupt response from a
small and cost-effective processor core. Pipeline techniques are
employed so that all parts of the processing and memory
systems can operate continuously. Typically, while one
instruction is being executed, its successor is being decoded,
and a third instruction is being fetched from memory. The
ARM7TDMI-S processor also employs a unique architectural
strategy known as Thumb, which makes it ideally suited to
high-volume applications with memory restrictions, or
applications where code density is an issue. The key idea
behind Thumb is that of a super-reduced instruction set.
ARM7TDMI-S processor has two instruction sets
a) The standard 32-bit ARM set.
b) A 16-bit Thumb set.
The Thumb set‟s 16-bit instruction length allows it to
approach twice the density of standard ARM code while
retaining most of the ARM‟s performance advantage over a
traditional 16-bit processor using 16-bit registers. This is
possible because Thumb code operates on the same 32-bit
register set as ARM code. Thumb code is able to provide up to
65 % of the code size of ARM, and 160 % of the performance
of an equivalent ARM processor connected to a 16-bit memory
system.
programmed In System via the serial port. The application
program may also erase and/or program the Flash while the
application is running, allowing a great degree of flexibility for
data storage field firmware upgrades, etc. When on-chip boot
loader is used, 120/248 KB of Flash memory is available for
user code. The LPC2148/LPC2129 Flash memory provides a
minimum of 100,000 erase/write cycles and 20 years of data
retention. On-chip boot loader (as of revision 1.60) provides
Code Read Protection (CRP) for the LPC2148/LPC2129 onchip Flash memory. When the CRP is enabled, the JTAG
debug port and ISP commands accessing either the on-chip
RAM or Flash memory are disabled. However, the ISP Flash
Erase command can be executed at any time (no matter
whether the CRP is on or off). Removal of CRP is achieved by
erasure of full on-chip user Flash. With the CRP off, full
access to the chip via the JTAG and/or ISP is restored.
On-Chip static RAM may be used for code and/or
data storage. The SRAM may be accessed as 8-bits, 16-bits,
and 32-bits. The LPC2119/LPC2129 provides 16 KB of static
RAM. Fig. 7, which indicate that interfacing of CAN bus to
microcontroller that gives structural view of the CAN bus
protocol communication [15].
B. CAN Controller (82C250)
The PCA82C250 is the interface between the CAN
protocol controller and the physical bus. The device provides
differential transmit capability to the bus and differential
receive capability to the CAN controller. The PCA82C250 is
the interface between the CAN protocol controller and the
physical bus. It is primarily intended for high-speed
applications (up to 1 M baud) in cars. The device provides
differential transmit capability to the bus and differential
receive capability to the CAN controller. As shown in Fig. 8 it
is fully compatible with the “ISO/DIS 11898” standard.
Figure 7. Micro controller interfacing to CAN bus
The LPC2148 incorporates a 128 KB and 256 KB
Flash memory system respectively. This memory may be used
for both code and data storage. Programming of the Flash
memory may be accomplished in several ways. It may be
Figure 8. Internal Block diagram of 82C250
A current limiting circuit protects the transmitter
output stage against short-circuit to positive and negative
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All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
battery voltage. Although the power dissipation is increased
during this fault condition, this feature will prevent destruction
of the transmitter output stage [15]. If the junction temperature
exceeds a value of approximately 160 °C, the limiting current
of both transmitter outputs is decreased. Because the
transmitter is responsible for the major part of the power
dissipation, this will result in reduced power dissipation and
hence a lower chip temperature. All other parts of the IC will
remain in operation. The thermal protection is particularly
needed when a bus line is short-circuited. The CAN H and
CAN L lines are also protected against electrical transients
which may occur in an auto motive environment. Pin 8 allows
three different modes of operation to be selected: high-speed,
slope control or standby. For high-speed operation, the
transmitter output transistors are simply switched on and off as
fast as possible. In this mode, no measures are taken to limit
the rise and fall slope. Use of a shielded cable is recommended
to avoid RFI problems. The high-speed modem is selected by
connecting pin 8 to ground.
For lower speeds or shorter bus length, an unshielded
twisted pair or a parallel pair of wires can be used for the bus.
To reduce RFI, the rise and fall slope should be limited. The
rise and fall slope can be programmed with a resistor
connected from pin 8 to ground. The slope is proportional to
the current output at pin 8 [16]. If a HIGH level is applied to
pin 8, the circuit enters a low current standby mode. In this
mode, the transmitter is switched off and the receiver is
switched to a low current. If dominant bits are detected
(differential bus voltage >0.9 V), RxD will be switched to a
LOW level. The microcontroller should react to this condition
by switching the transceiver back to normal operation (via pin
8). Because the receiver is slow in standby mode, the first
message will be lost.It is best with features of high speed (up
to 1 Mbaud), bus lines protected against transients in an
automotive environment slope control to reduce radio
frequency interference (RFI), differential receiver with wide
common-mode range for
high immunity against
electromagnetic interference (EMI), thermally protected, shortcircuit proof to battery and ground low-current standby mode,
an unpowered node does not disturb the bus lines and at least
110 nodes can be connected.
transients that CAN occur on the bus lines. The inclusion of an
internal pull-up resistor on the transmitter input ensures a
defined output during power up and protocol controller reset.
For normal operation at 500 baud the ASC terminal is open or
tied to GND. For slower speed operation at 125 baud the bus
output transition times CAN be increased to reduce EMI by
connecting the ASC terminal to VCC. The receiver includes an
integrated Filter that suppresses the signal into pulses less than
30 ns wide [16]. Fig. 6 shows, CAN bus interfacing circuit.
The CAN controller and CAN transceiver are internal modules
of CAN bus communication unit [17].
Figure 9.CAN interfacing circuit
D. Speed Odometer Circuit
C. CAN Transceiver (MCP 2551)
As shown in Fig.9 CAN transceiver is an interface
between protocol controller and the physical bus. The
MCP2551 is a high-speed CAN transceiver, fault-tolerant
device that serves as the interface between a CAN protocol
controller and the physical bus. The MCP2551 provides
differential transmit and receive capability for the CAN
protocol controller and is fully compatible with the ISO-11898
standard, including 24V requirements. It will operate at speeds
of up to 1 Mb/s typically; each node in a CAN system must
have a device to convert the digital signals generated by a
CAN controller to signals suitable for transmission over the
bus cabling (differential output). It also provides a buffer
between the CAN controller and the high-voltage spikes that
can be generated on the CAN bus by outside sources (EMI,
ESD, electrical transients, etc.).The device provides transmit
capability to the differential bus and differential receive
capability to the controller.
The transmitter outputs (CANH and CANL), feature
internal transition regulation to provide controlled symmetry
resulting in low EMI emissions. Both transmitter outputs are
fully protected against battery short circuits and electrical
In speed odometer circuit proximity sensors are used,
these proximity sensors are interchangeable with existing
sensors of similar characteristics or can be designed
specifically for individual application needs. These non contact
sensors are available with single pole double throw switches
(Form C), or Form A and B. They offer a variety of ways to
sense the relative position of specific machine elements
requiring continuous monitoring. Several different fabrication
materials can be used. Materials are selected based on the
application environment. The standard operating temperature
range is from -40°C to 125°C (-40° to 257°F) [13].
Sensors can be ordered in sets containing the sensor,
the actuator and hardware, or the components can be ordered
separately. These cost-effective sensors are offered in standard
designs and engineered designs with various actuation points.
Inductive proximity sensors are widely used in various
applications to detect metal devices. They can be used in
various environments (industry, workshop, lift shaft...) and
need high reliability. Inductive proximity sensors generate an
electromagnetic field and detect the eddy current losses
induced when the metal target enters the field
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All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
. The field is generated by a coil, wrapped round a
ferrite core, which is used by a transistorized circuit to produce
oscillations. The target, while entering the electromagnetic
field produced by the coil, will decrease the oscillations due to
eddy currents developed in the target. If the target approaches
the sensor within the so-called "sensing range", the oscillations
cannot be produced anymore: the detector circuit generates
then an output signal controlling a relay or a switch.
E.
Level Measuring Circuit
Float is the one type of transducer which is
used to measure the water level in the tank. The float changes
the resistance value depending on the water level. As shown in
Fig. 9 change in resistance is converted into corresponding
voltage signal which is given to inverting input terminal of the
comparator. The reference voltage is given to non inverting
input terminal. The comparator is constructed by the
operational amplifier LM 741 [11].
The comparator compares with reference water level
and delivered the error voltage at the output terminal. Then the
error voltage is given to next stage of gain amplifier which is
constructed by another operational amplifier LM 741. In the
gain amplifier the variable resistor is connected in the feedback
path, by adjusting the resistor we can get the desired gain.
Then the final voltage is given to ADC for convert the analog
signal to digital signal. Then the corresponding digital signal is
given to microcontroller in order to find the water level in the
tank [16].
F. Temperature Sensors
The coolant temperature sensor is used to measure the
temperature of the engine coolant of an internal combustion
engine. The readings from this sensor are then fed back to
the Engine control unit (ECU).
data may also be used to provide readings for a coolant
temperature gauge on the dash. The coolant temperature sensor
works using resistance. As temperature subjected to the sensor
increases the internal resistance changes. Depending on the
type of sensor the resistance will either increase or decrease.
There are two common types of coolant temperature
sensors in use on automotive engines. Negative Temperature
coefficient (NTC) and Positive temperature coefficient (PTC).
The difference between the two is when the sensor is exposed
to heat. In the case of Negative temperature coefficient sensor
the internal Electrical resistance will decrease as it is exposed
to more heat, whilst the opposite is true in a Positive
temperature coefficient sensor. Most Automotive coolant
temperature sensors are NTC sensors [18].
The ECU sends out a regulated reference voltage
typically 5 volts to the Coolant Temperature Sensor, through
the sensor where the voltage is decreased in relation to the
internal resistance within the sensor which varies with
temperature. This voltage is then returned to the ECU via the
signal wire. The ECU is then able to calculate the temperature
of the engine, and then with inputs from other engine sensors
uses lookup tables to carry out adjustments to the engine
actuators.
VIII. RESULTS & DISCUISSION
The experimental results obtained fulfills with the
requirements of the system. The objective of the
implementation is the data transformation using CAN bus in
HEV. The data transferring of the system works well, without
errors. This system guarantees data transfer rate 10-100 kbps.
Each measurement satisfies the requirements of a monitoring
system. The LCD shows temperature of radiator, speed of the
CAR, fuel level in digital form .The existing system developed
with RS-485, consist of principal sub ordinate system. In this
case, the solutions are obtaining with high speed operation of
CAN bus with ARM7. In order to test and verify the
functionalities of the developed project, the system was
deployed. Several aspects of the system were tested, but due to
space constraint, only a couple of these tests will be the subject
of discussion in this section. A video of the whole test process
was also taken, of which several screenshots from this video
are provided here.
In order to control and manage the electronic gadgets
with the predefined modes, then sequence of instructions to be
loaded into the microcontrollers. As shown in Fig. 10 flash
magic tool will be used to configure the embedded hardware
modules. The LPC2148 microcontroller is supported by
various commercially available IDEs for compiling and
debugging of the code. Keil being one of them is the widely
used IDE for LPC family of microcontrollers.
Figure 9.Level measuring using circuit
This data from the sensor is then used to adjust
the fuel injection and ignition timing. On some vehicles the
sensor may be used to switch on the electronic cooling fan. The
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All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
application code is developed in C programming language.
Figure 11. Hardware prototype
Figure 10. Flash magic configuration tool
The μVision4 IDE is Windows-based software development
platforms that combines a robust editor, project manager, and
make facility. μVision4 integrates all tools including the C
compiler, macro assembler, linker/locator, and HEX file
generator. The evaluation version of Keil μVision4 IDE is used
for this project. After the completion of developing the code
Flash magic is used to dump the code into the microcontroller
kit.
The Fig. 10 shows some experimental results obtained
with the LCD screen inside the vehicle. Once activated, the
screen displays the three values: temperature of radiator, speed
and fuel level of tank in digital. The figure shows the screen
related with CAN bus. This screen gives the information of the
instantaneous values of required one after a define period of
time. The refresh speed of the measures satisfies the
requirements of a monitoring system. The driver can see each
five second the behavior of each battery, but this speed is not
enough if a control system is required. In this case, the
solutions are operating with a higher speed in the One Wire
bus and use a faster microcontroller. In this analysis, the
IX.CONCLUSION
The CAN bus technology has become a popular
communication way in more vehicles. Each electronic control
unit in the automotive control network based on CAN bus can
be regarded as an intelligent node, in which ID address,
bitrates, work mode, etc. are set through programming. This
design consists of four major hardware modules: single chip
microcontroller, three hardware modules, CAN controller and
CAN transceiver. The CAN controller system should satisfy
the HEV standards without degrading the system performance.
An analysis of embedded systems such as CAN bus design in
The Kiel IDE software will be used to build the hex
file for these C programs. Overall hardware structure was
designed, three modules with LPC2418 interfacing was design.
By using CAN controller 82C250, CAN transceiver MCP 2550
controlling of data between proximity sensors, float level
sensors, thermo couplers and CAN H, CAN L was done.
Consideration of protocols of CAN layers embedded C code
was implemented. Initially theory was evaluated by analyzing
the characteristics CAN bus and LPC 2148 controller, by using
ARM Kiel IDE software Hex file was built for the hardware.
As shown in Fig. 11 proximity sensors, thermo couplers, float
level sensors are interface through CAN controller (82C250)
and CAN transceiver (MCP 2551) to ARM 7 (LPC 2148)
microcontroller. This hardware module was implemented in
such a way to extract it for future also.
Figure 12.CAN bus interfacing circuit
HEV can be performed efficiently by reproducing the
structures with appropriate models, which are in simple
structures. CAN bus which belongs to the category of field bus
is a kind of serial communication network which supports
distributed control or real-time control effectively.
The CAN communication protocol is a carrier-sense multipleaccess protocol with collision detection and arbitration on
message priority. The experimental results obtained fulfills
with the requirements of the system. The objective of the
implementation is the data transformation using CAN bus in
HEV.
28
All Rights Reserved © 2012 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 1, Issue 5, November 2012
The CAN topology is selected for communicating
around the electric vehicle since the CAN protocol is
optimized for systems that need to transmit and receive a
relatively small amount of information reliably to any or all
other nodes on the network. Since the protocol is messagebased, all nodes on the bus receive every message, regardless
of whether the node required the data or not. Fast robust
message transmission with fault confinement is the big plus for
CAN because faulty nodes will automatically drop off the bus,
which does not allow any faulty node to bring down the
network. Various CAN implementation methods were
discussed and the stand-alone CAN controller configuration
was chosen. This is because with this configuration, multiple
designs could be developed in the future and the software and
hardware development is reusable. The CAN control system
was designed and consists of five CAN nodes. Prototype of
these boards are developed and constructed successfully.
A multi-node CAN bus is designed based on CAN
2.0B. The structure of HEV control system is introduced.
According to the requirement of control system, a CAN
topology is developed. The methods of hardware and software
design of CAN bus are discussed. Based on the 32-bit
MC68376, power isolation and optoelectronic isolation are
applied in the hardware design of CAN communication circuit.
The design methods of software algorithmic are emphasized.
Buffer sharing and time sharing are applied in the program
design of CAN bus. The idea of multi-task is introduced. Task
assignment and scheduler could optimize the real time of CAN
communication, by event interrupt. Road rate of multi-node
CAN bus is analyzed. In order to calibrate the ECU, the CCP
driver is designed, which can achieve the data upload and
download for calibration.
The prototype of the CAN control system was
constructed and tested successfully. To verify the correct
operation of the CAN control system, the overall time delay of
the message transmission via the CAN bus was found to be fast
enough for the MR2 application, with the driver not noticing
the delay. Finally, the overall system was tested and all the
loads that are used to simulate the selected auxiliary loads in
the MR2 were operated and controlled successfully. It is
expected that a fully working CAN control system would
fulfill the requirements of the electric vehicle and operate
successfully in the MR2.
Various CAN implementation methods were
discussed and the stand-alone CAN controller configuration
was chosen. This is because with this configuration, multiple
designs could be developed in the future and the software and
hardware development is reusable. The CAN control system
was designed and consists of five CAN nodes. Prototypes of
these boards are developed and constructed successfully. The
prototype of the CAN control system was constructed and
tested successfully. To verify the correct operation of the CAN
control system, the overall time delay of the message
transmission via the CAN bus was found to be fast enough for
the MR2 application, with the driver not noticing the delay.
Automatic speed control unit also will be interfaced to this
circuit .It control the speed of the car by using disk breaking
system. This system will be connected as one of the node point
to the CAN bus.
APPENDIX
CAN: CONTROLLER AREA NET WORK is a network
which has speed of data rate with1Mb/s. It acts as a high
reliable bus. It is used for control in industrial and automotive
applications. CAN is open standard with many variants.
ECU: ELECTRICAL CONTROLING UNIT is unit has
controlling of all electronic modules, such as microcontroller,
CAN controller and CAN transceiver are major parts. It should
control all hardware modules of the project.
CCP: CAN COMMUNICATION PROTOCAL, the CAN
communication protocol is a CSMA/CD protocol. The CSMA
stands for Carrier Sense multiple Accesses. What this means is
that every node on the network must monitor the bus for a
period of no activity before trying to send a message on the
bus. Also, once this period of no activity occurs, every node on
the bus has an equal opportunity to transmit a message
(Multiple Access). The CD stands for Collision Detection. If
two nodes on the network start transmitting at the same time,
the nodes will detect the „collision‟ and take the appropriate
action.
HEV: HYBRID ELECTRIC VEHICLE is a vehicle that uses
an internal combustion engine and an electric motor as
propulsion systems to increase the system efficiency. These
vehicles are the short term solution to the reduction in the
demand for fossil fuels.
ARM: ADVANCED RISC MACHINE, i.e. advanced reduced
instruction set computer machine which acts advanced
microcontroller and microprocessor. It consists of
microprocessor, memory, I/O devices and Analog to digital,
digital to analog converters.
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