Difference between revisions of "LIFT"
| Line 6: | Line 6: | ||
[[File:ElevatorModel.jpg|400px|thumb|right|alt=Alt text|Fig. 1: Schematic of physical model]] | [[File:ElevatorModel.jpg|400px|thumb|right|alt=Alt text|Fig. 1: Schematic of physical model]] | ||
| + | |||
| + | [[File:IMG_3144.JPG|300px|thumb|right|alt=Alt text|Fig. 2: Stepper motor setup in lego model]] | ||
=Controller circuit= | =Controller circuit= | ||
==first prototype== | ==first prototype== | ||
| − | In the first verion of control board, a XULA fpga board has been used. Pin configuration of this board has been shown in Fig. | + | In the first verion of control board, a XULA fpga board has been used. Pin configuration of this board has been shown in Fig. 3. |
| − | [[File:Schematic.png|400px|thumb|right|alt=Alt text|Fig. | + | [[File:Schematic.png|400px|thumb|right|alt=Alt text|Fig. 3: Schematic of control board]] |
The first prototype control board provides the following functionalities: | The first prototype control board provides the following functionalities: | ||
| Line 54: | Line 56: | ||
===Sensor System=== | ===Sensor System=== | ||
| − | + | [[File:IMG_3145.JPG|300px|thumb|right|alt=Alt text|Fig. 4: Sensor setup on the lego structure]] | |
===Safty Monitoring System=== | ===Safty Monitoring System=== | ||
Since this model is designed to be controled remotely, it should be able to maintain its functionality even if it is programmed with a faulty design. For this reason we need some monitoring system to guarantee | Since this model is designed to be controled remotely, it should be able to maintain its functionality even if it is programmed with a faulty design. For this reason we need some monitoring system to guarantee | ||
| Line 69: | Line 71: | ||
A lab report template has been provided for students. | A lab report template has been provided for students. | ||
| − | = Remote Lab = | + | =Testing= |
| + | == Simuation == | ||
| + | A VHDL testbench has been designed to be used for verifying the functionality of the lift. | ||
| + | == Remote Lab == | ||
in this project, a remote lab was designed for students to access the controlling hardware from any remote place inside the department INTERA network. | in this project, a remote lab was designed for students to access the controlling hardware from any remote place inside the department INTERA network. | ||
The server is running on a raspberry pi and students can see a view of the working lift using an internet camera. | The server is running on a raspberry pi and students can see a view of the working lift using an internet camera. | ||
Revision as of 15:11, 3 December 2014
Lift Project is one of the projects designed in department of computer engineering at TTU as a lab project.
Physical Model
Lego Construction
A lego model has been built for this lab. you can see the schematic of the model in Fig. 1.
Controller circuit
first prototype
In the first verion of control board, a XULA fpga board has been used. Pin configuration of this board has been shown in Fig. 3.
The first prototype control board provides the following functionalities:
- Seven segment display
- Inner and outer cabin push buttons
- Motor state indicator LEDs
- software reset button
Signal Names and Description
The first prototype board has the following signals:
| Name | Port | type |
|---|---|---|
| clk | in | STD_LOGIC |
| sensors | in | STD_LOGIC_VECTOR (4 DOWNTO 0) |
| calls | in | STD_LOGIC_VECTOR (4 DOWNTO 0) |
| menu | in | STD_LOGIC_VECTOR (4 DOWNTO 0) |
| motor | out | STD_LOGIC_VECTOR (1 DOWNTO 0) |
| sleep | out | STD_LOGIC |
| Seven segment | out | STD_LOGIC_VECTOR (6 DOWNTO 0) |
Description
- Sensors should be designed according to the following functionality:
- Sensors are prone to bouncing because of vibrations in the lift which might not be visible to the naked eye but is visible to the sensors. Hence the sensors need to be de-bounced by a three bit shift register with 19th bit of counter slowing the de-bouncing circuit.
- The lift has five ray cut Infra-Red (IR) sensors.
- When ever a sensors ray is cut by the lift it sends a signal '1' to the FPGA. Otherwise the sensor sends a '0'
- Each sensor is placed between floors and there can be blind spots between each sensor. When the lift is in a blind spot all sensors send "00000" to the FPGA. This is the time when the lift is moving between two sensors. At this point sensors can also recieve value from two sensors as well. (e.g. on the second floor sensors can either have a value "00000" or "00110".) It is recommended that both cases should be handled by the designer. (hint: rather then looking for sensor ="00100" look for sensor(2)= "1".)
- Motor Signals
- Motor(0) controls the direction of the motor. Where '1' is DOWN '0' is up
- Motor(1) generates a clock signal which controls the speed of the motor. The speed is specified by a clk like signal by changing its frequency. The recommended speed of Motor can be given by sending 10th bit of the counter.
- A sleep signal turns off the motor. In idle state the motor should be kept turned off. where '1' is ON and '0' is OFF
- Motor FSM should also shares its Status with Floor FSM ( i.e. idle, going up, going down, blinking Seven segment)
- Seven segment should work as follows
- Seven segment decoder decodes the current floor into seven segment output.
- Each segment is turned on by logic value 1. Seven segment should also be able to blink 5 times after it reaches a floor.
- Seven segment the pin orientation (i-e. seven segment <= "abcdefg";)
Sensor System
Safty Monitoring System
Since this model is designed to be controled remotely, it should be able to maintain its functionality even if it is programmed with a faulty design. For this reason we need some monitoring system to guarantee the functionality.
hardware break
A physical switch has been installed on the top floor to prevent faulty designs to go through the roof.
behaviour monitor
Since reaching hardware break will require human intervention and it would not always possible (in times that an operator is not present etc.), a behavior monitor system has been added to the lift. Motor control signals goes through the monitoring system and if it detects a suspicious behaviour (being on first floor and unwinding the thread or being on the top floor and trying to move up) it takes over the control and brings the lift to the initial position and sends a reset signal to the control board.
Lab Reports
A lab report template has been provided for students.
Testing
Simuation
A VHDL testbench has been designed to be used for verifying the functionality of the lift.
Remote Lab
in this project, a remote lab was designed for students to access the controlling hardware from any remote place inside the department INTERA network. The server is running on a raspberry pi and students can see a view of the working lift using an internet camera. A working sample of the controller is provided to the students as a demo in order to get them accustomed to the functionality of the Lift. you can access this lab from this link: cherry.pld.ttu.ee
Web Server
- server on Raspberry Pi
- username and password for restrictions on access
- internet webcam
Push button emulator
- using Raspberry Pi GPIO for emulating push button behaviour
Future Work
- queueing system for login in remote lab
- checking the bitfile for malicious code
- making a 3D model for printing
- providing access for students outside ATI interanet
- PCB design for control board
- adding a micro-controller based control board
- monitoring all the sensors in monitoring system
.
