Gesture Controlled Car

Transcription

1 Gesture Controlled Car Chirag Gupta Department of ECE ITM University Nitin Garg Department of ECE ITM University ABSTRACT Gesture Controlled Car is a robot which can be controlled by simple human gestures. The user just needs to wear a gesture device in which a sensor is included. The sensor will record the movement of hand in a specific direction which will result in the motion of the robot in the respective directions. The robot and the Gesture instrument are connected wirelessly through radio waves. User can interact with the robot in a more friendly way due to the wireless communication. We can control the car using accelerometer sensors connected to a hand glove. The sensors are intended to replace the remote control that is generally used to run the car. It will allow user to control the forward, backward, leftward and rightward movements, while using the same accelerometer sensor to control the throttle of the car. Movement of car is controlled by the differential mechanism. The mechanism involves the rotation of both forth & rear wheels of left or right side to move in the anticlockwise direction and the other pair to rotate in the clockwise direction which makes the car to rotate about its own axis without any kind of forward or backward motion. The main advantage of this mechanism is the car with this mechanism can take sharp turn without any difficulty. Keywords Arduino- ATMEGA 8A, Accelerometer ADXL335, IC- L29DNE, RF Module. INTRODUCTION The robot is usually an electro-mechanical machine that can perform tasks automatically. Some robots require some degree of guidance, which may be done using a remote control or with a computer interface. Robots can be autonomous, semi-autonomous or remotely controlled. Robots have evolved so much and are capable of mimicking humans that they seem to have a mind of their own. An important aspect of a successful robotic system is the Human-Machine interaction. In the early years the only way to communicate with a robot was to program which required extensive hard work. With the development in science and robotics, gesture based recognition came into life. Gestures originate from any bodily motion or state but commonly originate from the face or hand. Gesture recognition can be considered as a way for computer to understand human body language. This has minimized the need for text interfaces and GUIs (Graphical User Interface). Gesture recognition technologies are much younger in the world of today. At this time there is much active research in the field and little in the way of publicly available implementations. Several approaches have been developed for sensing gestures and controlling robots. Glove based technique is a well-known means of recognizing hand gestures. It utilizes a sensor attached to a glove that directly measures hand movements. 59

2 A Gesture Controlled robot is a kind of robot which can be controlled by hand gestures and not the old fashioned way by using buttons. The user just needs to wear a small transmitting device on his hand which includes a sensor which is an accelerometer in our case. Movement of the hand in a specific direction will transmit a command to the robot which will then move in a specific direction. The transmitting device includes a Comparator IC for assigning proper levels to the input voltages from the accelerometer and an Encoder IC which is used to encode the four bit data and then it will be transmitted by an RF Transmitter module. At the receiving end an RF Receiver module will receive the encoded data and decode it by using a decoder IC. This data is then processed by a microcontroller and passed onto a motor driver to rotate the motors in a special configuration to make the robot move in the same direction as that of the hand. WORKING PRINCIPLE Gesture controlled robot works on the principle of accelerometer which records hand movements and sends that data to the comparator which assigns proper voltage levels to the recorded movements. That information is then transferred to an encoder which makes it ready for RF transmission. On the receiving end, the information is received wirelessly via RF, decoded and then passed onto the microcontroller which takes various decisions based on the received information. These decisions are passed to the motor driver IC which triggers the motors in different configurations to make the robot move in a specific direction. The following block diagram helps to understand the working of the robot: Fig.1. Block diagram Task was divided into two parts to make the task easy and simple and to avoid complexity and make it error free. The first is the transmitting section which includes the following components: Accelerometer, encoder IC, RF Transmitter Module. The second is the receiving end which comprises of following main components: RF Receiver Module, Decoder IC, Microcontroller, Motor Driver IC, DC Motors. The accelerometer records the hand movements in the X and Y directions only and outputs constant analog voltage levels. These voltages are fed to the microcontroller which processes the input and encodes the data into digital form which is suitable to be transmitted through the xbee serial transmitter. Fig.2. Input and Output of microcontroller The conversion of analog to digital waveform takes place through a continuous pulse train generator attached to the microcontroller. The RF transmitter modulates the input signal using Amplitude Shift Keying (ASK) 60

3 modulation.. It is the form of modulation that represents digital data as variations in the amplitude of a carrier wave. The following figure shows the modulated output of the RF module: 61 Fig.3. ASK Modulation EXPERIMENTAL DETAILS Following were the major components used in designing of the gesture controlled car. 1. Microcontroller(arduino- atmega 8a 2. RF module(xbee wireless modulexbee series 1 with protocol 3. Free scale 2 axis accelerometeradxl Batteries (9v ) 5. DC motors 256 rpm 6. IC- l293dne, ht12d ic, ht12e ic 7. Chasis wooden Transmitting and Receiving circuits Fig.4. Transmitting circuit Fig.5. Receiving circuit This transmitted signal is received by the RF receiver, demodulated and then passed onto the decoder IC. The decoder IC decodes the coded waveform and the original data bits are recovered. The input is a serial coded modulated waveform while the output is parallel. The pin 17 of the decoder IC is the Valid Transmission (VT) pin. A led can be connected to this pin which will indicate the status of the transmission. In the case of a successful transmission, the led will blink. The parallel data from the encoder is fed to the port 1of the microcontroller. This data is in the form of bits. The microcontroller reads these bits and takes decisions on the basis of these bits. What the microcontroller does is, it compares the input bits with the coded bits which are burnt into the program memory of the microcontroller and outputs on the basis of these bits. Port 2 of the microcontroller is used as the output port. Output bits from this port are forwarded to the motor driver IC which drives the motors in a special configuration based on the hand movements. SIMULATION Simulation of project is performed on PROTEUS and the code was written in C++ language using KEIL MICROVISION. Code

4 for the microcontroller to run DC motors using the H-Bridge IC (L293D) is written. In the simulation the relevant data to the Microcontroller (ATMEGA8A) is send through switches. The Microcontroller processed the data and sent the information to the Actuator IC (L293D). The Actuator IC upon receiving information showed response by driving the DC motors. The simulation schematic is as follow: When switches A and D are on, motor rotates clockwise. When B and C are on, the motor rotates anti-clockwise. When A and B are on, the motor will stop. Turning off all the switches gives the motor a free wheel drive. Turning on A & C at the same time or B & D at the same time shorts the entire circuit. So, never try to do it. Fig,6. Simulation on KEIL MICROVISION RESULT 62 Fig.7 H Bridge Fig.8. Gesture controlled car CONCLUSION The purpose of project is to control a toy car using accelerometer sensors attached to a hand glove. The sensors are intended to replace the remote control that is generally used to run the car. It will allow us to control the forward and backward, and left and right movements, while using the same accelerometer sensor to control the throttle of the car.

5 camera which will broadcast and a receiver module which will provide live streaming. REFERENCES [1] Nitin and Naresh, Gesture Controlled Robot PPT, URL Available [ [2] Naveet Kumar, Neeraj Purohit, Gesture Controlled Tank Toy User Guide URL Available [ Accessed 13 October [3] Jochen Triesch and Christoph Von Der Malsburg Robotic Gesture Recognition (1997) URL Available [ ] Accessed 15 October [4] Real-Time Robotic Hand Control Using Hand Gestures by Jagdish Lal Raheja, Radhey Shyam, G. Arun Rajsekhar and P. Bhanu Prasad. [5] Bhosale Prasad S., Bunage Yogesh B. and Shinde Swapnil V. Hand Gesture Controlled Robot URL Available Fig.9. Hand gesture control Future Scope -board batteries occupy a lot of space and are also quite heavy. We can either use some alternate power source for the batteries or replace the current DC Motors with ones which require less power. transmission, the range is quite limited; nearly 50-80m. This problem can be solved by utilizing a GSM module for wireless transmission. The GSM infrastructure is installed almost all over the world. GSM will not only provide wireless connectivity but also quite a large range. -board camera can be installed for monitoring the robot from faraway places. All we need is a wireless [6] [ meter-based-hand-gesture-controlled-robot] Accessed 3 November, [7] [ r_1.html] Accessed 5 November, [8] [ Accessed 5 November, [9] [ Accessed 6 November, [10] [ Time-Robotic-Hand-Control-Using-Hand-Gestures] Accessed 6 November, [11] [ Accessed 8 November, [12] [ hat-is-back-emf-counter-electromotive-force] Accessed 8 November, 2013 [13] [ Accessed 9 November, 2013 [14] [ [15] [ 63