ROBOT

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄16

2016-09-24T10:08:00.001-07:00

10 وسائل تنقل مذهلة لم تسمع عنها من قبل

2016-09-18T12:10:00.001-07:00

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄15

2016-09-12T11:34:00.001-07:00

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄14

2016-09-07T11:13:00.001-07:00

Omnicharge Demo - Thank you Backers!

2016-09-02T14:12:00.001-07:00

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄13

2016-09-02T13:36:00.001-07:00

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄11

2016-08-20T12:48:00.001-07:00

4 Practical Part

2011-09-03T11:55:00.000-07:00

Figure 4.1 Crawler mechanical designs

4.1 Equations and analysis

The belt circumference needed in every stage of this design is variable when the planet wheels change its position as shown in figure 4.2 and 4.3, so when we need to choose the belt, we must calculate the belt length required at take care this point.

Figure 4.2 The main arm in horizontal position (minimum belt length required

Figure 4.3 The main arm in vertical position (maximum belt length required)

We choose the value of the radius of the driver wheels depending on the velocity Which we prefer to be less than (25 m/min), so we choose the speed of the motor to be 60 rpm (which is available) and the maximum velocity (25 m/min) then :

( RH : is the maximum driver wheel radius we need to have the maximum velocity )

So, we must choose RD less than (6.6314 cm) to have velocity less than 25m/min.

We choose RD = 6.25 cm .

The physical dimensions for mechanism used in experimental part of our project are shown in table 4.1 below:

Figure 4.4 Mechanical system parts

Table 4.1 Practical values for the mobile robot

Belt length can be calculated as follows:

The minimum belt length can be calculated from figure 4.2 as:

Minimum length (Lmin) = 2 [ BE + EF + FC ] (Eq-1)

The maximum belt length can be calculated from figure 4.3 as:

Maximum length (Lmax) = AC + CB + BE + EF + FA (Eq-2)

Where:

4.2 Calculations of the practical design

The calculations show that the length of the belt (circumference) required in the vertical position is longer than in the horizontal position.

Substituting physical values in equation 1, we obtain:

LMIN = 2 [45 + (50 - 22.5)] + (3.14 * 6.25) + (3.14 * 2.75)

= 173.274 cm

And substituting in equation 2, we obtain:

LMAX = 3.14 * 6.25 + 45 + 2 * [(22.5 + 6.25) + (50 + 2.75) ]

=184.787 cm

To solve this problem we choose the length of the belt depending on the horizontal position(L_MIN) and we put spring on the main arm to correct the increasing of the belt distance needed in the vertical position.

Figure 4.5 Spring position

Here we finished our project ( Tele - Operated Robot).

RESULTS AND RECOMNDATION

1-      We believe that crawler mobile robot design will allow us to solve many of the problems associated with obstacles such as stairs, roughness…etc.

2-      It's recommended in feature to continue and improve the software used in our project by using Image Processing or Voice Processing methods and improve the radio frequency link (RF transmitter and receiver ) by solve the noise problems and increasing the range .

3-      Despite the difficulties and obstacles faced in accomplishing our project, all the group members found this to be an important learning experience from a technical point of view and cooperated to solve the problems by arrangement the tasks.

3 PIC Microcontroller & Wireless Transfer

2011-09-03T10:39:00.000-07:00

3.6 Wireless Data Transfer

3.6.2 Transmitter (TX)

Figure 3.10 Transmitter IC

Table 3.5 Pin description for transmitter

Table 3.6 Technical Specifications for transmitter

3.6.3 ANTENNA

For 433 MHz frequency we have three type of antenna shown in Figure 3.11

Figure 3.11 The types of antenna

Next we will see the Practical Part...

3 PIC Microcontroller & Wireless Transfer

2011-08-28T08:08:00.000-07:00

3.6 Wireless Data Transfer

We transfer the control signals in our project using wires from PC to the PIC microcontroller.

To advance the project we use the radio frequency transmitter and receiver module for a wireless control transfer signals as another options.

The Compact FM Hybrid transmitter and receiver Modules are used in this project to receiving a signal data at up to 9.67kbps of the state of the transmitter with rang up to 250 m with CMOS/TTL Compatible Output, offers low current consumption , which uses no adjustable components ,and requires No radio license to operate . The transmitter is attached to the serial port on the PC to send data on the 433.92 MHz carrier to the motion control subsystem.

Figure 3.8 Radio frequency (RF) – Receiver and Transmitter

3.6.1 Receiver (RX)

Figure 3.9 Receiver IC (RX)

Table 3.2 Pin description for Receiver

Table 3.3 Operation mode for Receiver

Technical Specifications

Table 3.4 Technical Specifications for Receiver

3 PIC Microcontroller & Wireless Transfer

2011-08-28T07:49:00.000-07:00

3.5 Circuit Layout

Figure 3.6 PIC16F876 hardware interface connections

Figure 3.7 PIC16F876 hardware interface board

The previous figure shows the connection between the PIC microcontroller and the hardware components such as the stepper motors, D.C motors, light and so on. A crystal of 10MHz is connected to the CLKIN pin to generate the clock of the PIC. The data from the RF is received through the RA3 pin (pin5). Every one of the three D.C motors need three lines for direction and speed control(Enable,IN1,IN2) and the stepper motor needs two lines for direction control(Enable,(CW/CCW)). The output control lines of the microcontroller in this table shown below:

RB0	ENABLE (PWM)
RB1	IN 1	D.C motor 1
RB2	IN2
RB3	ENABLE (PWM)
RB4	IN1	D.C motor 2
RB5	IN2
RB6	ENABLE
RB7	IN1	D.C motor 3
RC0	IN2
RC1	ENABLE	Stepper
RC2	CW\CCW	motor

Table 3.1 Output control lines of the microcontroller

3 PIC Microcontroller & Wireless Transfer

2011-08-27T07:10:00.000-07:00

3.3 PC software

We used the visual basic 6 language to transmit the control signal to the serial port.

The visual basic program gives ability to control the robot by the user orders.

3.4 PIC programmer

PIC microcontroller is able to run programs written in assembly, PicC and PicBasic. You can purchase the programmer, but it is too expensive. In our project we design a new circuit as shown in figure 3.2 that is programming PIC 16F876 chip. The programmer don’t require a separate power supply, put takes the power from the serial port of a PC.

Connection with the PC is made by a cable 1-1, 9 pin connectors, male-female.

Figure 3.4 Programmers for PIC microcontroller

Programming the PIC microcontroller family can be done by changing the wires of this programmer to the same name pins of the other PIC new chip.

Figure 3.5 The programmer for PIC16f876

3 PIC Microcontroller & Wireless Transfer

2011-08-27T06:55:00.000-07:00

3.2 Serial port interface

The transmitting signal from PC ranges from 12 Volts to –12 Volts (RS level) which is not compatible with the PIC microcontroller or with the RF transmitter which required a voltage setting of +5 Volts to 0 Volts (TTL level), so we must put max232 as a level shifter between RS level and TTL level .

Figure 3.2 MAX232 IC connections

Figure 3.3 Connection between serial port in PC and MAX232 IC

3 PIC Microcontroller & Wireless Transfer

2011-08-27T06:29:00.000-07:00

3.1 PIC16F876 Microcontroller

The PIC16F876 is the “brains” of the Drive Subsystem. Using built-in RS232 interface, we were able to use two pins for transmitting (from user). We were able to check what inputs were coming in from the user and then decided which signals to send out to move the motors. By using the built-in Pulse width Modulating channels, we were able to control the speed of the two D.C motors at the same time. The remaining pins were general input and output pins and were used for outputs to control the stepper motor and D.C motors direction.

Figure 3.1 Pin Diagrams of PIC16F876

2.3 Power Supply

2011-08-27T05:52:00.000-07:00

In our project, 5 Volts was required for all the integrated circuits, 12 Volts was required For the D.C motors and 8Volts for stepper.

We use 5 Volts Regulator (LM 7805) to feed the integrated circuits, and 8 Volts regulator (LM7808) for the stepper motor.

2.3.1 LM78XX Regulator

The most common way of generating afixed voltage is to use the 78xx voltage regulator which has atypical tolerance of 5%.

Figure 2.12 LM78XX circuit diagram

2.2 Robot Drives

2011-08-27T05:42:00.000-07:00

2.2.4 Stepper Motor Drives

The stepper motors used in our design contain four input wires, one to each coil, plus a common voltage input. The stepping sequence of the motor can be controlled differently by assigning the input pulse on different combinations to the inputs A, B, C, and D indicated on figure 2.8 below.

Figure 2.8 stepper motor terminals

The possible stepping sequences are wave-drive, two-phase, and half-step. The wave-drive format activates one coil at a time in an A-B-C-D (or D-C-B-A, if reversing rotation direction sequence). The wave-drive mode consumes the least amount of power and has high positional accuracy.

Two-phase drive activates two adjacent coils during each sequence (AB-BC-CD-DA). This sequence mode offers an improved torque while decreases the rotation speed of the stepper motor.

Half-step activation alternates between the one-coil and two-coil modes (A-AB-B-BC-C-CD-D-DA), providing an eight-step sequence for smoother rotation.

2.2.4.1 UCN5804 Stepper Motor Driver

The stepper motors use a 9-12 Volts to support the movement of the camera. We use the integrated circuit stepper motor driver UCN5804B which can drive up to 50 volt 1.5 an output, and the inputs are compatible with TTL circuits. This driver provides four Darlington transistors at the output connecting to the stepper motor.

The following is the circuitry for each stepper motor with the UCN 5804 Integrated Circuit stepper motor driver.

Figure 2.9 UCN 5804 stepper motor driver

From the figure above, pin 9 and 10 determines the stepping sequence of the stepper motor. Since we decided to use two phase stepping sequence, and according to the truth table below, both pin 9 and 10 are at logic 0.

Table 2.2 Logic control for the stepper sequence

2.2.4.2 Circuit Connections

Figure 2.10 UCN5804 circuit connections

Figure 2.11 UCN5804 circuit and 555 IC board

As displayed in the figure 2.10 above, pin 9 and 10 are also used for ON/OFF switch of the stepper motor. This is because when both pin 9 and 10 are high, the step inhibit function is performed by the UCN5804 chip to stop the motor from running. Since our project only requires both pins to be low (half-step) or both high (step inhibit) at the same time, only one ON/OFF switch needs to be connected to both pins. The a, b, c, d pins in the figure are connections to the input pins of the stepper motor. Each input signals will control motor in the way described by the stepper motor section previously discussed. The diodes, LEDS, are put in so one can visually observe the stepping sequence and for debugging purposes. The direction (pin 14) is used to rotate the stepper motor clockwise or counterclockwise.

2.2 Robot Drives

2011-08-27T05:10:00.000-07:00

2.2.3 L6203 D.C motor driver

The IC is a full bridge driver for motor control applications realized in Multi power-BCD technology which combines isolated DMOS power transistors with CMOS and Bipolar circuits on the same chip.

By using mixed technology it has been possible to optimize the logic circuitry and the power stage to achieve the best possible performance. The DMOS output transistors can operate at supply voltages up to 42V and efficiently at high switching speeds. All the logic inputs are TTL, CMOS compatible. Each channel (half-bridge) of the device is controlled by a separate logic input, while a common enable controls both channels.

The integrated circuit L6203 is a full bridge driver for D.C motors; it can drive up to 48 volt with total RMS current up to 4 A outputs and has an operating frequency up to 100 KHz with high efficiency.

It is compatible with TTL logic circuit and has internal logic supply. This IC can optimize the logic circuitry and the power stage to achieve the best possible performance.

Figure 2.4 L6203 H-bridge

2.2.3.1 Pin connections for L6203

Figure 2.5 PIN connections for L6203

The logic drive shown in table:

Table 2.1 Logic control for l6203 IC

2.2.3.2 Circuit connections

Figure 2.6 L6203 circuit diagram

Figure 2.7 Driver board for L6203 and stepper motor

The transistors have an intrinsic diode between their source and drain that can operate as a fast freewheeling diode in switched mode applications.

2.2 Robot drives

2011-08-26T05:28:00.000-07:00

Figure 2.1: motors driver board

2.2.1 Introduction

To control the direction of D.C motor we need the H-bridge driver circuit using relays or transistors act like switches or integrated circuits like L298 or L6203.

In our project we use two D.C motors to provide the vehicle with four movement directions: forward and backward, rotate left and rotate right. The speed of the motors controlled by pulse width modulation (PWM). Also, One D.C motor used to move the main arm backward and forward.

For the stepper motor used to rotate the camera, we can use software from PC or microcontroller to produce the required sequence and an integrated circuit like UCN5804.

2.2.2 SPEED CONTROL

2.2.2.1 PWM

Pulse width modulation is a technique for reducing the amount of power delivered to a DC motor. This is typically used in mechanical systems that will not need to be operated at full power all of the time.

Instead of reducing the voltage operating the motor (which would reduce its power), the motor's power supply is rapidly switched on and off. The percentage of time that the power is on determines the percentage of full operating power that is accomplished and so reducing the speed.

Figure below illustrates this concept, showing pulse width modulation signals to operate a motor at 75%, 50%, and 25% of the full power potential.

Figure 2.2 Pulse width Modulation (PWM)

We produced the PWM signal in our project from the PIC microcontroller to control the speed of the vehicle.

2.2.2.2 Pulse Rate of stepper

The speed of the stepper motor is controlled by the width of the pulses that supplied to the integrated circuit (UCN5804B).

In our project we produced these pulses by (555) integrated circuit like shown in figure 2.2 below:

Figure 2.3 (555) pulser

Where:

R₁ = R₂ = 2 KΩ , C = 10 μF

Substituting these values to find period, duty cycle, t_on, and t_off we obtain:

Period = C [( R₁ + 2 R₂) ln(2)]

= 10 [(2 + ( 2*2)) ln(2)] = 0.04159 sec

duty cycle = ton / period = (R₁ + R₂ ) / ( R₁+ 2R₂)

= (2 + 2) / (2 + 4) = 0.6667 sec

ton = C ( R1 + R2) ln(2)

= 10 (4) * ln(2) = 0.02773 sec

t_off= C R2 ln(2)

= 10 * 2 * ln(2) = 0.01386 sec

Obviously, the smaller the step angle is, the more accurate the motor. But the number of pulses stepper motors can accept per second has an upper limit. Heavy duty steppers usually have a maximum pulse rate of 200 or 300 steps per second. Some smaller steppers can accept a thousand or more pulses per second, but they don't usually provide very much torque.

2 Robot Drives

2011-08-26T04:58:00.000-07:00

2.1.2 Motors Specifications

In our project the stepper motors provide the movement for the camera and three D.C motors for the movement of the vehicle. Stepper motors operate by producing motion in discrete steps and usually has permanent magnets on the rotor and coils on the stator. The changing magnetic field, due to the pulses supplied to different coils at different time, enables the motion of the rotor.

Motors come with extensive specifications. The meaning and purpose of some specifications obvious; below we written about the primary specifications of motors:

2.1.2.1 OPERATING VOLTAGE

All motors are rated by their operating voltage. Most motors can be operates satisfactorily at voltages lower than those specified, but it may not be as powerful as it could be, and it will run slower. Similarly, when it operates at voltage higher than those specified.

2.1.2.2 CURRENT DRAW

Current draw is more important when the specification describes motor loading. The current draw of a free running motor can be quite low .With most permanent magnet motors, current draw increases with load. If the system is designed to handle the stall current (short circuit current) it can handle anything.

2.1.2.3 SPEED

Most continuous DC motors have a normal operating speed of 4000 to 7000 rpm. However, some special purpose motors, such as those used in tape recording and computer disk drivers, operate a slow as 2000 to 3000 rpm. For just about all robotic applications, these speeds are much too high. This high speed is reduced to no more than 150 rpm by using a gear train. The speed of stepping motors is not rated in rpm but in steps (or pulses) per second. The speed of a stepper motor is a function of the number of steps that are required to make one full revolution plus the number of steps applied to the motor each second.

2.1.2.4 TORQUE

Torque is the force the motor exerts upon its load. The output torque and power from a stepper motor are functions of the motor size, motor heat sinking, working duty cycle, motor winding, and the type of driver used.

2.1.2.5 POWER

The power delivered by a motor is the product of its speed and the torque at which the speed is applied. The power of the stepper motor is a function of both the increased over-all pull-out torque and the increased stepping frequency range.

2.1.2.6 GEARS REDUCTION

The motor shaft is fitted with a gear of small radius that meshes with a gear of large radius. Depending on the mass of the robot and the performance desired, different gear ratios might be appropriate. Experimentation is probably the best way to choose the best gear train.

The DC motors that we use it in our design are already having a gear reduction box built onto the motor. When selecting gear motor, we interested in the output speed of the gearbox, not the actual running speed of the motor. Note as well that the running and stall torque of the motor will be greatly increased.

2 Robot Drives

2011-08-26T04:38:00.000-07:00

2.1 Introduction

How to move camera?

The camera rotates to view the status of environment in front of the robot which needs a high resolution of movement.

So we use the stepper motor to achieve this requirement.

How to drive and steer the robot?

The crawler type is drived and steered by two D.C motors. When the two D.C motors rotate at the same direction for example (CW), the robot will go forward. When the two D.C motors rotate at different directions (CCW), the robot will go backward. When the left D.C motor rotate in direction clockwise (CW) and the right one on counterclockwise direction (CCW), the robot will rotate to right. When the left D.C motor rotate (CCW) and the right one on (CW), the robot will rotate left.

2.1.1 Choosing the motors

At first step, we choose what type of motors to be used. Stepper motors are motors whose rotation can be controlled with a high precision. However, they require a pretty complex controller. DC motors are the most simple to control; it dominates the field of robot, either mobile or stationary.

D.C is used as the main power source for operating the onboard electronics, and for running the motors. Few robots use motors designed to operate from A.C, even those automations used in factories.

1.2 Mechanical system specification

2011-08-26T04:19:00.000-07:00

1.2.1 Principles of moving mechanism

There are three types of moving mechanisms; wheeled type, crawler type and legged type.

The wheeled type is the most common, but cannot overstep an obstacle larger than it's wheel diameter.

The legged type has stability difficulties and cannot be easily applied to high speed robots.

The crawler type can travel even on rough surfaces or slippery surfaces like snow and stairs with a good stability, and good speed. However, the conventional crawler type sometimes falls down when negotiating high steps on stairs or curbs. In the past, one proposed type had four crawler units, and by swinging each unit as was necessary to maintain position, it adapted to the road surfaces, the new variable shape crawler robots can move around easily without problems. Tracks turn by skidding or slipping with excellent traction, and they are best used on surfaces such as dirt that allow low-friction steering. Rubbers for the belt are common choice for medium crawler robot sizes; it's providing adequate grip for most kinds of surfaces.

Figure 1.2 The mechanical design

1.2.2 Crawler shape control

As shown in figure (1.3) below, driver wheels and free running wheels are mounted on both sides of the car body as part of the crawler unit supported with arms and composed of planet wheels with (Rp). By moving these planet wheels, we adapt driving to overstep the road obstacles.

Figure 1.3 Mechanical system parts

Crawler shape is altered by changing planet wheel position; the main arms which carry the planet wheels rotate around the center point between the driver wheels and free running wheels.

1.2.3 Robot body material

The main structure of our robot is made of aluminums. We choose aluminum in our design due to appearance, low weight, low cost, resistance to corrosion, availability, and so on. Onto the frame of the robot mounted motors, batteries, electronic circuit board, and other necessary components.

1.1 A Tele - Operated Robot

2011-08-25T15:38:00.000-07:00

A tele-operated robot is one that is commanded by a human and operated by remote control. The typical tele-operated robot uses a video camera that serves as the eyes for the human operator. From some distance-perhaps as near as a few meters to as distance as several million meters the operator views the scene of interest and command the robot accordingly. Figure (1.1) shows the system component and relation between the system parts:

Figure 1.1 – block diagram show the communication between the robot and the PC.

This mobile robot can be used in security, in exploration and in other applications, to transmit picture from unstructured environment. Can be changed the work properties of his robot depending on environment that the robot will be working in. Also, a manipulator can be mounted on robot base for executing special purpose which is difficult to be done by human being.

Introduction

2011-08-25T15:12:00.000-07:00

when we decided to make our graduated project,we thout in this way:

Since 1980, the robot has established itself in manufacturing. Now new demands for robots are spreading to other industrial fields like the construction, transportation, medical, military, and other fields.

The purpose of our project was to design a mobile robot that can overcome the terrain roughness, climb, stairs, run over trenches, … etc.

A crawler moving design was choosed for this purpose.

The movement of our robot is controlled by three D.C motors, the movement of camera is controlled by a stepper motor, and the overall system is controlled by the PIC microcontroller. RF link was used for the wireless communication between the robot and the PC. Depending on the command sent to the robot from PC, either the robot moves, or the camera moves. Image is transmitted back to the TV adapter card of a PC through the video sender unit of the wireless camera.

Our mobile robot equipped with camera mounted on top to transmit an image of environment in front of the robot.

This image will be received on a PC using wireless communication. An image is required to provide the required information about the environment to the operator controlling the robot movement.

Our Robot is called A Tele - Operated Robot.

ROBOT

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄16

10 وسائل تنقل مذهلة لم تسمع عنها من قبل

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄15

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄14

Omnicharge Demo - Thank you Backers!

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄13

ﺍﺧﺘﺮﺍﻋﺎﺕ ﻣﺪﻫﺸﺔ ﻟﻢ ﺗﺴﻤﻊ ﻋﻨﻬﺎ ﻣﻦ ﻗﺒﻞ ◄◄11

4 Practical Part

The belt circumference needed in every stage of this design is variable when the planet wheels change its position as shown in figure 4.2 and 4.3, so when we need to choose the belt, we must calculate the belt length required at take care this point.

4.2 Calculations of the practical design

The calculations show that the length of the belt (circumference) required in the vertical position is longer than in the horizontal position. Substituting physical values in equation 1, we obtain: LMIN = 2 [45 + (50 - 22.5)] + (3.14 * 6.25) + (3.14 * 2.75) = 173.274 cm

And substituting in equation 2, we obtain:

LMAX = 3.14 * 6.25 + 45 + 2 * [(22.5 + 6.25) + (50 + 2.75) ]

=184.787 cm

To solve this problem we choose the length of the belt depending on the horizontal position(LMIN) and we put spring on the main arm to correct the increasing of the belt distance needed in the vertical position.

Figure 4.5 Spring position

Here we finished our project ( Tele - Operated Robot).

RESULTS AND RECOMNDATION

3 PIC Microcontroller & Wireless Transfer

3 PIC Microcontroller & Wireless Transfer

3 PIC Microcontroller & Wireless Transfer

3 PIC Microcontroller & Wireless Transfer

3 PIC Microcontroller & Wireless Transfer

3 PIC Microcontroller & Wireless Transfer

2.3 Power Supply

2.2 Robot Drives

2.2 Robot Drives

2.2 Robot drives

2 Robot Drives

2 Robot Drives

1.2 Mechanical system specification

1.2.2 Crawler shape control

As shown in figure (1.3) below, driver wheels and free running wheels are mounted on both sides of the car body as part of the crawler unit supported with arms and composed of planet wheels with (Rp). By moving these planet wheels, we adapt driving to overstep the road obstacles.

Figure 1.3 Mechanical system parts

Crawler shape is altered by changing planet wheel position; the main arms which carry the planet wheels rotate around the center point between the driver wheels and free running wheels. 1.2.3 Robot body material

The main structure of our robot is made of aluminums. We choose aluminum in our design due to appearance, low weight, low cost, resistance to corrosion, availability, and so on. Onto the frame of the robot mounted motors, batteries, electronic circuit board, and other necessary components.

1.1 A Tele - Operated Robot

Introduction

The calculations show that the length of the belt (circumference) required in the vertical position is longer than in the horizontal position.

Substituting physical values in equation 1, we obtain:

LMIN = 2 [45 + (50 - 22.5)] + (3.14 * 6.25) + (3.14 * 2.75)

= 173.274 cm

To solve this problem we choose the length of the belt depending on the horizontal position(L_MIN) and we put spring on the main arm to correct the increasing of the belt distance needed in the vertical position.

Crawler shape is altered by changing planet wheel position; the main arms which carry the planet wheels rotate around the center point between the driver wheels and free running wheels.

1.2.3 Robot body material