An najah national university Faculty of engineering Electrical engineering department General Educational robot Student :- Mohammad auni nofal. Supervisor :- Dr.Samer Mayaleh May

Introduction It is a general educational robot which can do complex movement with 13 degree of free dome. And applicable for many applications such as Islamic praying and as a police on a certain junction with four directions an supported by three languages which is Arabic, English and Spanish.

Why this project Robots are complex system and it spreads around the word nowadays put doesn’t exist in Palestine. Robotics needs good background in several electrical Engineering Topics. I am interested in this subject.

I want through my project to break the barrier of fear from robotics technology. robotics need knowledge in electrical, mechanical and computer engineering

The tasks and abilities of this Robot:- It will be able to perform some complex movement like praying “Islamic praying”, to be an educational tool. Another application may be as a police man on 4 direction junction in stead of a human police man or a traffic light

The mechanical structure allow him to walk and it will be improved in the future to be a discovery robot in addition to praying.

The mechanical structure Its structure made from plastic (ocolone) 7 degrees of freedom, Joints. gearboxes, stripes, pointed …etc It will take a human being shape as shown

The electrical structure and controllers 1. 8 DC motors and 5 stepper motors fixed on the joints of the robots 2. Control circuit consists of a TX and a Rx to control the robot wirelessly,”IR remote control”. 3. voice recorder IC [ISD25120P ] to record the suitable voice and display it to match with the movement.

4. Two microcontrollers [pic-16F877] to control and drive the different parts of the robot. 5. Other peripherals like H-bridges to interface the DC motors, speakers, logic gates, Darlington pairs, etc....

Motors functions details Multidir- ectional Maximum angle Rotational direction RepetitionMotor type The joint Unidir.180 ºL,R1Stepper1 Unidir.90º,90ºU,D2DC2 Bidir.90º,90ºL,R&U,D2Stepper3 Unidir.0º, 0ºstatic2Non4 Unidir.90º,90ºFW,BW2DC5 Unidir.90º,90ºFW,BW2DC6 Unidir.90º,90ºFW,BW2DC7

DC motor drive circuit

How to control 8 DC motors using two pic only To control a DC motor direction, speed and position we need two ccp’s and each pic provide two only, but using the following pic-c function solve the proble for(int8 i=0;i<150;i++) { (pulse_fM1(8); restart_wdt(); }

pulse_fM1(int x) { output_high(PIN_A2); delay_ms(x); output_low(PIN_A2); delay_ms(10-x); }

Stepper motor drive circuit

Minimization number of pin to drive 5 steppers To control 5 stepper motors 4 control word for each need 20 pin’s, which inapplicable in the case of two pic design So; I used decoding to control and minimize 20pin’s to 12 pin’s only decoder solve the problem.

The sequence needed to control and drive the stepper motor for one step is as following:- Terminal one: Terminal two: Terminal three: Terminal four:

And using the following sequence on a decoder provide the above sequence twice as shown:

. First Second A1 B1 A2 B

The first decoder outputs Y01 Y11 Y21 Y

The second decoder outputs Y02 Y12 Y22 Y

For first stepper inputs T1 T2 T3 T4 Y21 Y22 Y31 Y

For second stepper inputs T1 T2 T3 T4 Y01 Y02 Y11 Y

Voice recorder/playback circuit

The block diagram

Minimization address pin’s To play back the voice from this IC need 9 address pin’s But I use the push button mode which is more difficult to display voice

Infra red transmitter circuit

Infra reed receiver circuit

The block diagram

Factors of safety Using a photo coupler (moc3020) It is to isolate the control circuit from the power circuit and it is put on all H-bridges inputs

Using free wheeling diodes It is used to free wheel the reverse current from the motors to the H- bridge and avoiding damaging it H-bridge sensitive for reverse current

The difficulties The magnitude of the system is too big and the need of control bins are big too, that is 8 DC motors and 3 bins for each which is 24 bin and 5 stepper motors and 4 bins for each to control which is 20 bin and 12 bins for the voice circuit, 4 bins for the commands from the ir decoder The synchronization between the two microcontroller which is too difficult. The MICANICAL STRUCTURE.

The computation of current which mean the torque available in each motor and match it with the mechanical and springs. Some devices access which does not exist in nablus and some time in Palestine like the distance sensor, IR decoder and encoder, the motors which I bring them from more than 25 scrap printers Changing the stepper to DC motors

I learned in this project pic-c language and how to use it to program a robot. Breaking the barrier of fear of the robotics technology. Many software’s and programs like Talk it program, eagle, workbench and multizem Now I am good in compacting the electrical circuits by hand. learning lathe skills, welding, and mechanical torque computation.

Additions The infra reed decoder and encoder which increase the command availability. The number of languages. The distance sensor

Conclusion I did my robot design as I want which speak in three languages Arabic, English and Spanish And its really the first one in my university And the following is the end result at this time

The end result

Any Questions

THANK YOU…