Development of Mechanism for Humanoid Robot Eyes-Head Coordinated Movements
Anthropomorphic humanoid robot is much like human which can interact with its environment just like human being. A group of electrical engineers of University of Gujrat (UOG) had developed an anthropomorphic humanoid robot head that included mechanical structure of the two eyes and their mechanism o
2025-06-28 16:26:40 - Adil Khan
Development of Mechanism for Humanoid Robot Eyes-Head Coordinated Movements
Project Area of Specialization RoboticsProject SummaryAnthropomorphic humanoid robot is much like human which can interact with its environment just like human being. A group of electrical engineers of University of Gujrat (UOG) had developed an anthropomorphic humanoid robot head that included mechanical structure of the two eyes and their mechanism of motion. This system consisted of 2 degrees of freedom (DOF) of eyes. 1 DOF for left right movement called pan and 1 DOF for up down movement called tilt. Smooth pursuing motion of eyeball achieved with the help of PWM signals set to rotate servo motors on desired positions and two video cameras each of 120 degrees field of view to monitor the suspicious activities. Human eye mechanism for angle of convergence was main focusing point on the development of all specifications for eyes movement. This Anthropomorphic humanoid robot head was given name as University of Gujrat Robot 1 (UOG-R1). The mechanical structure of the eyes was not perfect, and this project did not work well as desired. So, it was need of hour to improve its mechanical structure and working. Our project is the extension of UOG-R1 and has been named to University of Gujrat Humanoid Robot 1(UOG-HR1). The basic purpose of this project is to improve the mechanical structure and working of eyes and to develop the mechanical structure of neck and face that resembles to human. This project also includes mouth’s movement mechanism as well as eye-head coordination control system for a humanoid robot. The entire system consists of humanoid eye-head coordination of robot with 2 DOF that are pan and tilt of eyes and 2 DOF pan and tilt of neck movement mechanism. PWM signals set is used to drive servo motors on desire position for movement, while eyes-head coordinated control involves image processing.
Project ObjectivesThe aims and objectives of this project are:
- Improvement in eyes movement mechanism
- Improvement in mechanical structure of eyes and head
- Development of eye-head coordination control for UOG-R1
METHODOLOGY
Video Streaming
Cameras are the main source of exploration space for the humanoid robot. The project uses two USB cameras. Each of the cameras is mounted inside the eye of the of the UOG-HR1. The cameras define the observable space of the robot. Both cameras collect the images of the point of interest at the same time resulting in a stereo vision. The collected data is sent to Raspberry Pi through the USB data transfer cable that is built-in with the USB cameras.
Image Processing
The collected data from the exploratory space which is fed to the USB port of the Raspberry Pi is processed using the MATLAB. MATLAB is used for image processing and developing algorithms to facilitate the learning process of the robot. The image is processed via defining a region of interest through a rectangular window whose coordinates get updated with respect to the new coordinates of the object. These new coordinates are because of the coordinated motion of eyes and head of the robot based on the instructions from the position control.
Position Control
Position control in UOG-HR1 is just like brain in a human. It is part of this system that decides when to turn on motors and when to turn off based on the acquired position fed by the rotary encoder that is mounted to the shaft of each of the geared dc motor. It uses Pulse Width Modulation (PWM) technique for controlling each of the motors. The motor rotates according to the pulse width of the of the signal that defines the duty cycle of the motor. This produces a precise movement of the motors.
Algorithm
The algorithms can be subdivided into the algorithm for learning and the algorithms developed for control.
(a) Learning Algorithm
Supervised learning has been adopted for the learning of UOG-HR1. The lists of the objects with their attributes are to be provided to the UOG-HR1 and it has to learn by experimentation to develop its own approach about the detection of the objects. An algorithm is to be developed for its learning.
(b) Control Algorithm
The control algorithm defines when to do and what to do. A basic algorithm is as follows:
| Motor Number | Function |
| 1 | Left Eye Tilt |
| 2 | Left Eye Pan |
| 3 | Right Eye Tilt |
| 4 | Right Eye Pan |
| 5 | Head Tilt |
| 6 | Head Pan |
| 7 | Mouth Tilt |
Loop {
Read ()
If left eye tilt is required
rotate motor 1
elseif left eye pan is required
rotate motor 2
elseif right eye tilt is required
rotate motor 3
elseif right eye pan is required
rotate motor 4
elseif head tilt is required
rotate motor 5
elseif head pan is required
rotate motor 6
elseif mouth tilt is required
rotate motor 7
}
Motor Number
1
2
3
4
5
6
7
Benefits of the ProjectIn today’s world, robotics is involved in most of the tasks of humans. With rapid development in the technology, solutions to technical problems urge us for the development of new robots. The new robots are able to perform many human activities. They can interact with humans and environment. These robots not only interact with the environment but also perform many heavy-duty industrial tasks. Humanoid robots not only perform human actions but also help scientists, engineers, and medical professionals to deeply understand human conduct in various environments and situations as well. As robotics is becoming more and more popular, thoughts are being transformed to robotic technology. Today, humanoid robots help in education, entertainment, research and space exploration, personal assistance and caregiving, search and rescue, healthcare, public relations, manufacturing, and maintenance. Upcoming robots will be able to do variety of tasks for humans which are tough, boring, unsafe, or unpleasant. The focus in the research related to robotics is the improvement of current technology that meets the user requirement. It will not be wrong to say that robots are playing key role in military and industrial applications.
Technical Details of Final DeliverableThe 3D CAD model contains 24 different robotic parts. 3D printing of these parts has been done. Acrylonitrile butadiene styrene is used as facial material for the model because of flexibility and heat resistant properties while the base is printed using Polylactic acid (PLA) material because of its high strength property.
Eyes Structure
There are many ideas regarding mechanical structure design of eyes as well as some ideas about implementation. In this project initially, a frame was made along with servo motors for horizontally eyes’ movement (pan). Two motors were coupled directly with two eyes for up and down (tilt) movement. This eyes’ structure is better than previous eyes’ structure, because in this system every motor drives each eye one degree with one degree of movement of shaft of the motor. It increases the efficiency of eyes’ system as well.
Neck Structure
There are also many ideas regarding mechanical structure of neck as well as its implementation. In this project, initially a gear system was developed with shaft of a servo motor and an axial related to this gear system for tilt movement of neck. A stainless-steel plate related to this axial and another servo was set on this plate for pan movement of neck. Similarly, a third servo motor related to this system and head structure through a gear system for swing movement of head. This system is not very good, because the length of the neck is longer than a normal human being also there is a friction in gears coupled with servos and the weight of this system is greater than requirement.
Eye Head Coordination
There are a lot of image processing techniques regarding eye-head coordination to detect and track the object. In this project image processing has been done by using MATLAB which is quite easy and simple way. Cameras are attached with eyes to take video streaming for detection and tracking of object with the movement of servo motors attached with eyes as well as neck.
Final Deliverable of the Project Hardware SystemCore Industry SecurityOther IndustriesCore Technology RoboticsOther TechnologiesSustainable Development Goals Industry, Innovation and InfrastructureRequired Resources| Elapsed time in (days or weeks or month or quarter) since start of the project | Milestone | Deliverable |
|---|---|---|
| Month 1 | Literature Review | Done |
| Month 2 | Literature Review | Done |
| Month 3 | 3D Printing & Assembly | Done |
| Month 4 | 3D Printing & Assembly | Done |
| Month 5 | Developing Methodology | Done |
| Month 6 | Developing Methodology | Done |
| Month 7 | Simulation Analysis and Results | To be done |
| Month 8 | Implementation | To be done |
| Month 9 | Implementation | To be done |
| Month 10 | Comparison of Actual Results with simulation results | To be done |
| Month 11 | Discussion and Conclusion | To be done |
| Month 12 | Project Report Writing | To be done |