31 research outputs found
The design, kinematics and torque analysis of the self-bending soft contraction actuator
This article presents the development of a self-bending contraction actuator (SBCA) through analysis of its structure, kinematics, and torque formulas, and then explores its applications. The proposed actuator has been fabricated by two methods to prove the efficiency of the human body inspiration, which represents the covering of human bones by soft tissues to protect the bone and give the soft texture. The SBCA provides bending behaviour along with a high force to-weight ratio. As with the simple pneumatic muscle actuator (PMA), the SBCA is soft and easy to implement. Both the kinematics and the torque formula presented for the SBCA are scalable and can be used with different actuator sizes. The bending actuator has been tested under an air pressure up to 500 kPa, and the behaviour of its bending angle, parameters, dimensions, and the bending torques have been illustrated. On the other hand, the experiments showed the efficient performances of the actuator and validate the proposed kinematics. Therefore, the actuator can be used in many different applications, such as soft grippers and continuum arms
IR sensors array for robots localization using K means clustering algorithm
The position of multi-robot system in an indoor localization system is successfully estimated using a new algorithm. The localization problem is resolved by using an array of IR receiver sensors distributed uniformly in the environment. The necessary information about the localization development is collected by scanning the IR sensor array in the environment. The scheme of scanning process is done column by column to recognize and mention the position of IR receiver’s sensors, which received signals from the IR transmitter that is fixed on the robot. This principle of scanning helps to minimize the required time for robot localization. The k-means clustering algorithm is used to estimate the multi-robot locations by isolating the labeled IR receivers into clusters. Basically the multi-robot position is estimated to be the middle of each cluster. Simulation results demonstrate the advances algorithm in estimation the multi-robot positions for various dimensional IR receiver’s array
Collaborative system and multi robots based on pneumatic muscle actuator
Designing a multi-robot system provides numerous advantages for many applications, such as low cost, multi-tasking and more efficient group work. While the rigidity of the robots used in industrial and medical application increase the probability of risk of injury. Therefore, many researches are done to increase the safety factor for robot-human interaction, as a result, either the separated between the human and robot is suggested or the force shutdown to robot system is applied. These solutions might be useful for industrial applications, nonetheless it is not for medical and the application require the direct interaction between the human and machine. To overcome the rigidity problem, a soft pneumatic muscle actuator PMA is used in this thesis to design a fully soft robot arm.The performances and the behaviours of these actuators are tested to enhance the force formula for the contraction and the extension PMAs. General length formulas are proposed in terms of the initial length in addition to the structure-based formulas for the tensile force and length. Three different novel actuators are proposed together with their kinematics. These actuators include: the self-bending contraction actuator SBCA, the double-bend pneumatic muscle actuator DB-PMA and the circular pneumatic muscle actuator CPMA. The presented actuators are used with the simple contraction and extension actuators to design different novel structures of continuum arms and end effectors. Then an efficient control system is proposed by using a parallel structure of the neural network NN and proportional P controller (PNNP controller). The presented continuum arms formed a multiple robot system to perform several tasks under the PNNP controller
A circular pneumatic muscle actuator (CPMA) inspired by human skeletal muscles
This paper illustrates the design, implementation and kinematics of a novel circular pneumatic muscle actuator (CPMA), inspired by the skeletal muscles of a human. The variation of the inner diameter of this actuator is a unique feature. Furthermore, CPMA produces a radial force towards its centre by increasing the diameter of the actuator itself in addition to the reduction in the inner diameter. These performances make the presented actuator suitable to use in numerous applications. The grasping by a soft gripper is chosen as an application to design an efficient soft gripper by using single and multiple CPMAs
Novel models for the extension pneumatic muscle actuator performances
This paper illustrates the design, implementation
and modelling of the extensor pneumatic muscle actuator
(PMA). The extensor soft actuator has a vital feature of
ability to bend and extend, and that give it the flexibility to
use in numerous applications. The extended behaviour of
this actuator is modelled mathematically to be used to
predict the length of a wide range of actuators at different
air pressure amounts and make the position control of such
type of actuator easier and precise. Moreover, the
contraction force formula is modified to describe the
pushing force for the extensor actuator. The bending
behaviour of single muscle is explained and a 4-PMA
continuum arm has been constructed to study its
performance and model the bending angle
Design, kinematics, and controlling a novel soft robot arm with parallel motion
This article presents a novel design for a double bend pneumatic muscle actuator (DB-PMA) inspired by snake lateral undulation. The presented actuator has the ability to bend in opposite directions from its two halves. This behavior results in horizontal and vertical movements of the actuator distal ends. The kinematics for the proposed actuator are illustrated and experiments conducted to validate its unique features. Furthermore, a continuum robot arm with the ability to move in parallel (horizontal displacement) is designed with a single DB-PMA and a two-finger soft gripper. The performance of the soft robot arm presented is explained, then another design of the horizontal motion continuum robot arm is proposed, using two self-bending contraction actuators (SBCA) in series to overcome the payload effects on the upper half of the soft arm
Cooperative project by self-bending continuum arms
Designing a multi-robot system provides numerous
advantages for many applications such as low cost, multi-tasking and more efficient group work. However, the rigidity of the robots used in industrial and medical applications increases the probability of injury. Therefore, lots of research is done to increase the safety factor for robot-human interaction. As a result, either separation between the human and robot is suggested, or the force shutdown to the robot system is applied.
These solutions might be useful for industrial applications, but it is not for medical applications as a direct interaction between the human and the machine is required. To overcome the rigidity problem, a soft robot arm is presented in this paper. Studying the structure and performance of a contraction pneumatic muscle
actuator (PMA) is illustrated, then useful strategies are used to implement a multi PMA continuum arm to increase the performance options for such types of the actuator. Moreover, twin arms are constructed to organise a collaborative project depending on the performance abilities of the proposed arms and end effectors
Vision-Based Soft Mobile Robot Inspired by Silkworm Body and Movement Behavior
Designing an inexpensive, low-noise, safe for individual, mobile robot with an efficient vision system represents a challenge. This paper proposes a soft mobile robot inspired by the silkworm body structure and moving behavior. Two identical pneumatic artificial muscles (PAM) have been used to design the body of the robot by sewing the PAMs longitudinally. The proposed robot moves forward, left, and right in steps depending on the relative contraction ratio of the actuators. The connection between the two artificial muscles gives the steering performance at different air pressures of each PAM. A camera (eye) integrated into the proposed soft robot helps it to control its motion and direction. The silkworm soft robot detects a specific object and tracks it continuously. The proposed vision system is used to help with automatic tracking based on deep learning platforms with real-time live IR camera. The object detection platform, named, YOLOv3 is used effectively to solve the challenge of detecting high-speed tiny objects like Tennis balls. The model is trained with a dataset consisting of images of  Tennis balls. The work is simulated with Google Colab and then tested in real-time on an embedded device mated with a fast GPU called Jetson Nano development kit. The presented object follower robot is cheap, fast-tracking, and friendly to the environment. The system reaches a 99% accuracy rate during training and testing. Validation results are obtained and recorded to prove the effectiveness of this novel silkworm soft robot. The research contribution is designing and implementing a soft mobile robot with an effective vision system
Active soft end effectors for efficient grasping and safe handling
The end effector is a major part of a robot system and it defines the task the robot can perform. However, typically, a gripper is suited to grasping only a single or relatively small number of different objects. Dexterous grippers offer greater grasping ability but they are often very expensive, difficult to control and are insufficiently robust for industrial operation. This paper explores the principles of soft robotics and the design of low-cost grippers able to grasp a broad range of objects without the need for complex control schemes. Two different soft end effectors have been designed and built and their physical structure, characteristics and operational performances have been analysed. The soft grippers deform and conform to the object being grasped, meaning they are simple to control and minimal grasp planning is required. The soft nature of the grippers also makes them better suited to handling fragile and delicate objects than a traditional rigid gripper