Design and Field Evaluation of a Robotic Apple Harvesting System with a 3D-Printed Soft-Robotic End-Effector

2019 ◽  
Vol 62 (2) ◽  
pp. 405-414 ◽  
Author(s):  
Cameron J. Hohimer ◽  
Heng Wang ◽  
Santosh Bhusal ◽  
John Miller ◽  
Changki Mo ◽  
...  

Abstract. Fresh market apple harvesting is a difficult task that relies entirely on manual labor. Much research has been done on the development of mechanical harvesting techniques. Several selective harvesting robots have been developed for research studies, but there are no commercially available robotic systems. This article discusses the design and development of a novel pneumatic 3D-printed soft-robotic end-effector to facilitate apple separation. The end-effector was integrated into a robotic system with five degrees of freedom that was designed to simplify the picking sequence and reduce costs compared to previous versions. Apples were successfully harvested using the low-cost robotic system in a commercial orchard during the fall 2017 harvest. A detachment success rate on attempted apples of 67% was achieved, with an average time of 7.3 s per fruit from separation to storage bin. By conducting this study in an orchard where problematic apples were not removed to increase the detachment success rate, current pruning and thinning practices were assessed to help lay the foundation for future studies and develop strategies for successfully harvesting apples that are difficult to detach. Keywords: Apple catching, Apples, Automated harvesting, Field experimentation, Harvesting robot, Soft-robotic gripper.

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 21
Author(s):  
Bruno Lourenço ◽  
Vitorino Neto ◽  
Rafhael de Andrade

The Hands exert a vital role in the simplest to most complex daily tasks. Losing the ability to make hand movements, which is usually caused by spinal cord injury or stroke, dramatically impacts the quality of life. In order to counteract this problem, several assisting devices have been proposed, but they still present several usage limitations. The marketable orthoses are generally either the static type or over-expensive active orthosis that cannot perform the same degrees of freedom (DoF) that a hand can do. This paper presents a conceptual design of a tendon-driven mechanism for hand’s active orthosis. This study is a part of an effort to develop an effective and low-cost hand’s orthosis for people with hand paralysis. The tendon design proposed was thought to comply with some requisitions such as lightness and low volume, as well as fit with the biomechanical constraints of the hand joints to enable a comfortable use. The mechanism employs small cursors on the phalanges to allow the tendons to run on the dorsal side and by both sides of the fingers, allowing 2 DoF for each finger, and one extra tendon enlarges the hands’ adduction nuances. With this configuration, it is simple enough to execute the flexion and extension movements, which are the most used movements in daily actives, using one single DC actuator for one DoF to reduce manufacturing costs, or with more DC actuators to enable more natural hand coordination. This system of actuation is suitable to create soft exoskeletons for hands easily embedded into 3D printed parts, which could be merged over statics thermoplastic orthosis. The final orthosis design allows dexterous finger movements and force to grasp objects and perform tasks comfortably.


2021 ◽  
Author(s):  
Yara Almubarak ◽  
Michelle Schmutz ◽  
Miguel Perez ◽  
Shrey Shah ◽  
Yonas Tadesse

Abstract Underwater exploration or inspection requires suitable robotic systems capable of maneuvering, manipulating objects, and operating untethered in complex environmental conditions. Traditional robots have been used to perform many tasks underwater. However, they have limited degrees of freedom, manipulation capabilities, portability, and have disruptive interactions with aquatic life. Research in soft robotics seeks to incorporate ideas of the natural flexibility and agility of aquatic species into man-made technologies to improve the current capabilities of robots using biomimetics. In this paper, we present a novel design, fabrication, and testing results of an underwater robot known as Kraken that has tentacles to mimic the arm movement of an octopus. To control the arm motion, Kraken utilizes a hybrid actuation technology consisting of stepper motors and twisted and a coiled fishing line polymer muscle (TCP FL ). TCPs are becoming one of the promising actuation technologies due to their high actuation stroke, high force, light weight, and low cost. We have studied different arm stiffness configurations of the tentacles tailored to operate in different modalities (curling, twisting, and bending), to control the shape of the tentacles and grasp irregular objects delicately. Kraken uses an onboard battery, a wireless programmable joystick, a buoyancy system for depth control, all housed in a three-layer 3D printed dome-like structure. Here, we present Kraken fully functioning underwater in an Olympic-size swimming pool using its servo actuated tentacles and other test results on the TCP FL actuated tentacles in a laboratory setting. This is the first time that an embedded TCP FL actuator within elastomer has been proposed for the tentacles of an octopus-like robot along with the performance of the structures. Further, as a case study, we showed the functionality of the robot in grasping objects underwater for field robotics applications.


2010 ◽  
Vol 4 (3) ◽  
Author(s):  
Shorya Awtar ◽  
Tristan T. Trutna ◽  
Jens M. Nielsen ◽  
Rosa Abani ◽  
James Geiger

This paper presents a new minimally invasive surgical (MIS) tool design paradigm that enables enhanced dexterity, intuitive control, and natural force feedback in a low-cost compact package. The paradigm is based on creating a tool frame that is attached to the surgeon’s forearm, making the tool shaft an extension of the latter. Two additional wristlike rotational degrees of freedom (DoF) provided at an end-effector that is located at the end of the tool shaft are manually actuated via a novel parallel-kinematic virtual center mechanism at the tool input. The virtual center mechanism, made possible by the forearm-attached tool frame, creates a virtual two-DoF input joint that is coincident with the surgeon’s wrist, allowing the surgeon to rotate his/her hand with respect to his/her forearm freely and naturally. A cable transmission associated with the virtual center mechanism captures the surgeon’s wrist rotations and transmits them to the two corresponding end-effector rotations. This physical configuration allows an intuitive and ergonomic one-to-one mapping of the surgeon’s forearm and hand motions at the tool input to the end-effector motions at the tool output inside the patient’s body. Moreover, a purely mechanical construction ensures low-cost, simple design, and natural force feedback. A functional decomposition of the proposed physical configuration is carried out to identify and design key modules in the system—virtual center mechanism, tool handle and grasping actuation, end-effector and output joint, transmission system, tool frame and shaft, and forearm brace. Development and integration of these modules leads to a proof-of-concept prototype of the new MIS tool, referred to as FlexDex™, which is then tested by a focused end-user group to evaluate its performance and obtain feedback for the next stage of technology development.


2020 ◽  
Vol 2 (1) ◽  
pp. 72
Author(s):  
Stefano Lumetti ◽  
Perla Malagò ◽  
Dietmar Spitzer ◽  
Sigmund Zaruba ◽  
Michael Ortner

Properties such as high resolution, contactless (and thus wear-free) measurement, low power consumption, robustness against temperature and contamination as well as low cost make magnetic position and orientation systems appealing for a large number of industrial applications. Nevertheless, one major practical challenge is their sensitivity to fabrication tolerances. In this work, we propose a novel method for magnetic position system calibration based on the analytical computation of the magnetic field and on the application of an evolutionary optimization algorithm. This scheme enables the calibration of more than 10 degrees of freedom within a few seconds on standard quad-core ×86 processors, and is demonstrated by calibrating a highly cost-efficient 3D-printed 3-axis magnetic joystick.


Author(s):  
Niko Giannakakos ◽  
Ayse Tekes ◽  
Tris Utschig

Abstract Mechanical engineering students often learn the fundamentals of vibrations along with the time response of underdamped, critically damped, and overdamped systems in machine dynamics and vibrations courses without any validation or visualization through hands-on experimental learning activities. As these courses are highly theoretical, students find it difficult to connect theory to practical fundamentals such as modeling of a mechanical system, finding components of the system using experimental data, designing a system to achieve a desired response, or designing a passive vibration isolator to reduce transmitted vibrations on a primary system. Further, available educational laboratory equipment demonstrating vibrations, dynamics and control is expensive, bulky, and not portable. To address these issues, we developed a low-cost, 3D printed, portable laboratory equipment (3D-PLE) system consisting of primary and secondary carts, rail, linear actuator, Arduino, and compliant flexures connecting the carts. Most of the educational systems consist of a mass limited to 1DOF motion and multi-degrees of freedom systems can be created using mechanical springs. However, in real-world applications oscillations in a system are not necessarily due to mechanical springs. Anything flexible, or thin and long, can be represented by a spring as seen in torsional systems. We incorporated 3D printed and two monolithically designed rigid arms connected with a flexure hinge of various stiffness. The carts are designed in a way such that two flexible links can be attached from both sides and allow more loads to be added on each cart. The system can be utilized to demonstrate fundamentals of vibrations and test designs of passive isolators to dampen the oscillations of the primary cart.


Author(s):  
Daniel M. Sakai ◽  
Heather Skrzypczak ◽  
Pablo Nejamkin ◽  
Maria Clausse ◽  
Carlos Bulant ◽  
...  

Endotracheal intubation (EI) in domestic cats is an important skill that veterinary students learn in order to perform anesthesia safely in this species. Implementing a 3D-printed larynx model (LaryngoCUBE) during the instruction process may improve student’s learning of EI in felines. Twenty-two third-year students performed EI in cats with standard training (ST), and 16 students trained with the model (MT) the day before the laboratory. It was evaluated whether training with the model decreases the time and number of EI attempts, students’ perceived difficulty performing EI using a visual analog score (VAS; 0 cm = very easy, 10 cm = extremely difficult; median [minimum–maximum]), and the incidence of failure to perform EI. The EI time on ST (58 [18–160] seconds) was longer, but not statistically different from MT (29 [13–120] seconds; p = .101). The number of EI attempts on ST (2 [1–3]) was higher than MT (1 [1–3]; p = .005). The VAS on the ST and MT were 4.5 (0.0–10.0) cm and 3.0 (0.2–10.0) cm, respectively ( p = .029). The failure rate was 27% on the ST and 25% on the MT ( p = 1.000). Students who practiced with a larynx model took fewer attempts to perform EI, tended to be faster, and found that EI was easier. However, the EI success rate in MT was not improved.


Author(s):  
Alfiero Leoni ◽  
Vincenzo Stornelli ◽  
Giuseppe Ferri ◽  
Giancarlo Orengo ◽  
Vito Errico ◽  
...  

We here present a 10-17 Degrees of Freedom (DoF) sensory gloves for Smart Healthcare implementing an energy harvesting architecture, aimed at enhancing the battery lasting when powering the electronics of the two different types of gloves, used to sense fingers movements. In particular, we realized a comparison in terms of measurement repeatability and reliability, as well as power consumption and battery lasting, between two sensory gloves implemented by means of different technologies. The first is a 3D printed glove with 10 DoF, featuring low-cost, low-effort fabrication and low-power consumption. The second is a classical Lycra® glove with 14 DoF suitable for a more detailed assessment of the hand postures, featuring a relatively higher cost and power consumption. An electronic circuitry was designed to gather and elaborate data from both types of sensory gloves, differing for number of inputs only.  Both gloves are equipped with flex sensors and in addiction with the electronics (including a microcontroller and a transmitter) allow the control of hand virtual limbs or mechanical arts in surgical, military, space and civil applications.Six healthy subjects were involved in tests suitable to evaluate the performances of the proposed gloves in terms of repeatability, reproducibility and reliability. Particular effort was devoted to increase battery lasting for both glove-based systems, with the electronics relaying on Radio Frequency, Piezoelectric and Thermoelectric harvesters. The harvesting part was built and tested as a prototype discrete element board, that is interfaced with an external microcontroller and a radiofrequency transmitter board. Measurement results demonstrated a meaningful improvement in battery operation time up to 25%, considering different operating scenarios.


2020 ◽  
Vol 318 ◽  
pp. 01039
Author(s):  
Abdalla M. Omar ◽  
Mohamed Hassan

Every year there are about 3500-5200 people suffering from upper limb amputations, most of which are wrist disarticulation and transcarpal. This paper investigates current upper limb prostheses and presents the disadvantages of current prostheses, including limited degrees of freedom (DOF), limited range of motion, weight, customizability, and appearance. The proposed design is the first stage of a series of papers that proposes designs that are compatible with shape morphing materials. The use of these materials as actuators allows the development and design of more advanced upper limb prostheses. Therefore, the prosthesis is modelled as needed for patients with transcarpal/wrist disarticulation amputations. The proposed model has 27 degrees of freedom (DOF), reduced weight, low cost, improved appearance, and is printable to fit.


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