Gregory Rossano

Toward safe close-proximity human-robot interaction with standard industrial robots

Allowing humans and robots to interact in close proximity to each other has great potential for increasing the effectiveness of human-robot teams across a large variety of domains. However, as we move toward enabling humans and robots to interact at ever-decreasing distances of separation, effective safety technologies must also be developed. While new, inherently human-safe robot designs have been established, millions of industrial robots are already deployed worldwide, which makes it attractive to develop technologies that can turn these standard industrial robots into human-safe platforms. In this work, we present a real-time safety system capable of allowing safe human-robot interaction at very low distances of separation, without the need for robot hardware modification or replacement. By leveraging known robot joint angle values and accurate measurements of human positioning in the workspace, we can achieve precise robot speed adjustment by utilizing real-time measurements of separation distance. This, in turn, allows for collision prevention in a manner comfortable for the human user.We demonstrate our system achieves latencies below 9.64 ms with 95% probability, 11.10 ms with 99% probability, and 14.08 ms with 99.99% probability, resulting in robust real-time performance.

Easy robot programming concepts: An industrial perspective

One of the key challenges for industrial robotics is the high level of expertise and effort required to program a robust, production-quality robot system. In most cases, a highly trained specialist is required to setup a system, which drives up the installation costs. Standard text-based methods for programming robots oftentimes result in programs that are difficult to maintain due to their complex program structure and editing methods. This is a major issue in todays manufacturing environment where product changeover is often measured in months. This paper identifies some of the major difficulties in creating robot programs, distinguishing between creating and maintaining the logical program structure and creating robot paths. Next it describes several recent attempts to simplify industrial robot programming, focusing on those two aspects. This paper then analyzes the applicability, strengths and weakness of various approaches assessing them in light of novice, intermediate and advanced users. Lastly, some recommendations are given for further development in this area of simplifying industrial robot programming.

Vision-guided robotic assembly using uncalibrated vision

Many consumer and industrial electronics assemblies are predominantly repetitive manual tasks due to low startup costs and high flexibility. This allows the producer to easily scale back, increase or modify production to respond to the rapidly changing marketplace. However with the rising wages in low-cost countries, and ergonomics and other health concerns, the electronics industries look the automation solution again. The challenge for electronics product assembly automation is how to precisely aligning assembly features on small component for small part tight tolerance assemblies in quickly reconfigurable production. Traditional automation or teach/repeat robotic automation is often prohibitive because of costly fixtures and too time consuming setup and ramp-up. This paper introduces a vision-guided robotic assembly method using uncalibrated vision. The conventional methods of vision-guided robotics in assembly automation solutions (e.g. traditional calibration and visual servoing) cannot perform the assemblies with the grasp error and visually inaccessible assembly features. The proposed vision-guided assembly system based on camera space manipulation (CSM) method, on the other hand, relies on a local calibration method to achieve the high accuracy alignment for the final assembly. Experimental verification is performed to test the accuracy of the alignment, the robustness to grasp error, and easy reconfiguration. Under one camera configuration, the 2D vision-guided assembly robot system successfully assembly the ideal test parts within sub-millimeter tolerance with no manual calibration.

A two-phase gripper to reorient and grasp

This paper introduces the design of novel two-phase fingers to passively reorient objects while picking them up. Two-phase refers to a change in the finger-object contact geometry, from a free spinning point contact to a firm multipoint contact, as the gripping force increases. We exploit the two phases to passively reorient prismatic objects from a horizontal resting pose to an upright secure grasp. This problem is particularly relevant to industrial assembly applications where parts often are presented lying on trays or conveyor belts and need to be assembled vertically. Each two-phase finger is composed of a small hard contact point attached to an elastic strip mounted over a V-groove cavity. When grasped between two parallel fingers with low gripping force, the object pivots about the axis between the contact points on the strips, and aligns upright with gravity. A subsequent increase in the gripping force makes the elastic strips recede into the cavities letting the part seat in the V-grooves to secure the grasp. The design is compatible with any type of parallel-jaw gripper, and can be reconfigured to specific objects by changing the geometry of the cavity. The two-phase gripper provides robots with the capability to accurately position and manipulate parts, reducing the need for dedicated part feeders or time-demanding regrasp procedures.

Lead-through robot teaching

This paper presents a lead-through method and device for industrial robots and more particularly the design and calibration of a portable lead-through teaching device. Most industrial robots are programmed by a teach-and-playback approach. In some applications, maneuvering robots using the joystick or keypad on the teach pendant along the desired path is not easy or intuitive. To solve this problem, lead-through teaching methodologies have been developed by researchers from both academia and industries for more efficient and intuitive teaching of discrete point or continuous-path robot programs. We developed a portable lead-through teaching device, which is designed to be calibrated by moving the device to predetermined reference poses.

Vision-guided robot alignment for scalable, flexible assembly automation

This paper introduces a vision-guided alignment method that aims at closing the gap between a manual assembly and a fully automatic assembly. It is intended to be used for assembly of small parts in a highly agile production scenario, which employs both human workers and robots in the same line, with a frequent need for reconfiguration. The proposed method is for precisely aligning assembly features for small part, tight tolerance assemblies which are typically found in electronic (consumer/industrial) products, by utilizing a robot guided by one or more cameras. The conventional methods of vision-guided robotics in assembly automation solutions (e.g. traditional calibration and visual servoing) cannot perform the assemblies with a grasp error and visually inaccessible assembly features. The vision-guided alignment system that utilizes a camera space manipulation control process, on the other hand, relies on the CAD model of the components with a local calibration method to achieve the high accuracy alignment for the final assembly. Experimental verification is performed to test the accuracy of the alignment, the robustness to grasp error, and the automatic initialization function. Under a two camera configuration, the developed 3D vision guided assembly robot system successfully assembles the ideal test parts within sub-millimeter tolerance with no manual calibration.

Small part assembly using partial fixturing technique

This paper presents a method for assembling small parts typically found in consumer electronics such as cell phones and PDAs. Unlike traditional automation solutions that require parts be fully fixed, the proposed method allows a part, when pushed, to move in a partially constrained manner relative to its fixture. The pushing motion comes from the mating part gripped by the robot. The fixture and the pushing motion are designed such that the motion of the part within the fixture will correct the misalignment between the two parts. After the alignment is achieved, the assembly is accomplished either by the continuation of the same pushing motion or another motion. Due to the elimination of the accurate fixture, the presented method provides an inexpensive and robust alternative for assembling small parts.

Ultra-flexible production systems for automated factories

Conveyor based transportation systems are used in today manufacturing environments. The main concept we introduce in this paper is using mobile platforms to move parts, tools and fixtures between workstations in a manufacturing environment instead of conveyors. A conveyor-based production system is a fixed transportation system, hard mounted and not reconfigurable, any change in the conveyors path is costly, time-consuming and difficult. Mobile platforms allow for a more flexible manufacturing environment as it only requires a change in the software to reroute the transportations paths and accommodate the changes to the production flow and workstations. This concept paper addresses two objectives: 1) describe some of the existing mobile platform used in industry today 2) introduce the concepts and a simulation of the ultra-flexible production system.

Service robots: An industrial perspective

This paper presents the overview and the introduction of commercialized robotic products in the industrial service, maintenance and repair sectors. General facts of the industrial service are briefly described, and then we focus on four specific applications including motor /generator inspection, solar panel inspection /cleaning, tank inspection and pipe inspection. For each application, service process characteristics, operational details, technical challenges, requirements are described. Robotics solutions with commercialized products of each application area were introduced and detailed with special features and specification.

Easy robot path programming concepts: An industrial perspective on path creation

One of the key challenges for industrial robotics is the high level of expertise and effort required to program a robust, production-quality robot system. In most cases, a highly trained specialist is required to setup a system, which drives up the installation costs. It can also be difficult and time consuming even for an expert programmer to manually program long, complex robot paths. This is a major issue in todays manufacturing environment where product lifetime is often measured in months. This paper identifies some of the major difficulties in creating robot programs, focusing primarily on issues related to creating and editing a robot path. Next it describes several recent attempts to simplify industrial robot path programming. This paper then analyzes the applicability, strengths and weakness of various approaches assessing them in light of novice, intermediate and advanced users. Lastly, some recommendations are given for further development in this area of simplifying industrial robot path programming.