Motion Control System Includes Solid-State, Embedded PC
August 27, 2010 by admin
Filed under Featured Mechatronic Articles, Motion Control, Technology
Siemens announced that an embedded PC is now available for its Simotion® P320-3 motion control applications. Providing maintenance-free controls, the Simotion P320-3 brings the power and simplicity of a PC to motion control.
The embedded PC, which features a DDR3 memory and an Intel Core2 processor, is free of wear from moving parts, such as hard disks and fans. This compact motion control system provides maximum flexibility and accommodates centralized or decentralized machine concepts for PC-based applications or for applications that require a compact size.
It is designed for many different motion control applications with its multiple onboard interfaces. They support communication over Profinet, the open industrial Ethernet standard, as well as Ethernet interfaces that run at 10 / 100 / 1000 megabit speeds. Four USB interfaces make it simple to connect a keyboard, USB stick, printer or other devices. A DVI port rounds out the links so users can attach a display or monitor. The Simotion P320-3 can also be used in a “headless” configuration without a display, monitor or front panel.
LEDs on the front indicate the operating states, making self-diagnosis easy. The integrated power supply bridges temporary power failures. In the buffered SRAM memory, the process data is saved securely even in the event of a sudden voltage drop. Monitoring functions for the batteries, temperature and program execution are also included. The Windows Embedded Standard 2009 operating system, which increases the reliability of the system, is pre-installed. Additionally, the Simotion runtime system comes installed on the Simotion P320-3.
Superior Feedback Performance in Telerobotics
August 24, 2010 by admin
Filed under Mechanical, Motion Control, Robotics, Technology
WITTENSTEIN has perfected its control loading products to provide realistic force feedback for the telerobotics market. Utilizing compact design and unique electronic linking, sidestick systems from WITTENSTEIN offer revolutionary reliability and realism for operators.
WITTENSTEIN Aerospace & Simulation has been the control loading leader in the flight simulation market for more than a decade. The Company has taken its expertise and applied it to telerobotics, where a user controls an axis or entire vehicle remotely. WITTENSTEIN’s products provide the user with feedback of the remote axis through electrical linking and force control technology.
The main features of the sidestick systems for telerobotics are superior efficiency, compact design, and electric linking with force feedback. These result in smooth operator feel, no need for additional mechanical linkages or hydraulics, and a standard off-the-shelf system solution that utilizes standard wall-outlet power. The robust nature of the WITTENSTEIN systems allow for up to 10 axes per control module.
Sample areas of application for this technology include remote product testing for reasons due to environmental or equipment restrictions.
Robotic Machining Cuts Part Lead-Time From Months To Days
August 19, 2010 by admin
Filed under Automation, Design, Industry, Manufacturing Trends, Robotics, Technology
Subtractive processes, often referred to as CNC machining, have not stood still in the rapid prototyping arena. Faster tool path generation is just one of the newer developments enabling machining to play a strong role in the rapid prototyping and direct digital manufacturing arena. Now, robotic machining has the potential to significantly affect the rapid casting arena, especially in the area of large castings. Tooling costs as well as lead times increase dramatically as parts get larger. The equipment needed to deal with the size and weight of extremely large parts becomes more rare and thus, more expensive. The larger the equipment used for these large parts, the slower it will operate due to its heavy physical characteristics. The most significant advantage that robotic machining seems to have is the fact that the robot moves independently of the work piece giving it the ability to feed as quickly on a large part as it does on a smaller, lighter part.
The US Department of Defense (DoD) has been seeking a way to reduce the cost of producing cast spare parts. The Advanced Technology Institute (ATI) currently leads several national collaborations that are developing advanced robotics capabilities and implementing both new and existing robotics technologies in response to the DoD’s need.
One collaboration is with the American Metalcasting Consortium (AMC). The ATI-managed AMC partner companies, like Clinkenbeard, are using robotics technologies to support legacy weapon systems; which could help meet the Defense Logistic Agency’s goal of dramatically shorter lead times for the production of legacy weapon systems parts. The patented Clinkenbeard® Toolingless Process proved that it could reduce lead times for military cast spare parts from six to twelve months to six to twelve days.
The results, according to ATI, also demonstrated that the Toolingless Process can reduce capital investment by as much as 35%, reduce individual parts cost by up to 20%, and improve cycle time by 25%.
Lead times often exceed a year because technical data may require reworking, including the development of a solid model of the part. But, even when a solid model is generated first, the Clinkenbeard process can supply a cast part in less than a month. The secret is computer-generated molds with no tooling.
The Toolingless Process consists of machining sand cores and molds, and is accurate. According to the company, this process can reduce the lead-time to obtain development castings by up to 90%. With this process, you can:
• eliminate the need for prototype tooling, depending on project requirements.
• make and test multiple design iterations during product development, from the simple to complex parts.
• reduce the cost of production tooling for one-of and small quantities.
• obtain accurate, prototype parts while large quantity tooling is made.
• eliminate tooling inventory.
• match exact production core materials and chemical levels so that prototype castings emulate production.
• incorporate engineering changes into high-volume production sand cores.
Clinkenbeard developed the sand machining process using CNC machining centers. By using robots with sand machining, company technicians can use the process on much larger molds and cores. Robotic technology will reduce the cost dramatically compared to the same expenditure for CNC machining centers.
Clinkenbeard
www.clinkenbeard.com
American Metal Consortium
http://amc.aticorp.org/
Defense Logistic Agency
www.dla.mil
Advanced Technology Institute (ATI)
www.aticorp.org
Iranian Robot Walks, Stands On One Leg
August 17, 2010 by admin
Filed under Robotics, Technology
Researchers at Tehran University, in Iran, unveiled last month an adult-sized humanoid robot called Surena 2.
The initial press reports in Iran’s official news media didn’t include many details, saying only it could “walk like a human being but at a slower pace” and perform some other tasks, and there were questions about the robot’s real capabilities.
IEEE Spectrum obtained more information about Surena, as well as images and videos showing that the robot can indeed walk — and even stand on one leg.
Aghil Yousefi-Koma, a professor of engineering at the University of Tehran who lead the Surena project, tells me that the goal is to explore “both theoretical and experimental aspects of bipedal locomotion.”
The humanoid relies on gyroscopes and accelerometers to remain in balance and move its legs, still very slowly, but Yousefi-Koma says his team is developing a “feedback control system that provides dynamic balance, yielding a much more human-like motion.”
Surena 2, which weighs in at 45 kilograms and is 1.45 meter high, has a total of 22 degrees of freedom: each leg has 6 DOF, each arm 4 DOF, and the head 2 DOF. An operator uses a remote control to make the robot walk and move its arms and head. The robot can also bow. Watch:
Surena doesn’t have the agile arms of Hubo, the powerful legs of Petman, or the charisma of Asimo — but hey, this is only the robot’s second-generation, built by a team of 20 engineers and students in less than two years. A first version of the robot, much simpler, with only 8 DOF, was demonstrated in late 2008.
Yousefi-Koma, who is director of both the Center for Advanced Vehicles (CAV) and the Advanced Dynamic and Control Systems Laboratory (ADCSL) at the University of Tehran, says another goal of the project is to “to demonstrate to students and to the public the excitement of a career in engineering.”
Next the researchers plan to develop speech and vision capabilities and improve the robot’s mobility and dexterity. They also plan to give Surena “a higher level of machine intelligence,” he says, “suitable for various industrial, medical, and household applications.”
The robot was unveiled by Iranian President Mahmoud Ahmadinejad on July 3rd in Tehran as part of the country’s celebration of “Industry and Mine Day.” The robot is a joint project between the Center for Advanced Vehicles and the R&D Society of Iranian Industries and Mines.
High-Torque Actuators Are Optimized For Speed & Strength
August 13, 2010 by admin
Filed under Pneumatics–Hydraulics, Technology
WITTENSTEIN announced the TPM+/TPM+ High Torque sizes 300/500. These sumo-sized actuators offer maximum rigidity and the highest torque combined with WITTENSTEIN’s signature compact design.
The new sizes 300 and 500 meet the highest requirements concerning torque, compactness and dynamics. Features include high rigidity, extreme precision and excellent performance, making the TPM+ 300/500 actuators a fundamental contribution to increase the productivity of any machine.
Technical specifications at a glance:
- Torque up to 10,000 Nm
- Compact design coupling the alpha TP+ 300/500 gearbox and 220 series motors
- Optional strengthened output bearing (special gear housing)
Giant Robotic Arm Simulates Driving a Ferrari
August 12, 2010 by admin
Filed under Robotics, Simulation, Technology
The hot-pink industrial arm whips you around while you sit in the driver’s seat

This image shows the robotic arm Ferrari simulator without a steering wheel attached. The simulator includes a force-feedback steering wheel and pedals.
Paolo Robuffo Giordano and colleagues at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, must really enjoy their jobs. Their CyberMotion Simulator is intended to realistically replicate the experience of driving a Ferrari without actually having to buy one.
Players sit in a cabin on a robot arm about 7 feet off the ground and drive a Ferrari F2007 car around a projected track. The robot arm, a type usually found in amusement parks, whips the driver around to simulate the Ferrari’s motion, according to IEEE Spectrum. You can hear the robot whine as the driver tries to turn at high speed.
The researchers wanted to use a robotic arm as a motion simulator with the goal of understanding how humans experience the sensation of motion. They figured an F1 racing game would be a good way to do it, IEEE Spectrum reports.They presented a paper on their design at the IEEE International Conference on Robotics and Automation this spring.
Universal Robotics Lauches 3D Software Compatible With Webcams
August 12, 2010 by admin
Filed under Design, Industry, Manufacturing Trends
Universal Robotics, Inc., a software engineering company, announced the launch of two simple-to-use 3D vision software products: Spatial Vision and Spatial Vision Robotics. The products can turn any pair of webcams into a highly accurate, cost-efficient 3D vision system that can be employed in virtually any setting without expensive equipment.
With Spatial Vision and Spatial Vision Robotics, a user can plug in the cameras, calibrate their space and receive highly accurate measurements in under 30 minutes. These products will expand the use of 3D vision to markets where it hasn’t been feasible before.
3D vision systems offer many benefits over their 2D counterparts, including better accuracy and object identification and tracking, which are essential features in security, engineering and robotics applications from biometrics to real-time control of machines. Despite their benefits, broad adoption of 3D vision systems has been limited in many markets because the systems can be costly to implement and maintain.
Universal’s Spatial Vision products eliminate the need for the precision mounting, specialized cameras, and time-consuming set up that is required for many 3D vision systems. Using two webcams that can be set up and calibrated within a matter of minutes, Spatial Vision and Spatial Vision Robotics can determine the 3D position of any point relative to the cameras with millimeter accuracy.
The Spatial Vision product can be easily deployed in any setting in which cameras can be installed, including laboratories, office buildings, department stores and warehouses, and is an affordable solution for anyone looking for an accurate way to observe and measure an environment. It can be employed in security applications, measuring in-store foot traffic patterns, and more scientific applications requiring object tracking and visual analytics without a wand or sensing device. Spatial Vision offers 30 percent improved accuracy over 2D systems used in object identification and tracking applications, such as facial recognition and other biometrics. It is optimized for use with popular Logitech 9000 webcams, but can be customized to work with any USB 2.0 camera.
Spatial Vision Robotics has been specially designed to be used in concert with automated machines. By adding LEDs to points of interest on moving machinery, Spatial Vision Robotics provides 3D position on the machine and its surroundings in robot coordinates as seen from the camera. The program enables 3D calibration between the extrinsic object of interest, the robot and the cameras, as well as intrinsic calibration with the cameras. It can work with any robot and is currently optimized for Yaskawa America (Motoman) SDA-series robots. Spatial Vision Robotics can be integrated with path planning and high-speed inverse kinematics to enable real-time control of robots.
Spatial Vision and Spatial Vision Robotics were created as part of the development of Universal’s signature technology, Neocortex™, a sensory-motor based form of artificial intelligence that enables moving machines to learn from their experiences and perform tasks that are unsafe or difficult for humans. Neocortex was developed over seven years with NASA and Vanderbilt University, and was funded by U.S. Department of Defense.
Interactive Tools for Mechatronics
August 11, 2010 by admin
Filed under Commentary, Technology
DOLPHIN Integration SA and Infolytica Corporation announced that their products for mixed signal simulation and electromagnetic field simulation now work together to perform mechatronic system simulation. SMASH software from DOLPHIN can directly simulate response surface models of electric motors generated in VHDL-AMS by MagNet or MotorSolve, from Infolytica, and can perform a system level simulation of the device and the control circuitry.

The multilingual and mixed-signal simulator SMASH “All-in-One” is well suited for hierarchical SoC Integration with patented features for DfY and an extensive VHDL-AMS language compliance. It serves as the cornerstone for the Virtual Fab Process enabling ViC and SoC Right-on-First-Pass Silicon.
Designing mechatronic systems requires understanding the significant interactions between the electromechanical components and the analog or digital electronics. The VHDL-AMS models are functionally equivalent to the original MagNet or MotorSolve models, but they can be evaluated quickly in a transient circuit simulation. The files can be integrated into a circuit description in SMASH to perform a simulation taking into account the interactions between the machine and control circuitry.
MagNet v7 and MotorSolve v2, with their VHDL-AMS export capabilities, are available for PC’s running Microsoft Windows XP, Vista and 7. SMASH is available identically under Windows and Linux.
Top 5 Electrical Considerations for Mechanical Engineers
August 10, 2010 by admin
Filed under Commentary, Design, Featured Mechatronic Articles
Previously, we covered mechanical considerations for electrical engineers. Now, we give the other side a chance to speak. Here are five targeted pieces of advice for mechanical engineers responsible for electromechanical systems, from the perspective of an electrical engineer.
Mechatronics systems intelligently integrate mechanical and electrical elements to perform increasingly complex and demanding functions. When designing electromechanical systems, mechanical engineers and electrical engineers may tend to emphasize the technologies, components, and design principles from their single area of expertise—which can lead to systems with higher operating costs, increased maintenance demands, and less than optimal performance. As an electrical engineer involved in helping OEMs and manufacturers design and build mechatronic systems, I’ve seen how inefficiencies and unnecessary complexity can be unintentionally designed into machines.
Better mechatronic systems can be created when mechanical engineers consider five crucial concepts while designing manufacturing systems, to derive the greatest value and efficiency electronics systems can offer to the manufacturing process.
1: Create a clean design
Good mechatronics design starts with good mechanical design – the best electronics and electrical systems cannot compensate for poor mechanical design. The most successful designs are “clean.” They feature a strong, rigid frame, using materials and structural principles to ensure that, whatever motion the machine undergoes, its long-term stability is “engineered” in.
Make sure that rigid bearings and support are used where motors are mounted on machines; this helps prevent shafts from being sheared off due to microfractures that occur because the motor shaft is mounted out of alignment with a pillow block bearing or gearbox input planetary gear. Place motors on the machine in the best location so that operators aren’t accidentally stepping on cables and connectors and causing damage; and design machine guarding with easy access points to get to motors mounted under the wing base of the machine while still protecting them against harsh environments.
Most importantly, a clean design balances mass and motion: sturdy, durable framing that withstands years of vibration and shock, combined with lighter-weight components for the moving parts of the machine. This combination helps reduce mass, delivers more energy-efficient motion, and makes it easier to size-up smaller motor/drive components for the machine. We’ve seen a lot of very innovative mechanical machine designs over the years, and a clean design makes the largest contribution to a machine’s longevity, robustness, and lowest overall cost of ownership.
2: Directly couple the motor to the load
Effective mechatronics starts with a “clean slate” design. In the past, machines were often built around a single ac motor powering a machine line shaft, to which were attached gearboxes, pulleys, sprockets, chain drives and other mechanical devices for moving individual areas of the machine in synchronization – an approach to powering manufacturing that literally can be traced back to the dawn of the Industrial Revolution.

A clean design makes the largest contribution to a machine’s longevity, robustness and lowest overall cost of ownership.
Consider replacing this architecture with individual servomotors coupled directly to the load you are moving. There are multiple design, machine cost, and operational advantages to this idea (which a surprising number of machine designs do not use). First, consider cost: every time you add a gearbox, you add multiple costs: it’s an additional point of failure, it has to be lubricated, and it needs spare parts. Plus, you add mechanical backlash that must be compensated for during machine commissioning every time you have a product changeover – motion and axes synchronization complexity that today’s intelligent drives and servomotors eliminate.
When you strategically locate servomotors as close as possible to the area of motion they are serving, the incremental cost of electric drive components is almost completely offset by eliminating the cost of mechanical components and labor that must be purchased, machined, assembled and configured. In particular, not having to stock multiple sets of sprockets, gears and cams, as well as the time involved in changeovers with mechanical drives, can really drive down the total cost of ownership for the machine.
Ultimately, this design approach greatly reduces windup and backlash, as well as improves machine commissioning time; and current state-of-the-art direct drives, direct motors, and linear motors let you run higher gains and improve the machine’s performance.
Consideration #3: Use electronic gearing and camming
Today’s electronic drives and motion control platforms give mechanical engineers, a powerful, flexible tool to improve the accuracy and performance of the machines you design. This technology lets you create a virtual “electronic line shaft” that can electronically synchronize all the drives and motors on the machine, eliminating the mechanical line shaft. In the process, you can dramatically improve axes synchronization and accuracy – from 1/16th or 1/32nd of an inch typical with mechanical line shafts, down to motion precision closer to hundredths or even thousandths of an inch with electronic line shafting.
And this synchronization can be accomplished with zero mechanical backlash – and fewer product jams. It also eliminates a host of mechanical adjustments to bring the machine online, as well as the operator adjustments each time the machine is stopped and restarted.
Electronic gearing and camming makes machine changeover completely programmable: For example, the use of FlexProfile technology lets operators load machine recipes with the touch of a button on the HMI screen, and the changes are made in the control and servo system to run the next product.
The FlexProfile camming technology makes it possible to build multisegmented cam profiles based on position, velocity, or time-based motion profiles. When you change a section of the electronic cam with a recipe change through the HMI, the control platform will automatically optimize the rest of the cam profile across all of the machine’s motion elements. This enables the machine to run a shorter cycle time, or provide smoother dynamics for the machine, even though a change has occurred such as a different bag seal time or flap tucking cam position on a cartoning machine.
Consideration #4: Incorporate energy-efficient technology
One of the fastest growing costs for any manufacturing operation is energy – and good mechatronic design can help control these costs through the application of electric drive and motor systems designed to save energy.
In machines that use servomotors directly coupled to critical axes of motion, and that also use electronic synchronization and camming, the proper sizing of the servo system can create a highly energy efficient machine.
Proper sizing requires an accurate assessment of several motion factors (motor by motor): How fast the axis needs to accelerate, the size of the mass you’re trying to move, and how precise the acceleration and deceleration needs to be. Undersizing will lead to strains on the drives and motors; oversizing will draw too much power to do too little work.
Some of today’s most cutting edge systems, such as the Rexroth IndraDrive Mi integrated drive/motor systems, include a highly energy efficient feature: bus sharing. Multiple drives are daisy-chained together and share power from the same bus; in many multi-axis machines, as some motors are accelerating up to speed (drawing power), others are decelerating (regeneration power). With bus sharing, rather than having to deliver maximum power to the accelerating motors and bleed off the decelerating motors into heat across a bleeder resister, power is shared, so the machine’s power consumption is significantly reduced.
A further energy-efficient technology is called regenerative power supplies. In many machines, multiple servomotors will decelerate at the same time, boosting the voltage to excess levels on the power bus. Older generation electrical drives would bleed that excess electrical energy as heat – wasting the power, and adding to the factory floor’s heat production, requiring additional cabinet cooling. With regenerative power supplies coupled to a shared bus system, what was once wasted power can now be fed back through the shared bus and sold back to the electric company.

The use of direct drive, direct motors and linear motors versus mechanical couplings lets you design a system to run higher gains.
Consideration #5: Use HMI’s for better troubleshooting
User-friendly intelligence is now available through today’s touchscreen HMIs. Machine layout drawings and schematics can be incorporated into control menus and diagnostic tools, to better manage the machine’s day-to-day operation and troubleshooting. Drawings and interactive instructional tools can not only show the precise point where a problem is – they can also step the operator through the tasks to restart production.
Advanced graphics like this can be combined with the distributed intelligence inherent in servomotor-driven machines, to prevent machine failures or faults before they happen. With such predictive maintenance, this capability lets you or machine designers set fault tolerance bands in drives and then monitor drive performance. Electric drives and motors allow a broad range of conditions to be monitored – conditions that are directly associated with mechanical performance; variations in load, temperature, vibration, torque, belt tightness, gear meshing are all mechanical events that generate changes in the torque profile of an electric drive and motor moving those machine elements. Mechanical engineers can set tolerance bands for these components, and if they exceed them, then predictive maintenance alerts can be clearly and intelligently displayed through the HMI to operators, along with specific advice about next steps to take to correct the issue before it becomes a serious production problem or something that can damage the machine.

With Rexroth’s IndraDrive Mi integrated motor/drive system, multiple drives are daisy-chained together and share power from the same bus, significantly reducing energy consumption.
Blending technologies for optimal value
Every electromechanical system should perform its designed function with the minimal use of energy, motion and components required to get the job done – that’s the fundamental goal of any engineer. Electrical drive and servomotor systems now offer a wealth of reliable, energy-efficient, digitally intelligent platforms to power the integrated vision of mechatronics to greater value and more innovative manufacturing and automation solutions.
Hopefully, the five considerations described here demonstrate the advantages that today’s electric drives and controls offer, helping you simplify certain mechanical design and engineering challenges and provide new resources for driving innovation and creativity in machine design.
Pendulum-Tail Robot Climbs Vertical Walls In Seconds
August 5, 2010 by admin
Filed under Robotics, Technology
Wielding two claws, a motor and a tail that swings like a grandfather clock’s pendulum, a small robot named ROCR (“rocker”) scrambles up a carpeted, 8-foot wall in just over 15 seconds – the first such robot designed to climb efficiently and move like human rock climbers or apes swinging through trees.
“While this robot eventually can be used for inspection, maintenance and surveillance, probably the greatest short-term potential is as a teaching tool or as a really cool toy,” says robot developer William Provancher, an assistant professor of mechanical engineering at the University of Utah.
His study on development of the ROCR Oscillating Climbing Robot is set for online publication this month by Transactions on Mechatronics, a journal of the Institute of Electrical and Electronics Engineers and American Society of Mechanical Engineers.
Provancher and his colleagues wrote that most climbing robots “are intended for maintenance or inspection in environments such as the exteriors of buildings, bridges or dams, storage tanks, nuclear facilities or reconnaissance within buildings.”
But until now, most climbing robots were designed not with efficiency in mind, only with a more basic goal: not falling off the wall they are climbing.
“While prior climbing robots have focused on issues such as speed, adhering to the wall, and deciding how and where to move, ROCR is the first to focus on climbing efficiently,” Provancher says.
One previous climbing robot has ascended about four times faster than ROCR, which can climb at 6.2 inches per second, but ROCR achieved 20 percent efficiency in climbing tests, “which is relatively impressive given that a car’s engine is approximately 25 percent efficient,” Provancher says.
The robot’s efficiency is defined as the ratio of work performed in the act of climbing to the electrical energy consumed by the robot, he says.
Provancher’s development, testing and study of the self-contained robot was co-authored by Mark Fehlberg, a University of Utah doctoral student in mechanical engineering, and Samuel Jensen-Segal, a former Utah master’s degree student now working as an engineer for a New Hampshire company.
The National Science Foundation and University of Utah funded the research.
ROCR is a Swinger that Claws Its Way to the Top
Other researchers have studied a variety of ways for climbing robots to stick to walls, including dry adhesives, microspines, so-called “dactyl” spines or large claws like ROCR’s, suction cups, magnets, and even a mix of dry adhesive and claws to mimic wall-climbing geckos.
Now that various methods have been tried and proven for robots to climb a variety of wall surfaces, “if you are going to have a robot with versatility and mission-life, efficiency rises to the top of the list of things to focus on,” Provancher says.
Nevertheless, “there’s a lot more work to be done” before climbing robots are in common use, he adds.
Some previous climbing robots have been large, with two to eight legs. ROCR, in contrast, is small and lightweight: only 12.2 inches wide, 18 inches long from top to bottom and weighing only 1.2 pounds.
The motor that drives the robot’s tail and a curved, girder-like stabilizer bar attach to the robot’s upper body. The upper body also has two small, steel, hook-like claws to sink into a carpeted wall as the robot climbs. Without the stabilizer, ROCR’s claws tended to move away from the wall as it climbed and it fell.
The motor drives a gear at the top of the tail, causing the tail to swing back and forth, which propels the robot upward. A battery is at the end of the tail and provides the mass that is necessary to swing the robot upward.
“ROCR alternatively grips the wall with one hand at a time and swings its tail, causing a center of gravity shift that raises its free hand, which then grips the climbing surface,” the study says. “The hands swap gripping duties and ROCR swings its tail in the opposite direction.”
ROCR is self-contained and autonomous, with a microcomputer, sensors and power electronics to execute desired tail motions to make it climb.
Provancher says that to achieve efficiency, ROCR mimics animals and machines.
“It pursues this goal of efficiency with a design that mimics efficient systems both in nature and manmade,” he says. “It mimics a gibbon swinging through the trees and a grandfather clock’s pendulum, both of which are extremely efficient.”
The study says: “The core innovations of ROCR – its energy-efficient climbing strategy and simple mechanical design – arise from observing mass shifting in human climbers and brachiative [swinging] motion in animals.”
Simulating and Testing a Climbing Robot
Before testing the robot itself, Provancher and colleagues used computer software to simulate ROCR’s climbing, using such simulation to evaluate the most efficient climbing strategies and fine-tune the robot’s physical features.
Then they conducted experiments, varying how fast and how far the robot’s tail swung, to determine how to get the robot to climb most efficiently up an 8-foot-tall piece of plywood covered with a short-nap carpet.
The robot operated fastest and most efficiently when it ran near resonance – near the robot’s natural frequency – similar to the way a grandfather clock’s pendulum swings at its natural frequency. With its tail swinging more slowly, it climbed but not as quickly or efficiently.
The researchers found it achieve the greatest efficiency – 20 percent – when the tail swung back and forth 120 degrees (or 60 degrees to each side of straight down), when the tail swung back and forth 1.125 times per seconds and when the claws were spaced 4.9 inches apart.
When the tail swung at two times per second, it was too fast and ROCR jumped off the wall, and was caught by a safety cord so it wasn’t damaged.
Provancher says the study is the first to set a benchmark for the efficiency of climbing robots against which future models may be compared. He says future work will include improving the robot’s design, integrating more complex mechanisms for gripping to walls of various sorts, such as brick and sandstone, and investigating more complex ways of controlling the robot – all aimed at improving efficiency.
“Higher climbing efficiencies will extend the battery life of a self-contained, autonomous robot and expand the variety of tasks the robot can perform,” he says.




