DSM, working on an SBIR project for The Office of the Secretary of Defense (OSD), is developing a new hexapod for compliance-based medical imaging and surgical interventions. The design features a six degree-of-freedom parallel end-effector mechanism that can be mounted on the end of a medium-sized robot manipulator.
DSM is actively seeking commercial opportunities for this system.
From the SBIR Project Summary: Ultrasound represents one of the most promising new technologies for use both on and off the battlefield. During ultrasound procedures, it is typically required that a specified level of force be applied on the patient, which is made particularly difficult because of the compliance of soft skin tissue and involuntary movements due to respiration. It is extremely difficult for a serial-link manipulator to respond quickly enough to accommodate this motion due to high inertia and inaccuracies caused by low stiffness at the tool point.
12 ft displacement, 1G peak acceleration, 182kg payload
System is on the path to being man-rated, with triple redundant safety scheme
Very smooth, accurate, quiet motion
Brushless linear motors and air bearings used to drive and constrain the platform
Integration of control cabinet with drivers, dynamic braking, and supplemental I/O
From "Navy Medicine Live", the official blog of Navy and Marine Corps Health Care.
"The Vertical Linear Accelerator is designed to generate precisely controlled vertical accelerations and serves as a platform for human research on such problems as vibration, spatial disorientation and motion sickness." READ MORE
An increasing number of actuation system applications require non-magnetic operation. A recent SBIR Phase I program challenged DSM to design a piezoelectric actuator with a magnetic field level below that of the earth at a distance of 1 inch. The strength of earth’s magnetic field at the surface ranges from 30-60 microteslas (300-600 milligauss). At a distance of 1 inch DSM’s FlexFrame PiezoActuator™ FPA-1200, operating at 25Hz over its full 1.2mm stroke, had a magnetic field of < 1 µT (10mG) (This is within the noise floor of the sensor.) DSM’s VF-90 electronics tested at < 2 µT (20mG) during actuator operation at a distance of 1” from its highest field part. Electronics with an even lower magnetic signature are currently in development. A custom DSM circuit, based on the HMC1053 magnetometer, was used for magnetic field sensing.
Abnormal visual-vestibular responses among aviation personnel may predispose them to spatial disorientation, loss of dynamic visual acuity, or airsickness. Past pilot referrals to the Naval Medical Research Laboratory (NAMRL) from the Naval Aerospace and Naval Operational Medicine Institutes (NAMI/NOMI) have revealed that certain pilots may be predisposed to experiencing spatial disorientation, but whose deficiencies were only detected via specialized experimental acceleration equipment and tests.
DSM’s new Vertical Linear Accelerator (VLA) was developed for NAMRL to meet two main clinical needs of the Navy: 1) to identify and transition suitable future visual-vestibular testing devices; 2) to identify and transition airsickness tests and desensitization protocols. Particular emphasis is placed on vertical linear oscillation stimuli to the otolith organs, which sense the kinds of oscillations common during challenging aviation or sea operations and which are less well understood than the semicircular canals.
The VLA system has a stroke of 12 feet (3.66m) total and the capability to reach 1 G (2g total force with gravity) acceleration and a maximum velocity of 14 ft/s. In order to maximize the value of the device to the NAMRL and the greater research community, the goal of the machine development is to make the device as smooth and as quiet as possible. This is accomplished in part by the use of brushless linear motors and air bearings as the primary mover and guidance components. The VLA will include an integrated dynamic visual acuity (DVA) tester and capability to run arbitrary waveforms. Also included is the use of a triple redundant safety scheme utilizing long travel impact bumpers, rail brakes and regenerative dynamic braking.
“The US Navy says its new vertical linear accelerator, built with government small businesses innovation research funds, is complete and being installed at Dayton. The device has a chair with a display screen that travels up and down a 3.66m-long I-beam to study vertical motion environments, for instance in helicopter research. The chair can move at rates of up to 2Hz, exerting up to 2g of force on the subject. "A lot of the research is for helicopters and then some very specific things we might want to look at," says Simmons, adding that the device could be used to study visual/vestibular interactions for any vehicles "with vertical motion" - the F-35 VSTOL variant, for example.”
DSM is a proud participant in the United States' Small Business Innovative Research (SBIR) program. As a small US based company, we are able to employ a highly specialized technical staff whose main goal is to create new technologies to solve needs of organizations of the US Government.
As a result of this activity, DSM has developed a team that can create products for you quickly based on the same design principles used for advanced technology projects.
Below are just a few videos from our more recent piezo motor projects.
DSM provides design services and support to a wide audience. Over the years we have created dozens of different prototypes. Much of of DSM's work is proprietary in nature and cannot be shared. However, we thought our readers might enjoy seeing some of the earliest and most basic DSM motor designs. The following are from the early 1990s. Enjoy.
DSM conducted four rounds of cryogenic testing on piezo-ceramic (PZT) stacks. The tests were completed as part of ongoing piezo actuation system product development efforts for DSM's Small Business Innovative Research (SBIR) programs. The test plan and results are available for purchase for $950. The PZT vendors are not identified in the report. Many PZT fabricators claim that multilayer stacks can be used at cryogenic temperatures. DSM tested multiple vendor's PZT stacks under varying cryogenic conditions. Driving the stacks with relatively high frequency oscillations appears to be particularly harmful.In order to offer piezo-actuators and piezo-motors that can operate at very low temperature, DSM has been investigating combinations of stack construction, lead attachment technique, and coating that will demonstrate reliable operation from room temperature down to cryogenic temperature.
This week DSM met a significant milestone on our SBIR Phase II "Vertical Linear Accerlerator" project.
FULL LENGTH RUN!
DSM welcomes inquiries into this developing technology and is actively seeking commercial opportunities for this system and/or expansion into additional military platforms.
PROJECT DESCRIPTION:
A Phase II SBIR from the NAVY to design and build a Vertical Linear Accelerator for Human Visual-Vestibular Acuity Testing and Training.
Main Goal: To provide vertical linear oscillation stimuli to the otolith organs, which are apparently less well understood than the semicircular canals. Motion Quality: Device must be as smooth and as quiet as possible to provide isolated stimulus to the saccule. This is accomplished in part by the use of brushless linear motors and air bearings as the primary mover and guidance components. Motion Requirements: 12ft. stroke, 2Hz freq. response, 1G peak acceleration, 182kg total payload, ± 3mm position error, arbitrary waveform capability. DVA Test: The VLA will include an integrated dynamic visual acuity (DVA) tester. Safety System: To ensure that an uncontrolled fall does not occur, a triple redundant safety scheme utilizing long travel impact bumpers, rail brakes, and dynamic braking is being implemented. Completion: DSM plans to have the VLA completed Spring 2011