A tutorial account of variable structure control with sliding mode is presented. The purpose is to introduce in a concise manner the fundamental theory, main results, and practical applications of this powerful control system design approach. This approach is particularly attractive for the control of nonlinear systems. Prominent characteristics such as invariance, robustness, order reduction, and control chattering are discussed in detail. Methods for coping with chattering are presented. Both linear and nonlinear systems are considered. Future research areas are suggested and an extensive list of references is included. >

Variable structure control: a survey

This book, written by two major figures in adaptive control, provides a wealth of material for researchers, practitioners, and students. While some researchers in adaptive control may note the absence of a particular topic, the book‘s scope represents a high-gain instrument. It can be used by designers of control systems to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs. The book is strongly recommended to anyone interested in adaptive control.

Adaptive Control

The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous measurement of glucose in a host.

Transcutaneous analyte sensor

Chatter suppression techniques in metal cutting

An apparatus includes a housing, a medicament container, an actuator, and a biasing member. The actuator is configured to move the medicament container within the housing when the actuator is moved from a first configuration to a second configuration. The actuator includes a gas container and a puncturer. When the actuator is in the first configuration, a portion of the puncturer is disposed apart from the gas container. When the actuator is in the second configuration, the portion of the puncturer is disposed within the gas container. The gas container has a longitudinal axis offset from a longitudinal axis of the medicament container. The biasing member is configured to bias the actuator toward the second configuration.

Devices, systems, and methods for medicament delivery

It is a well-known fact that, in general, many students have a lack of interest and proficiency in mathematics and science. Therefore, it is imperative that we prepare and inspire all students, specifically students of underrepresented populations, to learn science, technology, engineering, and mathematics (STEM) content. Now in its fourth year, See Blue STEM Camp was created in order to expose middle-level students to a variety of STEM fields and STEM professionals through hands-on project-based learning experiences in order to increase their interest in STEM. This paper describes the structure and the activities of the camp. In this innovative project, we utilized an embedded mixed methods study design to investigate the extent middle level students' attitudes, perceptions, and interest in and toward STEM fields and careers changed after participating in an informal learning environment of a five-day day camp held on the campus of a major university in the mid-south. The results revealed an increase in their motivation and interest in STEM fields; in fact, there was 3% increase from pre to post in interest in STEM careers. The data also revealed that a majority of the participating middle school students found the STEM content sessions “fun” and engaging, specifically citing the hands-on experiences they received.

Developing Middle School Students' Interests in STEM via Summer Learning Experiences: See Blue STEM Camp

An apparatus and method for the self-administration of a plurality of doses of an intranasal liquid pharmaceutical composition, including opioid analgesics, that includes a drug delivery device containing a plurality of sealed vials, each vial containing a predetermined volume of the pharmaceutical composition, a pump assembly for conveying the liquid pharmaceutical composition from the interior of the vial and discharging it as a nasal spray in response to manual activation by the patient, and programmable means for sequentially advancing a vial to the ready position after passage of a prescribed time interval following the last activation of the delivery device.

/pdf/programmable-multi-dose-intranasal-drug-delivery-device-1hta8tjvfx.pdf

Programmable multi-dose intranasal drug delivery device

In this paper, the use of an active dynamic absorber to suppress machine tool chatter in a boring bar is studied. The vibrations of the system are reduced by moving an absorber mass using an active device such as an piezoelectric actuator, to generate an inertial force that counteracts the disturbance acting on the main system. An equivalent lumped mass model of a boring bar with active dynamic absorber is considered. A cutting process model that considers the dynamic variation of shear and friction angle, that causes self-excited chatter during the cutting process, is applied to the lumped mass model. The theory of regenerative chatter is also applied to the model. Stability boundaries have been calculated for maximum permissible width of cut as a function of cutting speed. A comparison of the boundaries for chatter-free cutting operation of a plain boring bar, a boring bar with passive tuned dynamic absorber and a boring bar with active dynamic absorber is provided in this paper. The comparison shows that a substantial increase in the maximum permissible width of cut for stable cutting operation, over a range of cutting speeds, is obtained for a boring bar equipped with an active dynamic absorber.

A study of cutting process stability of a boring bar with active dynamic absorber

Many studies have been conducted into the control of weld joint penetration utilizing a weld-face sensor. In this paper, a weld-face vision-based strategy is presented. The strategy employs a structured-light three-dimensional vision sensor to measure the weld-face geometric parameters of the cross-section of full joint penetration welds in real-time. The principle behind this strategy depends on the relationship between the root surface weld width and the measured weld-face parameters

Determining joint penetration in GTAW with vision sensing of weld face geometry

An active vibration control device for controlling vibration in a cantilevered member (12) and a method for the same are disclosed. The device is comprised of a cantilevered member (12) having a longitudinal axis (13) comprising a sensor (92) mounted near the free end of the member (12) to measure motion of the member (12) in a transverse direction and to produce a corresponding signal. A force generating assembly (64) is mounted to the member (12) near the free end to oppose the measured motion with a force thereby minimizing subsequent motion along the transverse axis caused by vibration.

/pdf/active-vibration-control-device-4xw92nalnm.pdf

Bruce L. Walcott

Papers

Developing Middle School Students' Interests in STEM via Summer Learning Experiences: See Blue STEM Camp

Programmable multi-dose intranasal drug delivery device

A study of cutting process stability of a boring bar with active dynamic absorber

Determining joint penetration in GTAW with vision sensing of weld face geometry

Active vibration control device