Kinematic and dynamic modeling of a robotic head with linear motors

Our present research focuses on kinematic and dynamic modeling of a 3-DOF robotic cutting head for the next generation of CNC machines. The robotic cutting head is one kind of parallel manipulator of 3-PUU type, which has a high flexibility of motion in three-dimensional space. The parallel manipulator consists of three linear servomotors, which drive three connecting rods independently according to the cutting strategy. Being a parallel manipulator, the robotic cutting head has higher stiffness and position accuracy; consequently, higher velocities and accelerations can be achieved. A very suitable application of this mechanism is as a cutting head of a precision machine tool for three-dimensional cutting problems.

Solution to robotic landmine detection through use of path planning and motor control

Low cost robotic detectors are a promising new approach to combat the disturbing landmine crisis. In this paper a low-cost robotic solution is proposed, we present several control techniques used to improve the precision of the robotic motion. A P and PD controller is applied, and it is concluded that a cascaded control system provides a more stable and accurate response. Two search patterns for landmine detection are considered, rectangular and spiral, these are used to analyse the effectiveness of the control system.

Automated robotic grinding by low-powered manipulator

A new robotic grinding process has been developed for a low-powered robot system using a spring balancer as a suspension system. To manipulate a robot-arm in the vertical plane, a large actuator torque is required due to the tool weight and enormous gravity effect. But the actuators of the robot system always exhibit a limited torque capacity. This paper presents a cheap and available system for precise grinding tasks by a low-powered robot system using a suspension system. For grinding operations, to achieve position and force-tracking simultaneously, this paper presents an algorithm of the hybrid position/force-tracking scheme with respect to the dynamic behavior of a spring balancer. Material Removal Rate (MRR) is developed for materials SS400 and SUS304. Simulations and experiments have been carried out to demonstrate the feasibility of the proposed system.

Bilateral haptic teleoperation of an articulated track mobile robot

Teleoperation has been used in many applications, allowing a human operator to remotely control a robotic system in order to perform a particular task. Recently haptic teleoperation has focused mainly on improving performance in remote manipulation tasks, however the haptic approach offers similar advantages for teleoperative control of the motion of a mobile robot. This paper describes a prototype system designed to facilitate haptic teleoperation of an all-terrain, articulated track mobile robot. This system utilizes a multi-modal user interface intended to improve operator immersion, reduce operator overload and improve teleoperative task performance. The system architecture facilitates implementation of an application-specific haptic augmentation algorithm in order to improve operator performance in challenging real-world tasks. The contributions of this work can be categorized as the custom mobile platform, teleoperator interface and haptic augmentation strategy.

OzBot TM - Haptic augmentation of a teleoperated robotic platform for search and rescue operations

A continued increase in computing power, sensor capability, software functionality, immersive interfaces and hardware modularity has given robot designers seemingly endless potential in the area of mobile robotics.  While some mobile robotic system designers are focusing on expensive, full-featured platforms, developers are realising the advantages of emerging technology in providing small, low-cost mobile reconnaissance vehicles as expendable teleoperated robotic systems.  The OzBot^TM mobile reconnaissance platform presents one such system.  The design objectives of the OzBot^TM platform focus on the development of inexpensive, lightweight carry-case sized robots for search and rescue operations, law enforcement scenarios and hazardous environment inspection.  The incorporation of Haptic augmentation provides the teleoperator with improved task immersion for an outdoor search and rescue scenario.  Achieved in cooperation with law enforcement agencies within Australia, this paper discusses the performance of the first four revisions of the OzBot^TM platform.

Regulation of metabolic genes in human skeletal muscle by short-term exercise and diet manipulation

Changes in dietary macronutrient intake alter muscle and blood substrate availability and are important for regulating gene expression. However, few studies have examined the effects of diet manipulation on gene expression in human skeletal muscle. The aim of this study was to quantify the extent to which altering substrate availability impacts on subsequent mRNA abundance of a subset of carbohydrate (CHO)- and fat-related genes. Seven subjects consumed either a low- (LOW; 0.7 g/kg body mass CHO) or high- (HIGH; 10 g/kg body mass CHO) CHO diet for 48 h after performing an exhaustive exercise bout to deplete muscle glycogen stores. After intervention, resting muscle and blood samples were taken. Muscle was analyzed for the gene abundances of GLUT4, glycogenin, pyruvate dehydrogenase kinase-4 (PDK-4), fatty acid translocase (FAT/CD36), carnitine palmitoyltransferase I (CPT I), hormone-sensitive lipase (HSL), β-hydroxyacyl-CoA dehydrogenase (΄β-HAD), and uncoupling binding protein-3 (UCP3), and blood samples for glucose, insulin, and free fatty acid (FFA) concentrations. Glycogen-depleting exercise and HIGH-CHO resulted in a 300% increase in muscle glycogen content (P < 0.001) relative to the LOW-CHO condition. FFA concentrations were twofold higher after LOW- vs. HIGH-CHO (P < 0.05). The exercise-diet manipulation exerted a significant effect on transcription of all carbohydrate-related genes, with an increase in GLUT4 and glycogenin mRNA abundance and a reduction in PDK-4 transcription after HIGH-CHO (all P < 0.05). FAT/CD36 (P < 0.05) and UCP3 (P < 0.01) gene transcriptions were increased following LOW-CHO. We conclude that 1) there was a rapid capacity for a short-term exercise and diet intervention to exert coordinated changes in the mRNA transcription of metabolic related genes, and 2) genes involved in glucose regulation are increased following a high-carbohydrate diet.

Dietary manipulation of muscle long-chain omega-3 and omega-6 fatty acids and sensory properties of lamb meat

The effects of dietary manipulation of muscle long-chain omega-3 fatty acids (FA) on sensory properties of cooked meat in second cross ([Merino×Border Leicester]×Poll Dorset) wether lambs were evaluated. Lambs fed dietary supplements of fish meal (FM, Exp. 1) and fish oil (FO, Exp. 2) showed moderately (P<0.01) and markedly (P<0.001) increased muscle long-chain omega-3 FA content compared with those fed the basal diet of lucerne chaff and oat chaff. Protected canola seed (PCS, Exp. 1) significantly (P<0.001) increased omega-6 FA content of the longissimus muscle. In each of the 2 experiments (1 and 2), after being fed experimental diets for 6 weeks lambs were slaughtered at a commercial abattoir. At 24 h post-mortem (PM) the semitendinosus and biceps femoris muscles were removed from animals and stored at −20°C until evaluation of sensory properties using experienced panel members. The muscle samples were stored for 3 (Exp. 1) and 12 (Exp. 2) months then removed, thawed and cooked for sensory evaluation. The meat samples were cooked under standardized conditions in a convection microwave at 180°C (20–25 min) to an internal temperature of 75°C. Cooked samples were tested for flavour, aroma, juiciness and overall palatability. The significant increase in muscle long-chain omega-3 with FM (Exp. 1 and 2) and FO (Exp. 2) or omega-6 FA with PCS (Exp. 1) were not detrimental to sensory panel evaluations of flavour or aroma of cooked meat when compared with the basal diet. However, meat from FM (Exp. 1) had lower juiciness and FO (Exp. 2) had lower overall palatability. Protected sunflower meal protein with FO (Exp. 2) significantly lowered ratings for flavour, juiciness and overall palatability. Lamb meat with increased levels of long-chain omega-3 FA can be produced without altering the sensory quality (flavour or aroma) of the cooked meat.

Comparison of the color stability and lipid oxidative stability of fresh vacuum packaged lamb muscle containing elevated omega-3 and omega-6 fatty acid levels from dietary manipulation

A series of three experiments were conducted with second cross ([Merino×Border Leicester]×Poll Dorset) wether lambs to evaluate the effects of dietary treatments on manipulation of muscle long-chain (LC) omega-3 fatty acids (FA) on the color stability and oxidative stability of fresh and vacuum packaged lamb. At the end of 7-, 6- and 6-week experimental periods for experiments (Exp.) 1–3 respectively, lambs were slaughtered at a commercial abattoir. At 24 h post-mortem, muscle longissimus lumborum (LL) and longissimus thoracis (LT) were removed and evaluated for color and lipid oxidative stability under specified commercial storage and display condition. Of the dietary supplements used, fish meal and fish oil moderately (P<0.01) and markedly (P<0.001) increased muscle omega-3 FA content, while both protected canola seed (P<0.001) and protected sunflower meal protein significantly (P<0.02) increased muscle omega-6 FA content or ratio of omega-6/omega-3 of the longissimus muscle. In all experiments, the substantial increase (P<0.001) in muscle LC omega-3 and omega-6 FA had no consistent significant effect on color values (redness (a*), yellowness (b*) and lightness (L*)) for fresh and vacuum packaged lamb over a 6-day display period. Lipid oxidation, determined by the levels of thiobarbituric acid reactive substances (TBARS) indicated the enrichment of muscle polyunsaturated fatty acid (PUFA) levels in lambs did not produce significant differences resulting either from main treatment effects or for treatment×day×type interactions (where type was fresh and vacuum packaged). Present results demonstrated the color and lipid oxidative stability of lamb longissimus muscle during refrigerated display was not affected by enhanced levels of omega-3 and omega-6 FA due to dietary treatments.

Comparison of the color stability and lipid oxidative stability of fresh and vacuum packaged lamb muscle containing elevated omega-3 and omega-6 fatty acid levels from dietary manipulation

A series of three experiments were conducted with second cross ([Merino×Border Leicester]×Poll Dorset) wether lambs to evaluate the effects of dietary treatments on manipulation of muscle long-chain (LC) omega-3 fatty acids (FA) on the color stability and oxidative stability of fresh and vacuum packaged lamb. At the end of 7-, 6- and 6-week experimental periods for experiments (Exp.) 1–3 respectively, lambs were slaughtered at a commercial abattoir. At 24 h post-mortem, muscle longissimus lumborum (LL) and longissimus thoracis (LT) were removed and evaluated for color and lipid oxidative stability under specified commercial storage and display condition. Of the dietary supplements used, fish meal and fish oil moderately (P<0.01) and markedly (P<0.001) increased muscle omega-3 FA content, while both protected canola seed (P<0.001) and protected sunflower meal protein significantly (P<0.02) increased muscle omega-6 FA content or ratio of omega-6/omega-3 of the longissimus muscle. In all experiments, the substantial increase (P<0.001) in muscle LC omega-3 and omega-6 FA had no consistent significant effect on color values (redness (a*), yellowness (b*) and lightness (L*)) for fresh and vacuum packaged lamb over a 6-day display period. Lipid oxidation, determined by the levels of thiobarbituric acid reactive substances (TBARS) indicated the enrichment of muscle polyunsaturated fatty acid (PUFA) levels in lambs did not produce significant differences resulting either from main treatment effects or for treatment×day×type interactions (where type was fresh and vacuum packaged). Present results demonstrated the color and lipid oxidative stability of lamb longissimus muscle during refrigerated display was not affected by enhanced levels of omega-3 and omega-6 FA due to dietary treatments.

Comparison of the color stability and lipid oxidative stability fo fresh and vacuum packaged lamb muscle containing elevated omega-3 and omega-6 fatty acid levels from dietary manipulation

A series of three experiments were conducted with second cross ([Merino×Border Leicester]×Poll Dorset) wether lambs to evaluate the effects of dietary treatments on manipulation of muscle long-chain (LC) omega-3 fatty acids (FA) on the color stability and oxidative stability of fresh and vacuum packaged lamb. At the end of 7-, 6- and 6-week experimental periods for experiments (Exp.) 1–3 respectively, lambs were slaughtered at a commercial abattoir. At 24 h post-mortem, muscle longissimus lumborum (LL) and longissimus thoracis (LT) were removed and evaluated for color and lipid oxidative stability under specified commercial storage and display condition. Of the dietary supplements used, fish meal and fish oil moderately (P<0.01) and markedly (P<0.001) increased muscle omega-3 FA content, while both protected canola seed (P<0.001) and protected sunflower meal protein significantly (P<0.02) increased muscle omega-6 FA content or ratio of omega-6/omega-3 of the longissimus muscle. In all experiments, the substantial increase (P<0.001) in muscle LC omega-3 and omega-6 FA had no consistent significant effect on color values (redness (a*), yellowness (b*) and lightness (L*)) for fresh and vacuum packaged lamb over a 6-day display period. Lipid oxidation, determined by the levels of thiobarbituric acid reactive substances (TBARS) indicated the enrichment of muscle polyunsaturated fatty acid (PUFA) levels in lambs did not produce significant differences resulting either from main treatment effects or for treatment×day×type interactions (where type was fresh and vacuum packaged). Present results demonstrated the color and lipid oxidative stability of lamb longissimus muscle during refrigerated display was not affected by enhanced levels of omega-3 and omega-6 FA due to dietary treatments.

Variation in maternal provisioning by lactating Antarctic fur seals: response to experimental manipulation in pup demand

An experiment involving the supplementary feeding of pups was conducted on Antarctic fur seals to investigate the factors influencing maternal foraging-attendance cycles and the differential use of nutritional resources for growth, maintenance and storage by pups. For 40% of the lactation period, male pups were given a supplement mimicking the chemical composition of Antarctic fur seal milk at a dose equivalent to 35% of the normal mass-specific milk energy intake for the species. Milk consumption, body composition and growth rates were monitored during and after the supplementary feeding period and maternal foraging-attendance cycles were monitored throughout lactation. During the supplementary feeding period, treatment pups (n=8) grew 32% faster and deposited greater adipose tissue stores than controls (n=8) but consumed the same amount of maternal-delivered milk. When supplementary feeding was stopped (timed to coincide with peak maternal milk yield in this species), treatment pups lost mass whereas control group pups continued to grow. Treatment pups weaned at a younger age (109 days) than control pups (116 days) but at the same mass (13 kg). Maternal attendance durations did not differ between the treatment and control groups throughout lactation. However, mothers of treatment pups had significantly shorter foraging trip durations (3.74 days) than mothers of control pups (4.74 days) during the period of supplementary feeding (there were no significant differences throughout the rest of lactation). These findings are in accordance with predictions of a marginal-value model of fur seal lactation behaviour.

Simultaneous state and input estimation with application to a two-link robotic system

This paper addresses the problem of estimating simultaneously the state and input of a nonlinear system with application to a two link robotic manipulator - the Pendubot. The system nonlinearity comprises a Lipschitz function with respect to the state, and a nonlinear term which is a function of both the state and input. It is shown that under some conditions, an observer can be designed to estimate simultaneously the system’s state and input. Simulation and experimental results, obtained around the inverted equilibrium position, are presented to demonstrate the validity of the approach.

Observer-based decentralized approach to robotic formation control

Control of a group of mobile robots in a formation requires not only environmental sensing but also communication among vehicles. Enlarging the size of the platoon of vehicles causes difficulties due to communications bandwidth limitations. Decentralized control may be an appropriate approach in those cases when the states of all vehicles cannot be obtained in a centralized manner. This paper presents a solution to the problem of decentralized implementation of a global state-feedback controller for N mobile robots in a formation. The proposed solution is based on the design of functional observers to estimate asymptotically the global state-feedback control signals by using the corresponding local output information and some exogenous global functions. The proposed technique is tested through simulation and experiments for the control of groups of Pinoneer-based non-holonomic mobile robots.

Towards optimization of a real-world robotic-sensor system of systems

The problem of threat detection in an unstructured environment is considered. Three systems, comprising of robots and sensors, are proposed to form a system of systems (SoS) to find a solution to the problem. System interactions are defined to provide a framework for formulation as an SoS optimization problem. Different cost and objective functions are introduced for optimization of local criteria. Using different weights, a linear combination of the local cost and objective functions is obtained to propose a global objective function. An algorithm is suggested to find an optimum value for the global objective function leading towards optimization of the SoS.