Biological Insights Into Robotics: Honeybee Foraging Behavior by a Waggle Dance

A honeybee informs her nestmates of flower locations by a unique behavior called a 'waggle dance'. We regard this behavior as a good model of the 'propagation and sharing of knowledge' to maintain a society. We have attempted to reveal how this dance benefits the colony using mathematical models and computer simulation based on parameters obtained from observations of bee behavior. Our simulation indicated that the most successful forages were made by a putative bee colony that used the dance to communicate. Video analysis of worker honeybee behavior in the field showed that a bee does not dance in a single, random place in the hive, but waggles several times in one place and several times in another. The orientation and duration of waggle runs varied from run to run, within ranges of ±15° and ±15%, respectively. We also found that most of the bees that listened to the waggle dance turned away from the dancer after listening to one or two runs. These data suggest that honeybees use the waggle dance as a method of communication, but that they must base their forages on ambiguous information about the location of a food source.     

Lower Irritation Potential of Laureth‐3 Carboxylate Amino Acid Salt

Sodium laureth sulfate and amino acid type surfactants have been categorized as low‐skin irritation chemicals based on results of previous skin irritation tests. However, detergent‐induced skin irritation still occurs. Detergents with a low‐skin irritation effect are required, since the number of cosmetics for sensitive skin has increased. Therefore, an in vitro method of testing the safety of cosmetics for sensitive skin is required. Skin irritation by anionic surfactants was investigated to determine the effect of laureth‐3 carboxylate (polyoxyethylene lauryl carboxymethyl ether) amino acid salt on skin irritation. In addition, sodium laureth sulfate and amino acid type surfactants, regarded as low‐irritation surfactants, were also tested for skin irritation. The skin irritation effect of laureth‐3 carboxylate lysine salt (Surfactant 1 ), sodium laureth sulfate (Surfactant 2 ), and sodium N‐lauroyl glutamate (Surfactant 3 ) were investigated using a reconstructed human cultured epidermal model, LabCyte EPI‐MODEL24 6D. Cell viabilities of cultured epidermal cells exposed to Surfactant 1 (5.0 % aq.), Surfactant 2 , and Surfactant 3 were 82.0, 45.0 and 19.1 %, respectively. There were significant differences in cell viability upon exposure to 5.0 % aqueous test solutions of the three test chemicals. The results of the current investigation indicate that Surfactant 1 has a low skin‐irritation effect.     

Modeling and time delay control of shape memory alloy actuators

Shape memory alloy (SMA) actuators possess hard nonlinearities including backlash-like hysteresis and saturation. These nonlinearities result in steady-state error and limit-cycle problems when conventional controllers such as the proportional integral derivative (PID) are used for trajectory control. In this study, a dynamics for an SMA actuator was newly derived using the modified Liang's model. The derived dynamics showed continuity at the change of the phase transformation process, but the original model could not. SMA actuator characteristics could be well described using this dynamics. The derived dynamics could be also used effectively for the prediction of control performance and gain tuning of the time delay control (TDC). The dynamics consisted of first-order linear and second-order nonlinear equations. Accordingly, a control strategy was established for the TDC to regulate only the second-order nonlinear part for simplicity and for the internal closed loop to regulate the rest. The control strategy was examined from the point of view of influence of an antiwindup scheme and high gain tuning on control performance. An anti-windup scheme was essential to protect windup phenomenon and high gain tuning was effective when a temperature disturbance existed. In the robustness test, the TDC with high gains showed robustness to inertia variation and temperature disturbance in comparison with the TDC with low gains.     

An evolutionary algorithm for simultaneous localization and mapping (SLAM) of mobile robots

This paper presents a novel algorithm for simultaneous localization and mapping (SLAM) of mobile robots. The algorithm, termed Evolutionary SLAM, is based on an island model genetic algorithm (IGA). The IGA searches for the most probable map(s) such that the underlying robot's pose(s) provide(s) a robot with the best localization information. The correspondence problem in SLAM is solved by exploiting the property of natural selection, to support only better-performing individuals to survive. The algorithm does not follow any explicit heuristics for loop closure, rather it maintains multiple hypotheses to solve the loop-closing problem. The algorithm processes sensor data incrementally and, therefore, has the capability to work online. Experimental results in different indoor environments validate the robustness of the proposed algorithm.     

Kinematic modeling of wheeled mobile robots with slip

This work presents a kinematic modeling method for wheeled mobile robots with slip based on physical principles. First, we present the kinematic modeling of a mobile robot with no-slip considering four types of wheels: fixed, centered orientable, off-centered orientable (castor) and Swedish (also called Mecanum, Ilon or universal). Then, the dynamics of a wheeled mobile robot based on Lagrange formulation are derived and discussed. Next, a quasi-static motion is considered to obtain the kinematic conditions that provide the slip modeling equations. Several types of traction models for the slip between the wheel and the floor are indicated. In particular, for a frictional force linearly dependent on the sliding velocity, the no-slip kinematic equation of the wheeled mobile robot is related, through the weighted least-squares algorithm, with the slip modeling equations. To illustrate the applications of the proposed approach a tricycle vehicle is considered in a real situation. The experimental results obtained for the slip kinematic model are compared with the ones obtained for the well-known Kalman filter.     

Kinematic modeling and singularity of wheeled mobile robots

This paper presents a global singularity analysis for wheeled mobile robots (WMRs). First, a kinematic model of a generic wheel is obtained using a recursive kinematics formulation. This novel and efficient approach is valid for all the common types of wheels: fixed, centered orientable, off-centered orientable (caster or castor) and Swedish or Mecanum. Then, a procedure for generating robot kinematic models is presented based on the set of wheel equations and the null space concept. Next, the singularity of kinematic models is discussed: first, the kinematic singularity condition in forward models is obtained, and then the singularity condition in inverse, or even mixed, models. A generic and practical geometric approach is established to characterize the singularity of any kinematic model of any WMR with the mentioned wheels. To illustrate the applications of the proposed approach, the singular configurations for many types of WMRs are depicted. Finally, the singularity characterization is extended to include other specialized wheels: dual-wheel, dual-wheel castor, ball-type and orthogonal.     

Modeling and simulation study of an insect-like flapping-wing micro aerial vehicle

The goal of this paper is to show some of the most important features of flying insects from a control point of view, describe in details the kinematics of insects during flapping flight, establish the corresponding kinematics equations of flying insects, analyze the force and moment acting on the flying insects, and establish the corresponding aerodynamic equations. Through the kinematics equations and aerodynamic equations of flying insects, the trajectory equations and attitude equations have also been established. A detailed mathematical model of flying insects is presented in this paper, which including 3 d.o.f. of wings kinematics, i.e., flapping, lagging and feathering, and 6 d.o.f. of insects body, i.e., yaw, roll, up–down flight, left–right flight and fore–back flight. All these motions of flying insects are interrelated by the kinematics equations, attitude equations, aerodynamics model and dynamics equations of the insects' centroid. In the findal part of this paper, the mathematical simulation model of flapping-wing insects is set up and the corresponding simulation curve created.     

An active contour model with shape regulation scheme

This paper presents an active method for locating target objects in images, which is aimed at improving the performance of detecting object boundaries by enhancing the behavioral characteristics of an active contour. The proposed active contour model simulates a mechanical system consisting of two main parts: the first is a rigid fixture, called the 'core', specifying the expected shape of target boundaries, while the second is an elastic rod attached to the rigid fixture. The elastic rod deforms or moves relative to the rigid core according to the classical laws of the mechanical system. When the initial contour is applied to an image data, it is attracted near the dominant image features, but tries to keep its home shape and simultaneously make the deformation smooth if a deformation is more natural for force equilibrium. This mechanism significantly improves the performance of detecting object boundaries in the presence of some disturbing image features. The active contour is scale invariant, thereby significantly relieving the difficulty in selecting proper values for the model parameters. The values for the model parameters can be selected to make the contour have the desired behaviors around the equilibrium position through the analysis of the vibration mode of the mechanical system. The performance of the proposed method is validated through a series of experiments, which include detection of heavily degraded objects, tracking of objects under non-rigid motion and comparisons with the original snake models.     

Adaptive dynamic walking of a quadruped robot using a neural system model

We are trying to induce a quadruped robot to walk dynamically on irregular terrain by using a neural system model. In this paper, we integrate several reflexes, such as a stretch reflex, a vestibulospinal reflex and extensor/flexor reflexes, into a central pattern generator (CPG). We try to realize adaptive walking up and down a slope of 12°, walking over an obstacle 3 cm in height, and walking on terrain undulation consisting of bumps 3 cm in height with fixed parameters of CPGs and reflexes. The success in walking on such irregular terrain in spite of stumbling and landing on obstacles shows that the control method using a neural system model proposed in this study has the ability for autonomous adaptation to unknown irregular terrain. In order to clarify the role of a CPG, we investigate the relation between parameters of a CPG and the mechanical system by simulations and experiments. CPGs can generate stable walking suitable for the mechanical system by receiving inhibitory input as sensory feedback and generate adaptive walking on irregular terrain by receiving excitatory input as sensory feedback. MPEG footage of these experiments can be seen at: http://www.kimura.is.uec.ac.jp.     

Image-based predictive display for high d.o.f. uncalibrated tele-manipulation using affine and intensity subspace models

The addition of immediate but estimated visual feedback, called predictive display, improves tele-manipulaton performance when the real video feedback is delayed. Current systems typically rely upon a previously calibrated camera and manipulator. We present a method where the motor-visual calibration is estimated on-line from motor commands and returned video images only. Predicted visual feedback is presented in two forms. As soon as a basic model has been estimated, a wire frame drawing of the predicted current pose is overlaid on the delayed video feedback. After some time when a rich model has been estimated, predicted intensity images are synthesized and these replace the delayed real video. In an intermediate situation where blurry synthesized images can be computed, the wireframe is overlaid on the synthesized images to show precisely the pose of the object. Experiments with a Utah/MIT robot hand and PUMA robot arm are shown.