This paper deals with map-based localization problem. Generally, errors between an environment and a prior-map affects to the localization result. We prepare several types of map with different detailed level. Then we investigate the localization accuracy of virtual sensing image in each map type. We confirmed that the map with lower detailed level is, the worse the localization result is.

This paper summarizes the design optimization of a parallel mechanism using on human hip joint power assisting. Manipulability Inclusive Principle (MIP) evaluation criterion for evaluating assisting mechanism's assisting feasibility and assisting effect is proposed. The design of parallel assisting mechanism and building kinematical Jacobian are discussed. Moreover, as an important part of this paper, in order to finding out a architecture, which can satisfy assisting feasibility and realize higher assisting efficiency, more assisting ability and better feature on assisting isotropy, design optimization MIP is shown in this paper.

In this paper, a micro/nano displacement sensor for PZT actuator which could measure the minute displacement in micron or nanometer level has been proposed. This paper focus on the whole process of this novel sensor from the working principle, parameter determination to the FEM simulation and so forth. This sensor can enlarge the displacement of the PZT by utilizing the lever principle and the strain gauges can perceive the variation without amplifying the noise. About this sensor, we also use the flexure hinges as the rotation joints to obtain the expansion. In addition, we provide the accurate model for this special kind of displacement sensor, and through that people could design and set every parameter freely. Whatever the simulation results in FEM or the experiment data, both of which show that the sensor can perceive the displacement of the PZT actuator in micro/nano scale. Also, the characteristic experiment shows that the proposed sensor has a better performance such as higher level linearity, resolution than its former two generations.

This paper develops a 3-DOF active rotational ball joint with a simple and compact mechanism, which can realize a rotation around an any-direction rotational axis with a well manipulability and can change its direction of rotational axis smoothly and arbitrarily when it is on rotating. The mechanism principle of this joint is proposed and analyzed. Then the ball joint is developed with good dynamics and lower friction and experimental verification on the proposed mechanism is performed. The effectiveness of the mechanism principle is outlined by some experimental results.

Micro displacement measurement of the PZT actuator is a micro sensor which could measure the minute displacement in micron or nanometer level. In general, the sensor is required to accommodate little space in order to save the room of measuring device. In this paper, a mechanical micro displacement sensor with smaller volume has been proposed. This paper focus on the whole process of this novel sensor from the working principle, parameter determine to the FEM simulation as well as the characteristic experiment and so on. This sensor can enlarge the displacement of the PZT by utilizing the lever principle and the strain gauges can perceive the variation without amplifying the noise. In this sensor, we use the flexure hinges as the rotation joints to obtain the expansion. Whatever the simulation results in FEM or the experiment data, both of which show that the sensor can perceive the displacement of the PZT actuator in micro/nano scale. Also, the characteristic experiment shows that the proposed sensor has a higher level linearity, resolution and lower error.

In this paper, we develop a novel robotic arm wrestling system integrated with mechanical arm, elbow/wrist force sensors, servo motor, encoder, 3-D MEMS accelerometer, and USB camera. The arm wrestling robot (AWR) is intended to play arm wrestling game with real human on a table for entertainment. The designing scenario of the prototype model's hardware is performed. Elbow/wrist force sensors, as a crucial device in the force sensing system, are described in details. Software is developed for device driven and interface. The surface electromyographic (EMG) signals from the upper limb are sampled when a real player competes with the force testing system. By using the method of wavelet packet transformation (WPT), the high-frequency noises can be eliminated effectively and the characteristics of EMG signals can be extracted. Artificial neural network is adopted to estimate the elbow joint torque. The effectiveness of the humanoid algorithm using torque control estimated via WRT and neural network is confirmed by experiments

The use of pen as an effective communication interface to computer becomes an active research area in recent years. However, the lack of complete solutions for interchange between platforms has hampered its application as no efficient device can record the entire procedure of human handwriting behavior. In this paper, we design a force Tablet (F-Tablet) for human-computer-interaction (HCI), which can acquire the kinematics and kinetics information of human handwriting, including strokes of pen-up and pen-down, pen nib trajectory and three-axis forces of pen tip directly and simultaneously. Any stylus- and pen-like device can be used to write on it. The core part of the system, named as F-Tablet, is introduced and its ink was defined according to InkML format. An improved DTW (dynamic time warping) algorithm is also put forward to verify the online signatures based on the digital handwriting forces vector ink. The iterative experiment is introduced to decide weights for writing forces in different direction and the classification threshold

For dexterously performing object grasping and manipulation with multifingered hand of robot, sensing the fingertip forces with high-stiffness and high-sensitivity is desired. In general, from previous sensing structures, if the stiffness of a sensor is made be higher, its sensitivity is reduced. This paper proposes a novel mechanism called strain-deformation expansion mechanism for 3-axis force sensing. By the force sensing mechanism, the small strain-deformation used for force sensing can be expanded while the sensor stiffness is not reduced but is heightened. In this paper, the force sensing principle is addressed by analyzing the deformation of the sensing mechanism and the forces acting on the sensor theoretically. Then, the sensitivity of the sensing mechanism and its expansion rate of sensitivity are defined, and a design method for realizing the sensing mechanism with high sensitivity is discussed. Lastly, some experiments are performed to show the basic characteristics and the effectiveness of the sensing mechanism

External force at the end-effector is often required for the force control of robotic manipulator. In some cases, the force information measured by wrist force sensor consists of the external force and the undesired inertial force arising from the acceleration of the end-effector. Up to now, it is still difficult to extract the external force exactly for the insufficiency of acceleration information. A novel six-axis accelerometer in the type of dual annular membranes structure is presented in this paper. It can simultaneously measure all three linear acceleration components ax, ay, az and three angular acceleration components αx, αy, αz, which can be used to extract the external forces. The sensor structure and its sensing principle are described. The rated strains and interference strains obtained from Finite Element Method (FEM) simulations indicate that the accelerometer has a low level cross-sensitivity. The characteristic experiments reveal that the experimental sensitivities are in good correspondence with the results of the FEM simulations. It also shows that this accelerometer has a good linearity and minor interference errors as well as principle errors.

This paper proposes a technique that can estimate the inertia parameters of a graspless unknown object, which is pushed by robot fingers. Using the fingertip different accelerations (or angular accelerations), velocities (or angular velocities) and forces information measured in pushing operations, the algorithms to estimate the object mass (or moment of inertia) are described. Then, a line called C.M. Line, is defined in this paper. The line contains the center of mass and is between two fingertips which are in point-contact with an object side. By using two or more than two orientation-different C.M. lines, an algorithm to estimate the center of mass of the object is given. Lastly, experimental verification on the proposed approach is performed and its results are outlined.

The mechanism of the sensory-to-motor transformation as well as motor-to-sensory transformation of human beings has attracted much attention in recent years. As no efficient device can record hand intrinsic behavior, it is difficult to get its neuro-physiological models of sensory-motor coordination. In this paper, we offer a system to acquire the kinematics and kinetics information of human hand movement through handwriting. Joined with human being, an eye-brain-hand to computer (EBH-C) interaction system is presented. In this human-in-the-loop-testing system, human beings acquire image, voice or text from computer by eyes or ears then write them down. The core part of the system, named as F-Tablet/spl trade/ is able to acquire the trajectory and three-axis forces of pen-tip directly and simultaneously. With the help of this system, we designed an experiment to evaluate the handwriting movements and forces controlling ability of different ages. Some experiment results were present. Aided with conventional analysis of electroencephalography (EEG) and magnetoencephalography (MEG), the whole procedures of information transmitting, acquired by eyes and ears, processed by brain, outputted and actuated by hand, can be recorded.

There are geometric and positional uncertainties in some operations such as assembly operations. In order to perform an assembly operation by robot successfully, it is required to estimate the correct geometric and position information of a fixed environment. This paper describes a technique that can estimate the contact geometric and position information between a quadric object and a quadric environment from a number of positions and orientations of a moving object, which are measured while the object is dexterously slid and rotated on the environment around the contact position. There are six kinds of basic contact forms when the two quadric bodies are in contact with each other. Corresponding to four of these basic contact forms, four kinds of estimation approaches are proposed. By these estimation approaches, the environment geometric and position information on contacting parts can be estimated successfully. Experimental verification on the proposed approaches is performed and its results are outlined.

An underactuated robot hand with three fingers has been developed to achieve planar pinch grasp and enveloping grasp. The grasp characteristics of the underactuated hand are studied. In planar pinch grasp, which depends on two or three distal phalanges to work together, the key factors to influence grasp stability are investigated, and the sufficient and necessary conditions for stable grasp are proposed with force-closure conception. The allowed maximum external wrench is calculated when the grasp can't meet force-closure condition. In enveloping grasp, the phalanges driven by an actuator can't be controlled independently and have local motion lead to unstable grasp. Based on the definition of grasp configuration and driving force, the relationship between grasp configuration and external wrench is studied. The transition difficulty of grasp configuration is employed to evaluate the stability of enveloping grasp. Finally, some cases of stimulation are given to validate the evaluation.

/sup F/or dexterously performing object grasping and manipulation with multifingered hand of robot, sensing the finger joint torque is required. In general, the size of finger joint is quite small so that it is hard to realize the torque sensing. This paper proposes a novel mechanism, called the strain-deformation expansion mechanism, to sense the joint torque, which is small enough and fitted in the finger joint. By the torque sensing mechanism, the small joint strain-deformation used for torque sensing can be expanded without reducing the joint stiffness. In this paper, the torque sensing principle is addressed by analyzing the deformation of the sensing mechanism and the torques acting on the joint shaft theoretically. Then, the sensitivity of the sensing mechanism and its expansion rate of sensitivity are defined, and a design method for realizing the sensing mechanism with high sensitivity is discussed. Finally, some experiments with robot finger are performed to show the basic characteristics and the effectiveness of the proposed torque sensing mechanism.

In this paper, an analytical approach is proposed for planning finger positions of grasping an object with a multifingered hand. First, a method is given to obtain which combination of the object edges is possible to be used for grasping. Then, a graspable finger position region (GFPR) on a combination of edges is defined where the object can be held successfully. It is shown that the region is bounded by several boundary hyperplanes. By combining these boundary hyperplanes, two propositions for analytically and exactly obtaining the GFPR are proposed. An algorithm is proposed to find a stable GFPR that contains the biggest inscribed hypersphere of GFPR and has the largest volume. Finally, a numerical example is performed to show the effectiveness of the proposed grasp planning approach.

When multiple objects are grasped by a multifingered hand, the feasible grasp finger forces are limited directionally because of the geometrical and frictional conditions on the contact parts among the objects. This paper proposes an approach for judging if a group of given fingertip positions is feasible and obtaining the graspable finger force region. In this paper, the generable contact force set for a contact part is discussed from the geometrical and frictional conditions of the part. Based on the contact force sets for all contact parts, an algorithm to obtain the set of the internal finger forces which can be generated actually is analyzed. Then an algorithm to obtain the set of the internal finger forces which can hold all objects fast and stably is addressed. Lastly, numerical examples and their experiments are performed to verify the effectiveness of the proposed approach.

In many cases of object manipulation by robot, it is required to know the mass and center of mass of the object. For the case when the weight or shape of an object is over the grasp capacity of a robot hand, we propose a technique that can estimate the mass and center of mass of a graspless unknown object, which has curved surfaces and a base plane. A line, called the passing-CM line, which contains the center of mass is defined. For estimating the passing-CM line, a tipping operation by the robot finger which tips the object slowly and repeatedly in a parallel motion with it vertical operation plane, is proposed. Using the fingertip position and force information measured from the tipping operation, an algorithm to estimate the passing-CM line is described. Then the algorithm to estimate the mass and center of mass of the object is given by estimating the intersect point of several orientation-different passing-CM lines.

An analytical approach is proposed for obtaining finger position regions of an object with a multi-fingered hand. First, a method to obtain which combination of the object edges is possible to be used for grasping, is given. Then, a graspable finger position region on a combination of edges is defined where the object can be held successfully. It is shown that the region is bounded by plural boundary hyperplanes. By combining these boundary hyperplanes, two propositions for exactly obtaining the graspable finger position region by using an analytical method, are proposed. Finally, numerical examples are performed to show the effectiveness of the proposed approach.

In many cases of manipulating an object stably and accurately by robot, it is required to know the mass and center of mass of the object. For the case when the weight or shape of an object is over the grasp capacity of a robot hand, the paper proposes a technique that can estimate the mass and center of mass of the graspless and shape-unknown object. A plane called gravity equi-effect plane is first defined, which contains the center of mass and a contact line where the object is in line-contact with an environment. If three or over three orientation-different gravity equi-effect planes of an object are obtained, the center of mass of the object can be estimated by the intersect point of the planes. In order to estimate the gravity equi-effect plane, tip operation by robot finger, which tips the object repeatedly, is proposed. Then an algorithm to estimate the gravity equi-effect plane and an algorithm to estimate the mass and center of mass of the object are addressed by using the fingertip position and force information measured from tip operations.

When an object is grasped by a multifingered hand with power grasp, there are an infinite number of possible power grasp forms, provided by combinations of the hand shape, the contact positions between fingers and the object, and the joint torques of the hand. To plan a power grasp, it is necessary to know, by some prior evaluation which form is most suitable among these forms. This paper proposes a technique for automatically obtaining optimal power grasp. By analyzing the degree of freedom of the force space caused by frictional contacts between fingers and object, the conditions and mechanical properties of power grasp are described. Also, the region of feasible joint torques for power grasp is derived. Then, an optimal power grasp form is defined and its determination procedure is established.

In many cases of manipulating an object stably and accurately by robot, it is required to know the center of gravity and mass of the object. For the case when the weight or shape of an object is over the grasp capacity of a robot hand, the paper proposes a technique that can estimate the center of gravity and mass of the graspless and shape-unknown object. A plane called gravity equi-effect plane is first defined, which contains the center of gravity and a contact line where the object is in line-contact with an environment. If three or over three orientation-different gravity equi-effect planes of an object are obtained, the center of gravity of the object can be estimated by the intersect point of the planes. In order to estimate the gravity equi-effect plane, tip operation by a robot finger, which tips the object repeatedly, is proposed. Then an algorithm to estimate the gravity equi-effect plane and an algorithm to estimate the mass and center of gravity of the object are addressed by using the fingertip position and force information measured from tip operations.

It is well known that there are positional and geometric uncertainties in the robotic assembly operation, and that in order to perform an assembly operation by robot successfully, it is necessary to estimate the correct position and geometric information of a fixed environment. In response to these problems the authors present a technique for estimating the contact position and geometric information between the object and the environment from a number of positions and orientations of a moving object. This information is to be measured while the object is dexterously probed on the environment around the contact position. The paper considers a method for generating the probing operations automatically. First, the possibility of performing probing operations on a contact position is discussed. Then, automatic generation approaches for probing operations are described.

In assembly operations, there are various constraint states while a moving object is in contact with a fixed object. For different constraint states, the existent regions of contacting forces, geometrical constraints, possible object displacements, which can be expressed by polyhedral convex cones respectively, are different. We consider that the sizes of these regions are important characteristic of contact stability for planning assembly operations. This paper proposes an approach that can evaluate the sizes of these regions. Based on this approach, the magnitude of form constraint, the constraint maintainability and the constraint separability are defined to evaluate the contact stability and contact condition between objects. And then, their applications to planning of assembly tasks are discussed.

In this paper, two kinds of the degree of freedom in constraint state (CSDOF) are defined for motion of an object in contact with an immobile environment, and then their application to planning of assembly tasks is discussed. The CSDOF of the first kind is defined as the number of independent directions in which the object can move, keeping the current constraint state. The CSDOF of the second kind is defined as the number of independent directions in which the object can move bilaterally when it is allowed to break the current constraint conditions and to go away from the current constraint state. We discuss the difficulty of state transition by considering the two kinds of CSDOF as well as the degree of constraint in constraint state (CS-DOC) and give a criterion function for state transitions. Based on this criterion function, we propose an algorithm for planning the optimal procedure for assembly tasks. Some numerical examples are given to show the validity of the proposed approach.

Their are positional and geometric uncertainties in assembly operation. In order to perform an assembly operation by robot successfully, it is necessary to estimate the correct position and geometric information of a fixed environment. This paper describes a technique that can estimate the contact position and geometric information between the object and the environment from a number of positions and orientations of a moving object, which are measured while the object is dexterously slid and rotated on the environment around the contact position. It is assumed that the environment and object are polyhedra. There are three kinds of basic contact pairs when the two polyhedra are in contact with each other. Corresponding to these basic contact pairs, three kinds of estimation approaches are proposed. By these estimation approaches, the environment position and geometric information on contacting parts can be estimated successfully. Experimental verification on the proposed approaches is performed and its results are outlined.

The authors discuss how to manipulate an object in contact with the fixed environment with robot-fingers to perform a planned assembly operation successfully. First, the region of possible fingertip force to balance the reaction force from the environment (quasi-static analysis) is explicitly represented to ensure that the moving object is manipulated correctly. Next, by considering the assembly operation in quasi-dynamic way (i.e., assuming that the velocity of the motion is small enough to be neglected but its acceleration is not negligible), the region of feasible fingertip forces to operate the object is described. According to the region of possible finger forces, the corresponding feasible range of the fingertip positions on the object surface can be obtained. And the difference between the fingertip position obtained by the quasi-dynamic analysis and the fingertip position obtained by the quasi-static analysis is shown. Lastly, the validity of this quasi-dynamic method is verified by serval experiments., All discussions are on the assumptions that objects are polyhedra and their notions are planar and frictionless, and its velocity is small enough.

For autonomous assembly operations by a robot, it is required to build a planning function that can generate a series of operations to reach a goal state. This paper describes an automatic planning algorithm that synthesizes the assembly operation strategies. By minimizing a criterion function based on the difficulty of state transitions the method can find an optimal path in a contact state network. The degree of constraint is proposed by regarding the assembly task as a process of changing the constraint state of the object. State transition difficulty is discussed by considering the variation of the degree of constraint and the shape information from the geometric models of objects. Then, a criterion function for state transitions is defined based on the state transition difficulty. Lastly, an algorithm which plans an optimal state transition path from an initial state to a goal state is proposed. Some examples are given to show the validity of this algorithm.>