A new method to classify and describe grasping and manipulation is proposed. It is based on a combination of functions of each of the grasping surfaces composing a grasp. The description is illustrated through example grasps and manipulations by a human hand. The proposed method is useful to design robot hands when some specific desired tasks are given. The designing procedure is also illustrated with a solution to an example design problem. Since our description provides neutral expression of desired tasks in a fashion independent from specific hardware, we can expect to obtain the design of a simplified robot hand to satisfy required task conditions with a structure completely different from that of the human hand.
Considering the problem to let a robot move to a given position, we have to decide an appropriate path and control the robot so as to follow the decided path. For the former, many researches have been reported until now. But, for the latter, enough discussion has not been done. In this research, we propose a path following control strategy based on the observer based regulator using image imformation from CCD camera. Our controlled object is a two wheeled moving robot. First, we derive a state space model taking account of the dynamics of both actuators and the robot. Next, we design a controller based on the modern control theory. And we confirm the validity of our strategy via simulation and experiment.
In this paper, we propose and design Responsive Processor for parallel/distributed real-time processing, which can control various electronic control systems including robots, mechatronic systems, home automation, office automation, factory automation, etc. Responsive Processor integrates many functions into an ASIC chip, such as a RISC MPU core (SPARC), Responsive Links for real-time communication, many peripheral functions including SDRAM I/Fs, DMAC, PCI, USB, PWM generators, A/D converters, D/A converters, etc. In order to realize real-time communication needed for parallel/distributed control, a set of Responsive Link consists of a pair of two-way data links and event links. Prioritized routing which enables packets with higher priority to overtake other packets is implemented by hardware at each node. Many kinds of systems can flexibly be composed by connecting these chips using Responsive Links.
For realizing robots working in human society, interaction between people and robots is one of the important issues. We have developed a robot that behaves based on visual information and interacts with people. The robot controls its gazing direction for representing the internal states. By using the robot, we have evaluated impressions given by the robot based on psychological methods. SD method and factor analysis have been applied to evaluate the impressions. As a result of the experiments, impressions of the robot principally consisted of 4 factors: familiality, enjoyment, activity, and performance evaluation, and these have been effected by computer skills of subjects. In addition, we have verified that gazing direction control promotes interactions between people and the robot.
Force control of a tendon-driven robotic mechanism is usually done with an active compliance controller, even if the mechanism has passive compliance elements. The controller usually consists of multi feedback loops where the inner loop controls the tension forces of tendons, and the outer one controls the joint angles of the robot. For such a controller, it is assumed that the inner loop converges quickly enough so that we can ignore the dynamics of the inner loop when we design the outer feedback loop. This turns to restrict the bandwidth of the outer loop. Also it means that the stability is not proved strictly. In this paper, we show that a tendon-driven mechanism with nonlinear tendon elasticity should be controlled in the actuator level in order to utilize the performance of the compliant elements efficiently. As one of such controllers, a set-point PD controller is applied to a tendon-driven robotic mechanism to control the contact force with the environment and the Lyapunov stability is investigated. The stability analysis of a tendon-driven manipulator is rather complicated than that of a conventional manipulator or an elastic joint manipulator, because a tendon-driven manipulator has more numbers of tendons than that of the joints and the tendons have nonlinear elasticity. We derive a set of sufficient conditions for the Lyapunov stability and show some numerical simulation results.
We have proposed the 3D sway compensation trajectory of a vehicle body to realize dynamically stable walking for a quadruped walking vehicle. This method uses the 3D motion of the vehicle body to keep a zero momentum point (ZMP) on a diagonal line between the support legs, and dynamically stable walking by a trot gait is realized on a flat surface. However, for dynamically stable walking on rough terrain, feedback control of the body attitude using equipped sensors is indispensable. In this paper, we consider four stabilizing control methods, that is, a) rotation of the body along the diagonal line between the support legs, b) translation of the body along the perpendicular line between support legs, c) vertical motion of the swing legs, and d) horizontal motion of the swing legs, and compare the stabilizing efficiency for each method through computer simulation. Then, walking control that combines the 3D sway compensation trajectory and the feedback control of the body attitude using translation of the body and vertical motion of the swing legs is applied to the quadruped walking robot, TITAN-VIII, and dynamically stable walking using a generalized trot gait on rough terrain is demonstrated.
Manipulative operations of rheological objects can be found in many industrial fields such as food industry and medical product industry. Automatic operations of rheological objects are eagerly required in these fields. In this paper, deformation transition graphs are proposed for the forming operations of rheological objects. First, we will introduce a deformation transition graph so that the forming process can be described. We will then develop a method to generate a deformation transition graph through experiments. Second, a novel forming machine with multi degrees of freedom is developed for the automatic forming of rheological objects such as dough and paste. Finally, we will generate a deformation transition graph using the developed forming machine.
This paper describes a method for monitoring orientation of wheel-type or crawler-type robots in a pipe. Orientation of the robot in the pipe is important for controlling locomotion of the robots stably with dead reckoning. Basically, axes connecting left and right wheels are fixed to vehicle body. However our axes are possible to rock around the vehicle body, since the axes are freely connected to the main stem of the vehicle body at front and rear. According as the robot moves in the pipe, rocking angles of the axes are changed, and these angles are collected to know the configuration of the vehicle body. At first the structures of the robot and the free rocking mechanism are explained. Then the method for calculating the orientation utilizing rocking angles is described. Also, the optimum design of the free rocking mechanism is discussed. Finally the prototype of the robot having the monitoring function in the pipe is designed for verifying the monitoring method.
Master-slave equipment presents a force in master side by scaling up or down the force observed in slave side. For the efficiency improvement of micro operations, etc., it is desirable that the displayed force is adjusted to the human ability to perceive. In this paper, we deal with the scaling method considering the differential limen of the force, which is one of the inner force sense characteristics. By noticing the differential limen, the conditions for making it possible to perceive not only an existence but also a change of force are obtained. Under the condition that the differential limen is in proportion to standard stimulus, we show the condition for the perception of a change of force in master side. Simultaneously, lower limit of the scaling modulus for the perception is obtained. We apply the conditions to the measured results and discuss the modification of the scaling coefficient when the dispersion exists in the measured values.
We have built a biomorphic micro visual sensor equipped with a mechanical scanning system. The sensor is inspired by the structure of the fly's compound eye which was found to possess a unique muscle and tendon actuation system for its scanning retina. The improvement in micro-opto-electro-mechanical systems encourages the design of reliable, efficient and integrated smart visual sensors for robotic applications in particular for the autonomous, visually-guided navigation of mobile robots. We have verified the effect of retinal scanning for a robotic visual system through the construction of a large-scale prototype at the millimeter-scale. The performance of a newly fabricated HEMS prototype whose size approaches the order of the insects' compound eyes is then evaluated in comparison with that of the large-scale prototype. The micro-sized visual sensor is composed of a scanning microlens array (120[μm] in lens diameter) and a photo-diode array. The actuation of the microlens array induces a rotation of the visual axes. According to the principle of retinal scanning, the micro-sensor is able to retrieve the local angular velocity with enhanced reliability.