Abstract: The thrust T of an airplane is estimated by a thrust estimating device, and the motion state (the speed, the angular speed, the attitude angle and the elevation angle) of the airplane is detected by a motion state detecting device. Then, a drag estimating device estimates the drag D of the airplane, based on the thrust T and the motion state of the airplane. An operation-amount calculating device converges the steering angle into a target steering angle at which the drag of the airplane is minimized, by repeating the operation of varying the steering angle of a flap by a very small angle by an operating device, and further varying the steering angle by a very small angle, while monitoring the increase or decrease in drag resulting from such variation. Such a drag reducing control is carried out, while monitoring the actual drag and hence, is extremely effective, and also can exhibit an effectiveness, irrespective of the motion state of the airplane.

Abstract: A joint torque detection system having a plurality of post-like members disposed around an axis of a joint which connects two links. The plurality of post-like members deform or twist when a torque is imparted to one of the links. An electric motor is fixed at one of the links and the motor rotation is reduced by a harmonic-drive speed reducer fixed at the other of the links. The plurality of post-like members are annularly disposed around the joint axis such that they embrace the speed reducer. A gap sensor (displacement detector) is fixed to the second link, close to the speed reducer between the output of the speed reducer and the second link in such a manner that the sensor generates a signal indicative of relative displacement of the speed reducer output (connected to the one of the links) and the second link. With this arrangement, the system can be incorporated in a small link mechanism such as a robot finger link mechanism, with excellent detection accuracy and an elongated service life.

Abstract: A tactile sensor device for detecting a state of contact with a workpiece has a base body and a contact member spaced from the base body by a gap, for contacting the workpiece. The contact member is supported on the base body by a thin leaf spring for angular movement with respect to the base body and/or movement across the gap to cause a change in a distance between the contact member and the base body across the gap when the contact member is contacted by the workpiece. A gap sensor is mounted in the base body for generating a signal depending on the distance between the contact member and the base body across the gap at a predetermined region. A state of contact between the contact member and the workpiece can be detected on the basis of the distance across the gap as detected by the signal generated by the gap sensor.

Abstract: A system for controlling the locomotion of a biped walking robot having a body and a pair of legs each connected to the body through a hip joint and having a knee joint and an ankle joint and a foot at its distal end in accordance with predetermined locomotion data including a foot landing position of a lifted leg. A 6-dimensional force and torque sensor is provided at the body to detect an external force exerted on the robot. A moment is calculated from the external force and integrated during the external force exists. A coefficient is further determined in accordance with the trajectory of the lifted leg and is multiplied to the integrated moment. The predetermined foot landing position is corrected in response to the product and control values for the associated drive joints are changed such that the lifted leg will land at the corrected position, whereby preventing the robot from losing its stability when the external force exerts on the robot.

Abstract: A legged mobile robot control system for enabling the mobile robot, more particularly a biped walking robot to walk stably even over terrain with unexpected irregularities. The robot's motion is approximated by a mathematical model and a mathematical control is conducted, while controlling the robot's attitude on the basis of a walking pattern established in advance, without need to use a high-speed on board computer for non-linearlity compensation. In another embodiment made up of a more simple arrangement, when the foot angle deviates from that on flat terrain owing to the foot stepping on a bump, the foot angle is estimated and joints are driven such that the robot's center of gravity is restored in a predetermined target trajectory. In still another embodiment, the robot body's inclination angle and/or angular velocity is determined and the hip joints connecting the body with two legs are driven to restore a predetermined stable attitude.

Abstract: A system for controlling locomotion of a biped walking robot having a body and two articulated legs each connected to the body through a hip joint and having a knee joint and an ankle joint adjacent to a foot portion. The individual joints are provided with servo motors and target angle data is provided to the servo motor in time series at a predetermined interval. The actual inclination angle of the body is detected and is then compared with upper and lower limits. If the detected value is found to be out of either of the limits, a control value of the servo motor for the hip joint of the free leg lifted off of the ground is corrected in such a manner that the free leg lands forward if the robot tilts forward, for example. A control value for the supporting leg is also corrected. Moreover, the ankle joint's angle is detected with respect to the direction of gravity and the control value of the ankle joint is corrected in response to the detected value.

Abstract: A system for controlling locomotion of a biped walking robot. The system carries out feedback control for eliminating the deviation between a target value and the detected angle of inclination of the linkage mechanism in the absolute coordinate system. Hence, stable dynamic walking is achieved at all times even during locomotion over rough terrain. In the stability control, the number of joints with respect to which control is conducted is reduced to the minimum required and control is conducted separately but in coordination with respect to the movement or motion in the pitch direction and the movement or motion in the roll direction, while the remaining joints are controlled locally. Thus, the control is considerably simplified. In addition, feedback control is conducted with respect to the velocity components so as to realize the desired posture angles and the feedback gain adjusted so as to achieve the response speed required by the individual linkages.

Abstract: A system for controlling locomotion of a legged such as a biped walking robot having a body and two legs connected to the body. Positional walking data are preestablished in advance with respect to the robot's center of gravity, foot position and the like. First, a difference between the robot's center of gravity at time t (current time) and at time t+delta t (next time) defined in the walking data is calculated. From the difference, then, a positional correction amount of the robot's hip position, which is decisive for determining the robot's attitude, at the time t+delta t is determined, and the robot's attitude at the time is determined from the corrected hip position and the foot position or the like preestablished in the walking data. And based on the determined attitude at the time, target joints angles of the robot is calculated and the joints are driven to the determined target angles.

Abstract: A biped walking robot and system for controlling the robot. The system provides smooth posture control by eliminating interference arising between the frictional force of the ground acting on the legs of the robot and the driving force of the leg joints. A six-dimensional force and torque sensor is provided to detect six force or moment components and based thereon, an angular command to joint motors is corrected. A joint structure of the robot is described, wherein the axes of the drive joints are arranged at right-angles to one another to thereby enable accurate positional control to be effected using Cartesian coordinates.