摘要:
There is disclosed a method of and apparatus for improving surface finishing and accuracy in a grinding operation employing a manipulator such as a robot which is coupled to a rotary grinding tool. The method comprises reducing the coupling effects between the tool motion whick is tangential to a workpiece surface and tool motion which is normal to the surface to obtain the optimum performance. The method involves adding compliance to the grinding tool in the tangential direction while maintaining higher stiffness in the normal direction. A robot is disclosed which is made in accordance with the method.
摘要:
An array of light sources transmit a series of light beams onto an object and the reflected light beams are focussed on a light responsive transducer. The output signals of the transducer are processed to determine the location and orientation of the object. The location and orientation information in turn is available to control the operation of a tool or manipulator relative to the object.
摘要:
Methods and apparatus for measuring arterial blood pressure at an extremity of a subject. Arterial blood pressure is derived from a circulatory measurement performed on an extremity of a subject and the circulatory measurement is normalized to account for the instantaneous vertical displacement of the extremity. The vertical displacement of the extremity relative to the heart of the subject is obtained using the angular orientation of the subject's extremity. An improved photoplethysmograph can discriminate light traversing the extremity from ambient light on the basis of differential response. The apparatus may have a conducting polymer actuator for applying pressure to the extremity of the subject. A pulsatile waveform from the photoplethysmographic signal may be obtained at a plurality of externally applied pressures to calibrate the photoplethysmograph.
摘要:
In a method and an apparatus for automatically fabricating a physical prototype, an initial prototype is created, which need not satisfy the specified performance characteristics. An initial Jacobian matrix relates changes in the prototypes design variable physical features to changes in the prototype performance characteristics. The prototype is tested to determine the error between the specifications and the prototype performance characteristics. The initial Jacobian is applied to this error to generate a change order signal for the physical features. This change signal is input to a prototyping apparatus, preferably automatic and rapid, which physically changes the prototype. The prototype is again tested for satisfaction of the specifications. If necessary, the prototype is changed again and again. The Jacobian, can be automatically changed by comparing the change in performance from one prototype to the next prototype, with the change made in physical features and applying a recursive least squares method to recursively change the Jacobian. The prototype and the Jacobian automatically converge to accurate versions of each. An apparatus includes a prototype fabrication unit, an experimentation unit, and a design feature change calculation unit, which also includes a Jacobian adjustment unit. Systematic, automatic design of complex physical structures is accomplished, without the need for a precise initial prototype or understanding of the relationship between the physical features and the performance characteristics.
摘要:
An apparatus and methods for performing a circulatory measurement on an extremity, such as a hand, of a subject. The circulatory measurement results in the derivation of an output circulatory metric that may encompass blood pressure or various other circulatory metrics. An indicator of an input circulatory metric at a locus on the extremity is measured, such as a pulse transit time. To determine the pulse transit time, a first plethysmographic signal may be obtained at a first position on the extremity, while a second plethysmographic signal may be obtained at a second position on the extremity of the subject. A transit time characterizing a circulatory pressure wave is calculated based on the first and second plethysmographic signals, leading to derivation of a wave speed. A calibration is then applied to provide the circulatory measurement based at least on the derived wave speed and a measured indicator of a hydrostatic component of blood pressure. Calibration is provided, in certain described embodiments, by derivation of two calibration parameters, a gain and a pulse transit time at zero pressure. Methods for deriving the calibration parameters include performing measurements under distinct hydrostatic pressure conditions, and based upon a measured derivative with respect to pressure of the pulse wave velocity.
摘要:
An arterial blood pressure apparatus and methods for using the apparatus are disclosed. The apparatus has a force transfer element for applying unidirectional force to a body part of the subject and a pressure sensor for generating a signal based on the unidirectional force. Multiple degrees of force may be applied simultaneously or serially. The apparatus also has a second sensor for generating a signal associated with blood volume within a blood vessel of the body part and a processor for inferring arterial blood pressure from the force sensor signal and the second sensor. The apparatus may take the form of a glove or a wand.
摘要:
The apparatus may be used with printing apparatus in which a media spreading member, such as a squeegee, moves relative to a surface, causing printing medium to be moved across said surface. The printing medium can be electrical solder paste and the surface can be a stencil. The apparatus is used for measuring linking parameters that are related to mechanical properties of the printing medium and the printing environment, such as viscosity and coefficient of friction. The apparatus comprises means for measuring a machine parameter that represents the force experienced by the media spreading member and means for resolving the measured force parameter into components equivalent to two orthogonal components, typically normal to the surface and tangential to it in the direction of relative motion. The apparatus also includes means for measuring a machine parameter that represents the velocity of the media spreading member relative to the surface. Means are also provided for measuring the linking parameters by determining a specific instance of a predetermined general relation among the measured machine parameters of velocity, first force component and second orthogonal force component and the linking parameters. The means for determining a specific instance of a relation may include means for comparing at least three sets of associated measured machine parameters and, based on the comparison, identifying a relationship that shows agreement with all of the sets of measured machine parameters within a predetermined level of accuracy. A typical such means for identifying such a relationship is an apparatus that applies a least squares relationship selecting technique. Suitable general relationships for Newtonian and non-Newtonian fluids may be used. A method is also disclosed.
摘要:
A robotic manipulator includes a plurality of segments connected by joints between a fixed base and the distal end of the arm. At least one of the joints comprises a servomotor having a stator and a rotor one of which is attached to a segment positioned closer to the fixed base, the other component of the servomotor being attached to a driven segment positioned closer to the distal end of the arm. The said mechanical arm is directly driven by the servo motor without provision of any transmission mechanism.