1405 results about "Angular acceleration" patented technology

A device comprised of at least a pair of accelerometers and a tilt sensor mounted in fixed relation to a datum plane defining surface (sole of a shoe) may be used for extracting kinematic variables including linear and rotational acceleration, velocity and position. These variables may be resolved into a selected direction thereby permitting both relative and absolute kinematic quantities to be determined. The acceleration is determined using a small cluster of two mutually perpendicular accelerometers mounted on a shoe. Angular orientation of the foot may be determined by double integration of the foot's angular acceleration (which requires a third accelerometer substantially parallel to one of the two orthogonal accelerometers). The two orthogonal accelerations are then resolved into a net horizontal acceleration or other selected direction which may be integrated to find the foot velocity in the selected direction. The average of the foot velocity corresponds to the subject's gait speed.

Disclosed is a protective helmet and a method for mitigating or preventing a head injury, in which a shock-absorbing, or shock-absorbing and comfort-providing, inner wearing unit, which can comprise liners, comfort pads, protective pads, nubbed cages and/or strapped wearing units (for example spider-shaped wearing elements, wearing straps, head bands or the like), is divided into a shell-side insert and a head-side insert, which can be counter-rotated (preferably starting from application of a predetermined force) in at least one direction, wherein a sliding surface is provided that assumes the function of a rotational surface, so that the angular acceleration introduced by a blow is drastically reduced or prevented because the head-side insert and the shell-side insert, and thus the head of the wearer and the outer helmet shell, can be counter-rotated quickly and without impediment, preferably in all directions.

A method is disclosed for determining movement mode in a drill string. The method includes measuring lateral acceleration of the drill string, determining lateral position of the drill string from the acceleration measurements, and determining mode from the position with respect to time. Also disclosed is a method including measuring drill string acceleration along at least one direction, spectrally analyzing the acceleration, and determining existence of a particular mode from the spectral analysis. Also disclosed is a method for determining destructive torque on a BHA including measuring angular acceleration at at least one location along the BHA, and comparing the acceleration to a selected threshold. The threshold relates to a moment of inertia of components of the BHA and a maximum torque applicable to threaded connections between BHA components. A warning is generated when acceleration exceeds the threshold.

There are provided an evaluating system of a robot and its evaluating method capable of measuring a movement state amount, particularly, a position or a speed or an acceleration, or an angle or an angular speed or an angular acceleration of an arm of a robot by a simple system constitution in noncontact, accurately, in real time, dispensing with a complicated calibration. There is provided an evaluating system of a robot characterized in including a sensor provided at an arm of a robot for detecting a movement state amount of the arm, an angle detector for measuring an articulate angle of each axis servo motor of the robot, a first sensor operating portion for converting a state amount of the sensor into a state amount in a robot coordinate system, a second sensor operating portion for converting an articulate angle of the angle detector into a state amount in the robot coordinate system, and an output synthesizing portion for synthesizing an output of the first sensor operating portion and an output of the second sensor operating portion.

An apparatus for analyzing movement of equipment. The apparatus includes an inertial measurement unit continuously measuring six rigid body degrees of freedom of the equipment and outputting data representative thereof, wherein the inertial measurement unit defines a planar substrate having a single common plane. The inertial measurement unit further includes at least one angular rate gyro and at least one accelerometer sufficient to measure the six rigid body degrees of freedom and each being mounted on the single common plane. The apparatus further includes a processing unit determining the acceleration of the mass center of the equipment, the angular velocity and the angular acceleration of the equipment through a single derivative operation.

Systems and methods are provided for determining an acceleration at a location of interest within one of a user's head and neck. At least one of linear acceleration data, angular acceleration data, angular velocity data, and orientation data is produced using at least one sensing device substantially rigidly attached to an ambient-accessible surface of the user's head. The location of interest is represented relative to a position of the at least one sensing device as a time-varying function. An acceleration at the location of interest is calculated as a function of the data produced at the sensing device and the time-varying function representing the location of interest. The calculated acceleration at the location of interest is provided to at least one of the user and an observer in a human-perceptible form.

A method for estimation of relative coordinates between at least two parts of a system comprising the steps of: (A) providing each of at least two parts of the system with at least one coordinate sensor; (B) measuring a set of relevant coordinates for each part of the system; and (C) processing each measurement result performed in the step (B) to estimate the relative coordinates between at least two parts of the system. The relative coordinates are selected from the group consisting of: {relative position coordinates; relative position rate (velocity) coordinates; relative position acceleration coordinates; relative angle coordinates; relative angular rate coordinates; and relative angular acceleration coordinates}.

A measuring apparatus and method for measuring dynamic parameters in a driven bicycle wheel are described. Parameters which are measured are; driven torque, angular velocity, angular acceleration, lateral angular acceleration, and applied power of the driven wheel. The measuring apparatus is affixed to the rear driven cog(s) of a bicycle wheel. One or more strain sensing elements affixed to the rear driven cog(s) detect the applied driven torque. Three or more acceleration sensing integrated circuits are used to determine angular velocity, angular acceleration, and lateral angular acceleration of the driven rear cog. These circuits reside on the primary electronics board and are affixed to the rear driven cog; hence they rotate along with the driven rear cog. Power applied to the driven wheel is derived from the torque and angular velocity measurements of the invention. These performance variables will aid a competitive cyclist to evaluate and observe progress in his or her physical training.

A seismic exploration method and unit comprised of continuous recording, self-contained wireless seismometer units or pods. The self-contained unit may include a tilt meter, a compass and a mechanically gimbaled clock platform. Upon retrieval, seismic data recorded by the unit can be extracted and the unit can be charged, tested, re-synchronized, and operation can be re-initiated without the need to open the unit's case. The unit may include an additional geophone to mechanically vibrate the unit to gauge the degree of coupling between the unit and the earth. The unit may correct seismic data for the effects of crystal aging arising from the clock. Deployment location of the unit may be determined tracking linear and angular acceleration from an initial position. The unit may utilize multiple geophones angularly oriented to one another in order to redundantly measure seismic activity in a particular plane.

The invention discloses a trajectory tracking sliding mode control method for a spraying mobile robot. The method comprises the following steps of: performing mechanism analysis on a mobile robot, and establishing a mobile robot kinematic model with non-integrity constraint; establishing a controlled object mathematical model of each branch controller of a wheeled mobile robot provided with a motor driving shaft disturbance term; identifying a traveling path by utilizing a computer vision system, and determining an expected motion track of each branch driving motor according to the kinematic model deduced in the previous step; detecting the rotating speed of the motor, calculating the actual motion angular velocity and actual motion angular acceleration of left and right driving motors of the mobile robot, and calculating the deviation and deviation derivative between the expected angular velocity and the actual angular velocity of each driving motor; establishing a sliding mode switching function which meets the speed control requirement of the driving motor; determining the sliding mode controller control quantity of the left and right driving motors of the mobile robot on the basis of the sliding mode surface function s; and respectively transmitting the control quantity of the motor of the mobile robot to the left and right driving motors.

In a power steering device employing a hydraulic power cylinder, a motor-driven pump, and a driving power source for the motor, a power steering control system is configured to electrically connected to at least the motor and the power source for controlling a driving state of the motor and a power source voltage of the power source. The power steering control system includes a motor control circuit that generates a motor driving signal, whose command signal value is determined based on a steering assist force applied through the power cylinder to steered road wheels, a booster circuit that boosts the power source voltage, a motor angular acceleration detection circuit that detects or estimates a motor angular acceleration, and a booster-circuit control circuit that controls, responsively to the motor angular acceleration, switching between operating and non-operating states of the booster circuit.

A system and method for actively damping driveline oscillations in a motor vehicle having a traction motor to drive a vehicle's drive wheels and an antilock brake system (ABS). A traction motor controller controls a torque output signal of the motor to effectively to dampen driveline oscillations during an ABS operation. A proportional, a proportional derivative, or a derivative controller may be used to generate the torque output signal based on at least one of motor speed, an average of the drive wheel speeds, a difference in the two speeds, a motor angular acceleration, an average wheel angular acceleration, and a difference in the angular accelerations. Motor speed signals and average drive wheel speed signals may be filtered to eliminate high frequency components of each speed signal. Additionally, amplitude of the torque output signal may be limited within a positive upper and a negative lower active motor damping limit.

The invention discloses a robot compliance control method based on a contact force observer. The robot compliance control method belongs to the field of robot control, does not adopt a force sensor for measuring a contact force of a robot and the environment, but adopts a model for estimating magnitude of the force according to a motion state, and realizes compliance control of the robot by adopting a position-based impedance controller. The robot compliance control method comprises the steps of: acquiring joint angular velocity information by means of an encoder, and estimating an angle, an angular velocity and angular velocity information by means of a state observer; calculating a joint effective driving moment by means of a disturbance observer according to motor current information and joint state information; calculating a joint driving moment required by driving a mechanism to move through adopting a kinetic model according to a joint motion state; and subtracting the driving moment obtained through calculation by adopting the kinetic model from the effective driving moment to obtain a joint driving moment caused by the action of an external force, and mapping the joint driving moment by means of Jacobian matrix to obtain an environmental contact force. The robot compliance control method based on the contact force observer has the advantage that an expensive and easily-damaged multi-dimensional force sensor does not need to be installed.

The invention provides a kinematics control method for complex-curved-surface five-axis numerical control machining cutter vectors, belongs to the field of complex-curved-surface five-axis numerical control machine took precise and efficient machining, and particularly relates to a kinematics control method of cutter shaft vectors in the complex-curved-surface five-axis numerical control machining process. According to the kinematics control method of the cutter vectors, on the basis that a complex-curved-surface parametric equation is determined, the function relationship between the cutter shaft vectors and machining track curved line parameters can be established. Then, a motion parameter calculation method for a five-axis numerical control machine tool rotating feed shaft is established, so an angular velocity calculation result and an angular acceleration calculation result of the rotating feed shaft can be obtained. Finally, smoothing is carried out on the cutter shaft vectors to ensure that the rotating feed shaft of the machine tool moves smoothly and achieve the kinematics control over the cutter shaft vectors. The kinematics control method for the complex-curved-surface five-axis numerical control machining cutter vectors is wide in application scope, effectively improves machining quality of a complex curved surface, and gives better play to the performance of the machine tool.

The invention relates to a dynamic load simulating device and a dynamic load simulating method for an automobile power system test, and belongs to the technical field of vehicle power system tests. The dynamic load simulating device comprises a control computer, a dynamometer controller, a frequency converter, an alternating current (AC) power dynamometer and a torque flange with a controller. A virtual automobile model-based control algorithm is adopted, a virtual automobile model is driven by an actual measurement torque, and the simulation of the rolling resistance, wind resistance and the inertia resistance of a vehicle is realized under the conditions of not calculating angular acceleration of the dynamometer. The dynamic load simulating device and the dynamic load simulating method have high stability and high simulation precision, are favorable for shortening the development cycle of an automobile power system and providing convenient test environment for the development of the power system. A process that the vehicle acceleration is acquired by differentiating the rotation speed of the automobile power system is avoided in the calculation process, and a phenomenon that accurate differential values are difficult to acquire due to relatively large noise caused by the process of differentiating the rotation speed is prevented.

A device for measuring the dynamic matrix sensitivity of an inertia sensor is provided with a motion generating machine or a vibrating table for inducing a translational or rotary motion, an acceleration measuring unit, an angular velocity measuring unit or angular acceleration measuring unit, an output device for fetching an output from the unit, one or, pre light reflectors, a displacement measuring device for seizing a multidimensional motion by using a laser interferometer radiating light from a plurality of directions to the light reflectors, a data processing unit for processing a data indicating the state of motion and obtained from the displacement measuring unit, and a displaying device to display or a transmitting device to transmit the output of the data processing unit and the output of the acceleration measuring unit, angular velocity measuring unit or angular acceleration measuring unit. Since the accelerometer is exposed to acceleration in every conceivable direction and possibly fails to find a correct value of acceleration as encountered by the conventional one-dimensional calibration, it is actually calibrated by applying acceleration from all possible directions thereto.

The invention relates to an intelligent watchband and an operating control method thereof. The intelligent watchband is provided with a watchband main body, a watchband bracket connected with the watchband main body and a display embedded into the watchband bracket, wherein a three-axis gyroscope and a core processor are arranged on the watchband main body; the signal output end of the three-axis gyroscope is connected with the signal input end of the core processor; the three-axis gyroscope is used for detecting angular acceleration signals or angular speed signals of the intelligent watchband in X-axis, Y-axis and Z-axis directions and sending the angular acceleration signals or the angular speed signals to the core processor; the control output end of the core processor is connected with the display; the core processor is used for analyzing and processing the received angular acceleration signals or angular speed signals and sending a control command to the display so as to control on or off state of the display and switching of display interfaces. By wearing the intelligent watchband, a user only needs to rotate the wrist for achieving the operating control on the intelligent watchband, the intelligent watchband is more convenient to use, and the problem of inconvenience in use of existing intelligent wearable equipment is solved.