Abstract: A method for determining motor velocity includes receiving motor sensor data from at least one motor sensor associated with an electric motor, the motor sensor data including a plurality of motor sensor measurements and respective time values; determining an average time value based on the respective time values for each motor sensor measurement; generating a first gain value, a second gain value, and a third gain value, the first gain value being generated based on at least the average time value; and estimating a motor velocity based on at least one motor sensor measurement, the average time value, the first gain value, the second gain value, the third gain value, and at least one previously estimated motor velocity.

Abstract: A networking hardware system includes a housing; a board located in the housing and comprising a plurality of components; a liquid cooled heat exchanger; and one or more fans disposed near the liquid cooled heat exchanger and configured to provide cool airflow from the liquid cooled heat exchanger to any of the plurality of components. The housing can be substantially sealed from an external environment and includes no air intake thereon, removing a need for higher powered fans and for air filtering for dust. The housing can include a faceplate with no air intake thereon, providing increased density for ports on the faceplate.

Abstract: Embodiments described herein provide systems and methods for preventing and mitigating collisions between components of an industrial machine. The industrial machine includes an electronic controller, having an electronic processor and a memory, that is configured to receive dipper position data indicative of a position of the dipper and determine a distance between the dipper and tracks of the industrial machine based on the dipper position data. The electronic controller is further configured to set a motion command limit for a dipper motion based on the distance, the dipper motion being selected from a group of a swing motion, a crowd motion, and a hoist motion and control the dipper motion according to a dipper motion command limited by the motion command limit.

Abstract: Disclosed is a system comprising: a plant (P) to be controlled; a controller (C); a first weight function (W1); a second weight function (W2); and a disturbance observer, wherein the first weight function (W1) receives a difference value between a disturbance (w) and an output (uDO) of the disturbance observer as an input value, the second weight function (W2) receives a difference value between the output value of the controller (C) and the output (uDO) of the disturbance observer as an input value, the plant (P) to be controlled receives, as an input value, the sum value of the disturbance (w) and the difference value between the output value of the controller (C) and the output (uDO) of the disturbance observer, and the controller (C) receives an output value of the plant (P) to be controlled as an input value.

Abstract: A multi-pump control system with a control module, a processing module, communication interface, and a storage module. The system is configured to change a number n of running pumps, and receive a signal indicative of a power consumption P and information about a speed ? of one of the n running pumps before and after two different changes of the number n of running pumps. The system is configured to determine, before and after at least two different changes of the number n of running pumps, without a measurement of a differential pressure ?p and of a flow Q, two approximated pump characteristics Pn and ?{tilde over (p)}n, wherein each of the approximated pump characteristics Pn and ?{tilde over (p)}n is unambiguously defined by a pair of parameters (?1, ?2; ?3, ?4). The system is configured to store the pair of parameters (?1, ?2; ?3, ?4) for each of the determined approximated pump characteristics Pn and ?{tilde over (p)}n.

Abstract: A motor controller comprises a switch circuit, a control unit, and a duty cycle processing unit. The switch circuit is coupled to a motor for driving the motor. The control unit is configured to generate a plurality of control signals to control the switch circuit. The duty cycle processing unit receives a first pulse width modulation signal, where the first pulse width modulation has a first duty cycle. The duty cycle processing unit is configured to judge if the first duty cycle is equal to 0% or 100%. The duty cycle processing unit comprises a duty cycle computing unit, where the duty cycle computing unit is configured to capture the first duty cycle.

Abstract: Systems and methods disclosed relate to autonomous vehicle technology. A follow vehicle having driving controls for use by humans may be equipped with a wireless transceiver, controller, sensors, and interfaces for use with control systems such that the follow vehicle may be caused to follow the lead vehicle without human interaction with the follow vehicle. The follow vehicle may wirelessly receive information from the lead vehicle regarding position, movement, acceleration or deceleration, steering, or other information relevant to following the lead vehicle. The follow vehicle may include sensors for sensing the position, movement, acceleration, deceleration, steering, or other properties of the lead vehicle. The lead vehicle may be equipped with RF transmitters that provide indicators to the follow vehicle, such that the sensors can more readily sense the lead vehicle. Multiple follow vehicles may be wirelessly linked to form a train that is not mechanically linked.

Abstract: An image processing apparatus capable of preventing display priority of an application button displayed on a home screen from being raised to a higher rank due to repeat of error termination. A plurality of application buttons each for executing a predetermined job with settings therefor are displayed on the home screen. A user interface selects one object of the plurality of objects. After the one object is selected by the user interface, the one job is executed based on settings set in association therewith. When execution of the job is not normally completed, the controller does not increase the number of times of use of the object selected by the user interface according to which the display priority of the object is raised.

Abstract: An automated system for a machine can include a controller and a plurality of position sensors to deliver information regarding a position of a work tool of the machine to the controller; wherein the controller receives information regarding a location of a machine structure of the machine, and wherein the controller is configured to establish a first virtual boundary proximate to the machine structure in view of the information regarding the location of the machine structure; wherein the controller is configured to receive operator commands regarding one or more functions of the work tool of the machine; and wherein, when the work tool reaches the first virtual boundary, the controller inhibits one or more functions of the work tool while at the same time allowing other functions of the work tool.

Abstract: A non-transitory computer-readable medium storing instructions, the instructions, when executed by a processor, cause the processor to: perform a follow-up steering control for changing a steering angle of a vehicle in such a manner that the vehicle travels along a target traveling line determined based on a preceding vehicle trajectory, which is a travel trajectory of a preceding vehicle traveling ahead of the vehicle; and when a first distance condition and a manual steering condition are both satisfied while the follow-up steering control is being performed, stop the follow-up steering control, the first distance condition being a condition satisfied when a deviation distance in a road-width direction between the preceding vehicle trajectory and the vehicle is equal to or longer than a predetermined first threshold, and the manual steering condition being a condition satisfied when a driver operates a steering wheel to change a position in the road-width direction.

Abstract: A control device for controlling a brake of a vehicle includes an arbitrating unit configured to receive motion requests for a plurality of actuators, which are used for controlling a motion of the vehicle, from a plurality of application requesting units related to driving support functions and to arbitrate the received motion requests, a command distributing unit configured to distribute commands to controllers for controlling the actuators based on an arbitration result obtained by the arbitrating unit, and a feedback controller configured to feed back a control record value indicating the motion of the vehicle, which is measured by using sensor units, to the application requesting units and to realize the motion of the vehicle requested by the application requesting units.

Abstract: In simulating a behavior of a particle system including a plurality of particles disposed in an analysis region, by using a molecular dynamics method, centroid velocities of the particles present in a local region including a particle of interest are converted on the basis of the number of particles present in the local region for each of the particles, and thus a conversion value of a centroid velocity of the local region is calculated. Temperature control of maintaining the temperature of the particle system to be a target temperature is performed by using a difference between a velocity of the particle and the conversion value of the centroid velocity of the local region including the particle as a velocity of the particle which is a basis for calculating the temperature of the particle system.

Abstract: A longitudinal driver assistance system in a motor vehicle includes a detection system for recognizing upcoming relevant events which require a change in the maximum permitted top speed, and a functional unit which, upon recognizing a relevant event, determines a location-dependent time taking into consideration the location of the relevant event. Upon achieving this, the functional unit prompts the transmission of request information for permitting an automatic adaptation of the current maximum permitted top speed to a new maximum permitted top speed. With the determining of the location-dependent time, the functional unit is also configured to take into consideration a predetermined minimum duration for the transmission of the request information.

Abstract: A method of estimating a motor velocity in an electric power steering system that includes a motor is provided. The method generates motor position data by sampling an original motor position signal at an irregular sampling rate. The method estimates a motor velocity by performing a regression analysis on the motor position data.

Abstract: A method for identifying a longitudinal jerking of a motor vehicle is provided, wherein a wheel speed of a driven wheel and a wheel speed of a non-driven wheel are recorded and wherein the longitudinal jerking of the motor vehicle is detected on the basis of a change in the measured wheel speeds. The detection of the longitudinal jerking is improved by comparing the change in the wheel speed of the driven wheel with the change in the wheel speed of the non-driven wheel in order to detect a longitudinal jerking as a result of a vibration stimulation in the drive train.

Abstract: Various embodiments include a system having: at least one computing device configured to tune a set of gas turbines (GTs) by performing actions including: commanding each GT in the set of GTs to a base load level, based upon a measured ambient condition for each GT; commanding each GT in the set of GTs to adjust a respective output to match a nominal mega-watt power output value, and subsequently measuring an actual emissions value for each GT; adjusting an operating condition of each GT in the set of GTs based upon a difference between the respective measured actual emissions value and a nominal emissions value at the ambient condition; and further adjusting an operating condition of each GT in the set of GTs based upon a determined emissions measurement error.

Abstract: A method, computer system, and computer readable medium for defining boundaries of a selection range for a variable speed device, the variable speed device being dependent on at least a first parameter and a second parameter, the first parameter and the second parameter being correlated. The method includes: determining a first boundary of the selection range defined by a reference to an efficiency curve of the variable speed device, determining a second boundary of the selection range based on a percentage of the efficiency curve, adjusting the first boundary or the second boundary based on a cost dependent on at least an operating cost of the variable speed device operating at part loads for a specified period of time, and displaying on a graphical interface screen a graph of the first parameter versus the second parameter, the graph having displayed thereon a region representing the selection range.

Abstract: The vehicle-use speed control apparatus sets a virtual preceding vehicle assumed to run at a target speed at a predetermined initial distance ahead of the own vehicle when the brake pedal is operated causing a relative speed between the actual vehicle speed and the target speed exceeds a predetermined value, calculates an initial value of a performance index for approach and alienation based on the initial distance and the target speed. Thereafter, the vehicle-use speed control apparatus repeatedly calculates a following distance to the virtual preceding vehicle based on a time elapsed from when a speed control start condition is satisfied, the current relative speed and the initial distance, and a target relative speed based on the initial distance, the initial value of the performance index and the following distance, and controls the vehicle speed based on the difference between the target relative speed and the actual relative speed.

Abstract: A system is provided to correlate a medication package with a prescribed medication for a patient. The medication package accommodates an intended patient medication. The system includes an optical imager adapted to read an encoded symbol character comprising encoded patient information and further adapted to image an attribute of the medication package. The optical imager comprises a two-dimensional image sensor array and an imaging lens for focusing an image on the two-dimensional image sensor array. The two-dimensional image sensor array has a plurality of pixels formed in a plurality of rows and columns of pixels. The optical imager further includes a digital link to transmit a segment of data. The segment of data includes the patient information encoded in the encoded symbol character and the attribute of the medication package.

Abstract: An airflow managing system for monitoring airflow of a HVAC system, a HVAC system and a method of monitoring the airflow in a HVAC system is provided. In one embodiment, the airflow managing system includes: (1) an air pressure sensor configured to obtain an air pressure measurement directly from a scroll of an air blower of the HVAC system and (2) a HVAC controller configured to determine an airflow rate for the HVAC system based on the air pressure measurement and corresponding parameters associated with the air blower.

Abstract: The so-called “wagon wheel effect”, which our apparatus produces and measures under specific conditions which we have designed, appears when the visual superposition of (elements of) disks in motion, observed with one or two eyes, reaches a speed, at which normal brain processes perceive as a rotation speed inversion. We present an apparatus and a method allowing for various parameters measuring various conditions to be considered (such as rotation speed, lightning intensity, disk patterns variable in colors, in sizes, in symmetry and in their ability to reflect light—matt or glossy) to support the establishment of a normative theory and measure specific populations (aging population, individuals suffering from mental illness such as Alzheimer, possibly in their early stage of development) against this norm.

Abstract: A drive control system for a moving device such as a vehicle uses a dynamic force vector program that is hosted by a computer on the vehicle. Variable controllers receive input from the computer that automatically adjusts drive and slave motors which in turn propel an associated drive member so as to maximize efficiency of the operation of the vehicle in various terrain conditions. Sensing devices provide continuous load and condition parameters to the computer that in turn adjusts the torque outputs for the variable controllers which in turn dynamically adjusts the vehicle's operation based on current operating conditions.

Abstract: A convey control device for a long object includes an upstream side conveying unit, a buffer unit, a downstream side conveying unit, and a convey control unit. When starting to convey the long object, by a catalyst of starting output of conveying speed information of the long object output after receiving a convey start instruction sent from another device following the downstream side conveying unit, the convey control unit releases the restricting of a driving source of the upstream side conveying unit and the downstream side conveying unit and starts the convey control of the long object.

Abstract: Disclosed is an apparatus, system, and method for sensing the current supplied to a motorized hoist for raising a maintenance platform and providing an estimate of the operating status of the motor, for example, as stopped, starting, stalled or operating as expected. In various embodiments, measures of voltage and current may be used to determine the operating condition of the hoist and to estimate the magnitude of the applied load. Unintended modes of operation can then be determined so that the conditions can be indicated to the operator and protective measures taken.

Abstract: A method for testing rotation speed of a fan receives a duty cycle ratio related to the fan sent from a dial switch on a test board connected to the fan. The method transmits a pulse width modulation (PWM) signal based on the duty cycle to the fan to power rotation of the fan, then detects the PWM signal transmitted to the fan and a tachometer (TACH) signal transmitted from the fan. The method gathers the duty cycle ratio related to the fan from the PWM signal and an actual rotation speed of the fan from the TACH signal, and displays the duty cycle ratio and the actual rotation speed together on the test board.

Abstract: A system is provided to correlate a medication package with a prescribed medication for a patient. The medication package accommodates an intended patient medication. The system includes an optical imager adapted to read an encoded symbol character comprising encoded patient information and further adapted to image an attribute of the medication package. The optical imager comprises a two-dimensional image sensor array and an imaging lens for focusing an image on the two-dimensional image sensor array. The two-dimensional image sensor array has a plurality of pixels formed in a plurality of rows and columns of pixels. The optical imager further includes a digital link to transmit a segment of data. The segment of data includes the patient information encoded in the encoded symbol character and the attribute of the medication package.

Abstract: Example embodiments disclosed herein relate to identifying a target fan connected to a computing device. In example embodiments, the target fan may be identified based on a fan speed profile of the target fan.

Abstract: A computer and a control method for smart fan thereof are provided, wherein the computer includes a processor configured to control a smart fan under an UETFI bios mode. A sensed temperature value from a temperature sensor, and a current speed value of the smart fan are acquired. A real-time temperature curve and a real-time speed curve are traced in a dynamic updating zone of a graphical interface respectively according to the current temperature and the current speed value. A first control point and a second control point, which correspond to the smart fan, are obtained via a control zone of the graphical interface. A control curve is traced in the graphical interface according to the first and second control points. The speed of the smart fan is controlled according to the control curve.

Abstract: A method of controlling a transition time through a speed range that is unsafe for an integrity of a second expander that receives a fluid flow from a first expander, by automatically biasing a speed of the second expander is provided. The method includes setting the speed of the second expander to be smaller than a current speed of the first expander. The method also includes setting the speed of the second expander to be larger than the current speed of the first expander, when the current speed of the first expander is within the bias application range, and the current speed of the second expander increases and is larger than the first speed value, or decreases and is larger than the second speed value.

Abstract: A method of decreasing a transition time through a speed range that is unsafe for an integrity of a first expander, by automatically biasing a speed of a second expander that receives a fluid flow output from the first expander is provided, when the current speed of the first expander is within a bias application range. The method includes setting the speed of the second expander to be larger than a current speed of the first expander when the current speed of the first expander increases and is smaller than a first speed value, or decreases and is smaller than a second speed value, and setting the speed of the second expander to be smaller than the current speed of the first expander, when the current speed of the first expander increases and is larger than the first speed value or decreases and is larger than the second speed value.

Abstract: A speed limiter method and system that automatically limits the maximum speed of a motor vehicle based on the segment of the road the vehicle is travelling on and on the user or driver of the vehicle, by modifying an actual throttle sensor signal from the throttle position sensor of the vehicle transmitted to the engine control unit.

Abstract: A fan system includes a pulse signal generation portion and a plurality of fans. Each of the plurality of fans preferably includes a motor portion; an impeller arranged to be rotated by the motor portion; a drive circuit arranged to drive the motor portion; a rotation detection portion arranged to detect rotation of the motor portion; and a rotation rate control circuit arranged to, based on a reference pulse signal supplied from the pulse signal generation portion and an actual rotation pulse signal supplied from the rotation detection portion, exercise feedback control on a rotation rate of the motor portion in accordance with a period of the reference pulse signal.

Abstract: A method for controlling speed of a vehicle based upon control messages received through a communications device within the vehicle includes monitoring communication of control messages to a propulsion controller wherein control messages includes a speed profile including a current speed command representing instantaneous desired speed of the vehicle and future speed commands representing a predetermined controlled vehicle stop through a speed profile period, detecting anomalous communications of the control messages, and controlling the speed of the vehicle during anomalous communications using the future speed commands.

Abstract: A system for arranging and operating an array of wind machines to protect crops from damaging weather conditions, such as freezing frost, rain and heat. The method includes a wind machine positioned to force air across the crop. The wind machine is preferably a propeller/tower configuration. The operational method of the wind machine array includes the steps of sensing ambient meteorological and the hardiness of the crop to withstand a particular adverse weather condition and operating the wind machines in response to these factors. Multiples of wind machines are employed in the preferred embodiment of the method, the siting of the wind machines preferably based upon topographic and historical meteorological conditions. The operation of the wind machines can be automatically and remotely operated with the aid of satellite communications including internet links.

Abstract: An electronic device and a method for controlling fan speed of the electronic device include setting a speed range corresponding to a variety of pulse-width modulation (PWM) duty cycles of the fan, and setting a speed variation value of the fan. The method further includes reading the PWM duty cycle and detecting an actual speed of the fan, and adjusting the PWM duty cycle in the PWM duty cycle instruction according to the speed variation value.

Abstract: A demagnetization detection device and a demagnetization detection method thereof are provided. The demagnetization detection device is for use in a power control unit which is electrically connected to a testing permanent magnet motor. The power control unit is electrically connected to a direct current power source. The demagnetization detection device is configured to detect a testing voltage value and a testing current value of the direct current power source, and to compute a testing power value of the direct current power source according to the testing voltage value and the testing current value. The demagnetization detection device determines the difference between the testing power value and a standard power value, and then determines whether the testing permanent magnet motor is in a demagnetization status according to the difference.

Abstract: A device calculates a first air speed representing an estimated air speed during flight using measurements of static pressure and total pressure onboard the aircraft. The device includes a storage device for storing in memory, in case of detection of a ground taxiing of the aircraft, the most recently determined value of static pressure corrected from induced aerodynamic effects. As a result, a second air speed representing the estimated air speed during the ground taxiing may be calculated by implementing a correction and using the most recently determined value of static pressure when the ground taxiing of the aircraft is detected. A method for automatically estimating an air speed of an aircraft is also provided.

Abstract: A method and a valve arrangement are provided for electronic wear state determination of the valve arrangement for controlling a process medium flow. A valve element, which is arranged so as to move axially within a valve housing, is moved via electrically drivable linear drive means on the basis of positioning regulation. The valve element has an essentially constant drive force applied to it, and a position speed profile over the switching travel of the valve element is determined by detecting the speed as a function of the current position of the valve element. A change profile is created by comparing the determined speed profile with previous position speed profiles, as a measure of the position-dependent wear state of the valve mechanism.

Abstract: The disclosed windfarm control system comprising a windfarm and a central controller; the windfarm including plural wind power generators whose rotational speeds are variable, plural aerographs disposed in the vicinity of the wind power generators to measure the directions and powers of the wind at the sites of the generators, and plural local controllers disposed in the vicinity of the wind power generators to control the output of the wind power generators by controlling the rotational speeds of the generators; wherein the central controller calculats the control level which maintains the output of the windfarm constant for a predetermined time period and instructs the local controllers to control the rpm's of the wind power generators in accordance with the control level.

Abstract: A storage apparatus includes: a storage drive providing a physical storage area for creating a logical storage area used by an external apparatus; a storage controller including a plurality of central processing units (CPUs) executing data write processing from the external apparatus to the storage drive, and data read processing from the storage drive; a plurality of cooling fans cooling the storage drive; a temperature sensor detecting a temperature of air introduced or discharged by the cooling fans; and a revolving speed sensor detecting a revolving speed of each cooling fan. Any of the CPUs executes operation control processing in which, through a data network path to the storage drive for the data write and read processing, measurement values of the temperature and revolving speed sensors are acquired and a revolving speed setup value of the fans is calculated and is transmitted to the cooling fans.

Abstract: A method generates trajectories for motor controlled actuators subject to dynamics, acceleration and velocity constraints. The method solves a constrained optimal control problem with dynamics, acceleration, and velocity constraints. The motor control problem is formulated as an optimal control problem using an energy cost function which is based on numerical optimization results. A solution to the two-point boundary value problem (TBVP) for the unconstrained case of the optimal control problem is obtained. The energy efficient motor control trajectory generation solver is designed for real time energy efficient trajectory generation. The solver converts a difficult multi-point boundary value problem (MBVP) associated with the state and acceleration constrained optimal control problem into an iterative solution for the TBVPs with updated boundary conditions.

Abstract: A printing apparatus is controlled to generate a pulse signal so that a print medium conveyance speed detected by an encoder comes close to a target speed. The duty of the generated pulse signal is calculated every predetermined timing. When a sensor detects the leading end of the print medium, the duty of the pulse signal input to a feed motor is stored in a memory. It is determined whether the difference between the calculated duty and the stored duty has exceeded a predetermined value. If the difference has exceeded the predetermined value, supply of the pulse signal stops. When supply of the pulse stops, a conveyance roller is driven.

Abstract: A metering system configured to couple to multiple specialty systems, such as a control system. At least some of the illustrative embodiments are processing units comprising a processor, a memory coupled to the processor, and a communication port configured to coupled to a backbone communication network of a control system. The memory stores a program that causes the processor to selectively participate (over the communication port) as a processing unit of a control system of a first manufacturer (the control system implements a first proprietary communication protocol between processing units), and to participate (over the communication port) as a processing unit of a control system of a second manufacturer different than the first manufacturer (the control system of the second manufacturer implements a second proprietary communication protocol between the processing units).

Abstract: A device, method, computer program and computer readable medium allowing for vehicle to vehicle and vehicle to infrastructure communication. An ignition key radio technology may used in addition to WLAN-based communication in a vehicle in order to communicate with other vehicles or infrastructure. The ignition key radio technology is used to send only selected data which have been altered significantly. The remaining data are not sent or kept for the WLAN communication.

Abstract: The present invention provides a guidance, navigation, and control method and system for an underground mining vehicle that allow said vehicle to be taught a route by a human operator and then have it automatically drive the route with no human intervention. The method works in three steps: teaching, route profiling, and playback. In the teaching step the vehicle is manually driven by a operator along a route which can consist of an arbitrary sequence of maneuvers including tramming forwards, switching directions, tramming backwards, turning, or pausing movement. During this phase raw data from vehicle-mounted sensors including odometric sensors and rangefinders are logged to a file throughout teaching for later processing. During the (offline) route profiling step, the raw data in the log file are processed into a route profile, and a profile of desired speed as a function of distance along the path.

Abstract: A fan control system includes a controller that is coupled to a plurality of fan couplers. A computer-readable medium is coupled to the controller and includes a first fan identification corresponding to a first fan, a second fan identification corresponding to a second fan, and at least one fan property associated with each of the first fan identification and the second fan identification. The controller is operable to monitor at least one operating parameter of each of the first fan and the second fan when the first fan and the second fan are coupled to a respective fan coupler. The controller is further operable to use the at least one fan property associated with each of the first fan identification and the second fan identification and the at least one operating parameter of each of the first fan and the second fan in order to adjust a speed of the second fan relative to a speed of the first fan.

Abstract: Disclosed herein is a velocity and concentration adjustable coupling pipe apparatus equipped between a lifting pipe and a collector. The apparatus includes a coupling pipe having a lower inlet and an upper outlet which are different in diameter from each other. A seawater inlet pipe passes through a side surface of the coupling pipe to permit inflow of seawater. A slurry flow control valve is provided in the coupling pipe to control the inflow of slurry. A seawater flow control valve is provided in the seawater inlet pipe to control the inflow of the seawater. A first sensor measures concentration of slurry discharged through the upper outlet. A second sensor measures velocity of the discharged slurry. A third sensor measures velocity of slurry introduced into the lower inlet. A control panel controls the opening ratio of each of the slurry and seawater flow control valves.

Abstract: An auxiliary power unit has a speed sensor for sensing a speed of operation of the auxiliary power unit. The speed sensor sends a signal to an electronic control box. The electronic control box is operable to control the auxiliary power unit. A branch line is for communicating the speed signal to a health monitoring system. The branch passes through an electronic component that will isolate the speed signal as it passes beyond the component and to the downstream use, such that corruption at a downstream use will not pass back upstream to corrupt the signals used in the electronic control box.

Abstract: The invention relates to a control method for a mechanical-hydraulic system having a degree of freedom per hydraulic actuator which is embodied as a control path, and a measuring sensor which is used to measure the pressure ph of a hydraulic cylinder and a measuring sensor which is used to measure the position xh of the piston of the hydraulic cylinder. A control unit which can receive input variables of hydraulic pressure ph, and hydraulic actuator position xh, is provided. An observer, which determines the desired pressure of the hydraulic system and the speed vh of the hydraulic actuator, is implemented in the system. The desired pressure in the control element is taken into account in the set of rules of the control element and the speed vh of the hydraulic actuator can be over-ridden for attenuating the control element.

Abstract: The invention describes an over-speed governor (21) for a stairlift (10) which not only triggers upon the carriage (12) exceeding a pre-determined speed, but also triggers in the event the chair (11) departs from the horizontal by more than a predetermined angle. The speed determining function is preferably electronic and the governor operates in both directions without adaptation. Other aspects are described including a trip speed check facility.