A diagnostic method for solenoid valves includes detecting, at excitation of the solenoid, a variation rate of the supply voltage of the solenoid and comparing it with a predetermined value, generating an error signal if the variation rate is lower than the predetermined value, otherwise, detecting characteristics of the waveform of the solenoid current over a time interval between a moment of excitation of the solenoid and a moment wherein the movable core reaches end-stroke position, comparing the detected characteristics with threshold values, generating an alarm signal if the detected characteristics are lower than the threshold values, otherwise calculating the value of solenoid resistance and comparing it with a minimum resistance value and a maximum resistance value when the solenoid current is in steady state, and generating an alarm signal if the solenoid resistance value is lower than the minimum resistance value or greater than the maximum resistance value.

A magnetic core and an electric coil, wherein the magnetic core is configured to move by supplying current to the electric coil to allow electrical energy to be transformed into mechanical energy and an electromagnetic actuator operates a valve body to move, and a controller configured to measure a current flowing through the electric coil, select a temporal evaluation section of a course of the current, wherein the current changes from a current value at a beginning of the temporal section to a current value at an end of the section, wherein the evaluation section lasts for a duration period, form an evaluation product from at least the current value at the beginning of the section, the current value at the end of the section, and the duration period of the section, and detect an error function of the actuator by comparing the evaluation product with an evaluation product limit.

A method of adaptively sampling data to determine the start of injection in a solenoid actuated valve of a fluid injector includes, in an operating cycle or portion thereof of the valve, sampling the signal of current through a solenoid of the valve at sampling points having a pre-defined interval therebetween. At each sampling point, determining the value of the first derivative of current and detecting the sampling point at which the first derivative achieves a maximum as the start of injection. Values of the first derivative of the sampling points immediately preceding and immediately following the start of injection are determined. In a subsequent operating cycle, sycrhonisation of sampling is altered to shift sampling times depending on the values of the first derivative of the sampling points immediately preceding and immediately following the start of injection.

A current control device includes a target setting unit, a storage unit, an oil pressure ratio calculation unit, a specific current detection unit and a correction unit. The target setting unit adds a dither amplitude to a target current so that the current of the solenoid periodically changes at a dither cycle period longer than a PWM cycle period of the solenoid. The storage unit stores a stroke-current relationship between a stroke of the spool and the current of the solenoid. The oil pressure ratio calculation unit calculates an oil pressure ratio which is a value calculated by dividing an amplitude of the output oil pressure by an average value of the output oil pressure. The specific current detection unit detects a specific current based on the oil pressure ratio. The correction unit corrects the stroke-current relationship based on the specific stroke and the specific current.

A coil actuator for low and medium voltage applications including a coil electromagnet with a single coil winding and a movable anchor and a power and control unit including: a power circuit operatively coupled with the coil electromagnet, the power circuit including input terminals, at which the power circuit receives an input voltage; a PWM controller operatively coupled with the power circuit, the PWM controller being adapted to control an input current flowing through the power circuit to obtain and maintain an average operating level selected an excitation current feeding the coil electromagnet. The PWM controller is adapted to set a plurality of reference values for the input current to control the input current, each reference value for the input current selected among the plurality of reference values depending on the behavior of the input voltage.

The present disclosure relates to a system for monitoring a solenoid operated valve including at least one coil and at least one spool. The system compares a normalized current signature and a normalized current signature comparator to determine a spool fault condition

A control apparatus for controlling a linear solenoid by controlling a driving current supplied to the linear solenoid through a feedback control. The feedback control is executed by a feedback control system having parameters that are determined in accordance with an ILQ design method. In a frequency characteristic of a gain of a transfer function representing a ratio of an output to a disturbance in the feedback control system, the gain is lower than 0[dB] throughout all frequency ranges.

A method for determining a switching state of a valve, an inductance variable being determined on the basis of current and voltage measurements and the switching state being determined on the basis of the inductance variable. Also disclosed is a solenoid valve assembly for carrying out such a method.

A method for determining a switching state of a valve that is actuated by a coil, wherein the method includes: respectively ascertaining a current flowing through the coil and a voltage applied to the coil at several times which follow one another with a prespecified time interval, calculating an inductance variable of the coil based on the currents, the voltage and the time interval, and determining the switching state based on the inductance variable. Also disclosed is a solenoid valve assembly.

A solenoid assembly includes a solenoid actuator having a core. A coil is configured to be wound at least partially around the core such that a magnetic flux () is generated when an electric current flows through the coil. An armature is configured to be movable based on the magnetic flux (). A controller has a processor and tangible, non-transitory memory on which is recorded instructions for controlling the solenoid assembly. The controller is configured to obtain a plurality of model matrices, a coil current (i.sub.1) and an eddy current (i.sub.2). The magnetic flux () is obtained based at least partially on a third model matrix (C.sub.0), the coil current (i.sub.1) and the eddy current (i.sub.2). Operation of the solenoid actuator is controlled based at least partially on the magnetic flux (). In one example, the solenoid actuator is an injector.