A driving force transmission control apparatus includes: a driving force transmission device that includes an electromagnetic clutch mechanism configured to generate a frictional force between clutch plates by energization of an electromagnetic coil and transmits a driving force by actuating the electromagnetic clutch mechanism; and a control device that controls the driving force transmission device. The control device includes a storage unit storing a hysteresis value representing the difference between a current value required to transmit a predetermined torque when an energization current to the electromagnetic coil is gradually increased and a current value required to transmit the predetermined torque when the energization current is gradually reduced, a torque command value calculator that calculates a torque command value, and a current command value calculator that calculates a current command value representing a target value of a current to be supplied to the electromagnetic coil based on the torque command value and the hysteresis value.

Methods and systems are provided for operating an electromagnetic coil assembly. As one example, a method comprises responsive to energization of an electromagnetic coil of an electromagnetic coil assembly, translating the electromagnetic coil along a central axis of the electromagnetic coil assembly toward a magnetic armature while maintaining the armature fixed along the central axis. The electromagnetic coil assembly may be utilized within various clutching, braking, or lever applications.

A control device controls a driving force transmission device that presses a main clutch using an actuator that generates a pressing force according to a supply current. The control device includes a current command value setting unit that sets a current command value based on I-T characteristic information indicating the relationship between a current supplied to the actuator and a driving force transmitted, a correction duration setting unit that sets a correction duration based on a responsiveness related value related to the responsiveness of the main clutch when an increase in the driving force to be transmitted by the main clutch becomes greater than or equal to a threshold, a correction unit that increases and corrects the current command value for the set correction duration, and the current control unit that performs current feedback control such that a current corresponding to the current command value is supplied to the actuator.

A torque limiter device includes an input shaft having a first contact surface and an output shaft having a second contact surface. The input and output shafts are operable in an engaged position and a disengaged position A biasing mechanism provides a bias force that mechanically biases the input and output shafts in one of the positions and sets a threshold torque. An electromagnet is arranged to selectively provide an electromagnetic force that opposes the bias force when an activation current is supplied. A controller determines a difference in rotations of the shafts and selectively supply the activation current to the electromagnet so as to disengage the input and output shafts when the rotation difference exceeds a threshold. Each of the contact surfaces comprises one or more grooves, wherein at least one rotatable member is disposed in at least one of said grooves.

A control device according to an embodiment includes a storage, a determining unit, and a driving unit. The storage stores therein information on a hysteresis area of an actuator. The determining unit determines, based on a control mode, a target current value according to the hysteresis area whose information is stored in the storage. The driving unit supplies a driving current according to the target current value determined by the determining unit to the actuator.

A method for controlling power takeoff (PTO) clutch engagement includes determining an output clutch speed, adjusting a clutch current at a predetermined rate, estimating an inertial load of a PTO implement and adjusting the clutch current for one or more times at a time interval, and selecting a clutch control algorithm configured for the inertial load of the PTO implement.

A method for adjusting and adapting an operating point of a hydraulic actuator arrangement, in which a volume flow source is connected to a hydraulic cylinder via a pressure line that is filled with a hydraulic fluid. The method includes regulating a volume of the hydraulic fluid by the volume flow source, wherein an operating point of a position of the actuator arrangement corresponds, with respect to a predefined parameter, to a device which is to be actuated by the actuator arrangement. A modified volume of the hydraulic fluid which is necessary to adjust the operating point is derived from a rotational position of a volume flow source motor and/or of the volume flow source.

In an aspect, a method is provided for controlling a clutch assembly having first and second rotatable clutch members. The method includes providing a wrap spring clutch having first and second ends. The phase angle between the first and second ends determines a diameter of the wrap spring clutch. One of the clutch members is connected with the first end. The method further includes obtaining a target value indicative of a target speed for the second clutch member, and determining through measurement an actual value that is indicative of an actual speed of the second clutch member. The method further includes changing the phase angle between the first and second ends of the wrap spring clutch to generate a selected amount of slip between the wrap spring clutch and the other of the first and second clutch members, based on the target value and the actual value.

In order to pre-stage a clutch piston in preparation for clutch engagement, a controller commands a high current to a Casting Integrated Direct Acting Solenoid (CIDAS) valve. This staging is performed in two distinct phases wherein the current is higher in the first phase than in the second phase. Staging the piston in this manner reduces the staging time and reduces the variability of the staging time. The duration of the first phase may be adjusted based on a number of parameters including, the length of a preceding engine off period, the number of clutch applications since the engine off period, a fluid temperature, and a length of time since a preceding engagement of the clutch.

According to one embodiment, a current detection circuit (12) includes: a detection resistor (Rs) provided between a solenoid valve (106) and a solenoid driver (11); an amplification unit (121) configured to amplify a detected voltage of the detection resistor (Rs); an AD converter (122) that is driven by a reference voltage (Vref) generated based on a reference current (Iref) and configured to convert an output voltage from the amplification unit (121) into a digital value and output the digital value as a detected current value (D1); and a correction unit configured to perform a correction on the detected current value (D1). The correction unit includes: a temperature sensor (123); a storage unit (125) configured to store information about temperature characteristics of the detected current value (D1) generated due to temperature characteristics of a reference current in each of two or more different temperature regions; and an operation unit configured to apply, to the detected current value (D1), a first correction coefficient calculated based on a detection result of the temperature sensor (123) and information about temperature characteristics of the detected current value (D1) stored in the storage unit (125).