# US 9,753,443 B2 · Solenoid systems and methods for detecting length of travel

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- Number: US 9,753,443 B2
- Document ID: US9753443B2
- Status: Granted
- Kind: B2
- Application number: 14/690,140
- Filed: 2015-04-17
- Published: 2015-10-22
- Granted: 2017-09-05
- Earliest claimed: 2014-04-21
- Assignees: Synerject, LLC
- Applicants: Synerject LLC
- Inventors: James Fochtman; John Walters
- Web page: https://patentgrep.com/patent/US9753443B2

## CPC

- G05B 15/02: electric
- F04B 17/042: {the solenoid motor being separated from the fluid flow}
- G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G)
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)

## Abstract

In some embodiments, an apparatus includes a solenoid and a solenoid controller. The solenoid is configured to move an actuator a distance between a first position and a second position when a voltage is supplied to the solenoid. The solenoid controller is implemented in at least one of a memory or a processor, and includes a feedback module and an output module. The feedback module is configured to receive a feedback signal associated with a solenoid current after the voltage is removed from the solenoid. The feedback module is further configured to determine whether the distance is less than a maximum distance between the first position and the second position (i.e., a “stroke”). The output module configured to produce an output signal when the feedback module determines that the distance is less than the maximum distance.

## Claims

### Claim 1

An apparatus, comprising:
a solenoid configured to move an actuator a distance between a first position and a second position when a voltage is supplied to the solenoid; and
a solenoid controller implemented in at least one of a memory or a processor, the solenoid controller including a feedback module and an output module, the feedback module configured to receive a feedback signal associated with a solenoid current after the voltage is removed from the solenoid, the feedback module configured to determine whether the distance is less than a maximum distance between the first position and the second position, the output module configured to produce an output signal when the feedback module determines that the distance is less than the maximum distance,
wherein the feedback module determines a time for the solenoid current to decay to a first current value from a time when the voltage is removed from the solenoid, the solenoid controller determining the distance based upon the determined time for the solenoid current to decay to the first current value.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the feedback module is configured to determine, based on the feedback signal, a time period between a second current value and the first current value.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the feedback module is configured to determine, based on the determined time, an inductance of the solenoid.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the solenoid is configured to actuate a fluid transfer pump.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the apparatus is associated with an engine and the output signal is produced to increase a warm up period for the engine when the feedback module determines that the distance is less than the maximum distance, and to decrease or end the warm up period when the feedback module determines that the distance is at the maximum distance.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the solenoid controller includes a driver module configured to supply the voltage to the solenoid, the driver module configured to change an actuation duration in response to at least one of the determined time and the output signal such that when the feedback module determines that the distance is at the maximum distance, the actuation duration is decreased and when the feedback module determines that the distance is less than the maximum distance, the actuation duration is increased.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the feedback module determines the time for the solenoid current to decay to the first current value from thetime when the voltage is removed from the solenoid and when a terminal of the solenoid is clamped so as not to exceed a predetermined voltage, the predetermined voltage being greater than a voltage at which the terminal of the solenoid is clamped during other instances when the voltage is removed from the solenoid, the predetermined voltage allowing for a longer time for the solenoid current to decay to the first current value.

### Claim 8

An apparatus, comprising:
a memory;
a hardware processor operatively coupled to the memory and configured to implement a feedback module at least partially stored in the memory and an output module at least partially stored in the memory,
the feedback module configured to receive a feedback signal associated with a solenoid current after a voltage is removed from a solenoid, the feedback module configured to determine a time for the solenoid current to decay to a first current level from a time when the voltage is removed from the solenoid, and to determine, based upon the determined time for the solenoid current to decay, whether an actuator associated with the solenoid travelled a maximum distance prior to the voltage being removed from the solenoid,
the output module configured to produce an output signal based on the determined time of decay of the solenoid current.

### Claim 9 (depends on 8)

The apparatus of claim 8, wherein:
the solenoid moves the actuator a distance between a first position and a second position when the voltage is supplied to the solenoid; and
the feedback module is configured to determine whether the distance is less than the maximum distance between the first position and the second position based on the decay of the solenoid current.

### Claim 10 (depends on 8)

The apparatus of claim 8, wherein the feedback module is configured to receive the feedback signal at a sample interval of less than 1.5 msec.

### Claim 11 (depends on 8)

The apparatus of claim 8, wherein the apparatus is part of a vehicle having an engine, and the output signal signals a decrease or end to a warm up period for the engine when the actuator is determined to have travelled the maximum distance, and an increase of the warm up period when the actuator is determined to have travelled less than the maximum distance.

### Claim 12 (depends on 8)

The apparatus of claim 8, wherein the hardware processor is configured to implement a driver module configured to supply the voltage to the solenoid, the driver module configured to change an actuation duration in response to the output signal.

### Claim 13 (depends on 8)

The apparatus of claim 8, wherein the hardware processor is configured to implement a driver module configured to supply the voltage to the solenoid, the driver module configured to decrease an actuation duration in response to the actuator being determined to have travelled the maximum distance and to increase the actuation duration in response to the actuator being determined to have travelled less than the maximum distance.

### Claim 14 (depends on 8)

The apparatus of claim 8, wherein the feedback module determines the time for the solenoid current to decay to the first current value from the time when the voltage is removed from the solenoid, the voltage being removed comprising the voltage being removed from a terminal of the solenoid, and when the terminal of the solenoid is clamped so as not to exceed a predetermined voltage, the predetermined voltage being greater than a voltage at which the terminal of the solenoid is clamped during other instances when the voltage is removed from the terminal of the solenoid, the predetermined voltage allowing for a longer time for the solenoid current to decay to the first current value.

### Claim 15

A method, comprising:
receiving a feedback signal associated with a solenoid current after a voltage is removed from a solenoid;
determining a decay time of the solenoid current in response to the feedback signal from a time when the voltage is removed from the solenoid, and determining, based upon the determined decay time, whether or not an actuator associated with the solenoid moves a maximum distance prior to the voltage being removed; and
producing an output signal based on whether the actuator moved the maximum distance.

### Claim 16 (depends on 15)

The method of claim 15, wherein the receiving is performed at a sample interval of less than 1.5 msec.

### Claim 17 (depends on 15)

The method of claim 15, further comprising:
increasing, in response to the determination that the actuator moved less than the, an actuation duration of the voltage supplied to the solenoid and decreasing, in response to the determination that the actuator moved the maximum distance, the activation duration of the voltage supplied to the solenoid.

### Claim 18

A non-transitory processor readable medium storing code representing instructions to be executed by a processor, the code comprising code to cause the processor to:
receive a feedback signal associated with a solenoid current after a voltage is removed from a solenoid;
determine a time for the solenoid current to decay in response to the feedback signal;
based at least upon the determined time for the solenoid current to decay, determine whether an actuator associated with the solenoid moved a maximum distance during a time prior to the voltage being removed from the solenoid;
produce an output signal based on the determined time; and
cause a duration of a next activation period for the solenoid to increase if the actuator is determined to have moved less than the maximum distance.

### Claim 19 (depends on 18)

The non-transitory processor readable medium storing code of claim 18, wherein the solenoid forms part of a vehicle having an engine, and the output signal indicates that a warm up period for the apparatus is to increase if the actuator is determined to have moved less than the maximum distance and indicates that the warm up period is to decrease or end if the actuator is determined to have moved the maximum distance.

### Claim 20 (depends on 18)

The non-transitory processor readable medium storing code of claim 18, wherein the code further causes the processor to voltage clamp the solenoid around the time the voltage is removed from the sollenoid to a predetermined clamping voltage that is larger than a clamping voltage at which the solenoid is clamped in other instances when the voltage is removed from the solenoid.