US 7,067,941 B2Granted

Linear solenoid control apparatus and method having increased responsiveness features

AssigneeDenso Corporation

InventorsTakayoshi Honda, Takamichi Kamiya

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Abstract

A control system and method for controlling operation of a group of linear solenoids, which in turn control operation of an electrical load such as a solenoid or actuator, that exhibits increased responsiveness to a change in the target linear solenoid load current. A microcomputer cyclically generates and outputs pulse-width-modulated drive signals based on acquired drive data to establish clock periods. A switch connected between the microcomputer and the target load switchably connects the target load to a power source based on the drive data to selectively drive the target load. A feedback loop between the target load and the microcomputer provides actual target load drive data to the microcomputer, and the microcomputer adjusts the drive signals at a rate of not more than two times per cycle based on the actual drive data to converge the actual drive data to a calculated target load drive value. The present invention also provides an apparatus that prevents a drop in controller current control responsiveness due to signal response delay produced by feedback or the drive system. A converter converts input signals to digital values at a conversion cycle shorter than a cycle of the input signals. A data storage device sequentially stores digital values obtained from the converter, and a processor calculates a mean value to fetch the stored digital values for a cycle time of the input signals, and computes an arithmetic mean of the fetched digital values for target control purposes.

Claims23

Dependent claims

A controller for generating a control signal for driving an electrical load, comprising:

a signal generator for repeatedly generating and outputting pulse-width-modulated signals based on drive data representing signal hold times at respective first and second levels per signal cycle;
a calculator for calculating said drive data at a predetermined calculation cycle and storing said drive data in a data storage device;
a clock for repeatedly clocking a half-cycle time of said pulse-width-modulated signal asynchronously from said calculation cycle of said calculator;
period establishing means for, at first and second determination periods, establishing respective clock periods which are said half-cycle times clocked by said clock in an alternating manner;
drive-data acquiring means for acquiring drive data from said data storage device at each clocking start of said half-cycle time by said clock;
and
signal level determining means for determining, when a clock period of said clock has been established by said period-determining means at said first determining period and based on drive data acquired by said drive-data acquiring means, whether said clock time according to said clock has reached a second time which is half of a time at which said signal per pulse-width-modulated signal cycle is to be held at a second level, and when determined to have reached said second time, to establish a signal level of said pulse-width-modulated signal at a first level, and to determine, when a clock period of said clock has been established by said period-determining means at said second determining period and based on drive data acquired by said drive-data acquiring means, whether said clock time according to said clock has reached a first time which is half of a time at which said signal per pulse-width-modulated signal cycle is to be held at a first level, and when determined to have reached said first time, to establish a signal level of said pulse-width-modulated signal at a second level;
said signal generator for outputting a pulse-width-modulated signal at a signal level established by said signal-level determining means.

5 more elements

A current-control apparatus, comprising:

a calculator for calculating a duty of a pulse-width-modulated signal to enable a predetermined current to flow to an inductive load at each iteration of a predetermined processing cycle;
and
a generator for repeatedly generating a pulse-width-modulated signal in correspondence with a duty calculated by said calculator, and for outputting said pulse-width-modulated signal to a means for energizing said inductive load;
said calculator calculating, from said calculated duty, a level holding time at which said pulse-width-modulated signal is to be held at a first level and a second level each cycle of said pulse-width-modulated signal, and is provided with a data storage device to save said level holding time as drive data;
said pulse-width-modulated signal generating circuit including a clock for repeatedly clocking a time of one-half of one cycle of said pulse-width-modulated signal asynchronously from a processing cycle of said calculator;
means for calculating an inversion time to acquire said drive data from said data storage device synchronously with said clocking operation of said clock, and to respectively calculate one-half of a time at which said signal per cycle of said pulse-width-modulated signal is to be held at a first level as a first time, and similarly a time at which said signal per cycle of said pulse-width-modulated signal is to be held at a second level as a second time;
means for determining clock time to determine, at each clock time whereat said clock clocks said one-half time of said pulse-width-modulated signal cycle time, whether said clock has reached a newest first time calculated by said inversion-time calculating means or whether said clock has reached a newest second time calculated by said inversion-time calculating means;
and
means for establishing a signal level to establish said second level when said clock-time damage means determines that said clock has reached said first time, and to establish said first level when said clock-time damage means determines that said clock has reached said second time;
said pulse-width-modulated signal generating circuit outputting a pulse-width-modulated signal generating circuit outputting a pulse-width-modulated signal at a signal level established by said signal-level establishing means.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/715,279Filed 17 Nov 2003 · division
Priority: JP 10-11095721 Apr 1998
Published: US 2004/0109273 A110 Jun 2004
Granted: 27 Jun 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G05B 11/28
In which the output signal is a pulse-train: using pulse-height modulation; using pulse-width modulation
G05B 19/33
Characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement…:…
G05B 2219/41333
Servomotor, servo controller till figures: non linear solenoid actuator
G05B
Control or regulating systems in general