# US 2021/0277843 A1 · Method for controlling a dc-dc voltage converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277843 A1 - Document ID: US20210277843A1 - Status: Published application - Kind: A1 - Application number: 17/257,440 - Filed: 2019-07-10 - Published: 2021-09-09 - Earliest claimed: 2018-07-10 - Assignees: Vitesco Technologies GmbH - Applicants: VITESCO TECHNOLOGIES GmbH - Inventors: Jean CANNAVO; Thierry BAVOIS - Web page: https://patentgrep.com/patent/US20210277843A1 ## CPC - F02D 41/20: Output circuits, e.g. for controlling currents in command coils - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - F02D 41/182: {for the control of a fuel injection device} - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 3/157: with digital control - H03K 17/0822: {in field-effect transistor switches} - F02D 41/30: Controlling fuel injection {(F02D41/182, F02D41/24 take precedence)} - F02D 2041/2003: {using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening} - F02D 2041/2006: {by using a boost capacitor} - F02D 2041/2051: {using voltage control} - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract Disclosed is a method for controlling a DC-DC voltage converter for current-driving at least one fuel injector of a motor vehicle internal combustion engine. The method notably includes the steps of determining a time referred to as the “recovery” time at which the output voltage crosses the predefined high voltage threshold, of determining a time referred to as the “drop” time, corresponding to the start of injection, at which the output voltage decreases below the predefined high voltage threshold, and of calculating the time elapsed between the recovery time and the drop time. ## Claims ### Claim 1 A method for controlling a DC-DC voltage converter (1) for current-driving at least one fuel injector (2) of a motor vehicle internal combustion engine, said converter (1) comprising a control module (10) and an induction coil (20) that is connected to a field-effect transistor (30) comprising a drain (D), a source (S) and a gate (G), said gate (G) being connected to the control module (10) in order for said control module (10) to command the transistor (30) to an on state in which current passes between the drain (D) and the source (S) or to an off state in which current does not pass between the drain (D) and the source (S), the alternation of the on and off states of the transistor (30) generating a sawtooth current called the peak current (Ipeak), the amplitude of which varies between 0 and a variable maximum amplitude value that is bounded by a minimum threshold (Ipeak_min) and a maximum threshold (Ipeak_max) and that allows the converter (1) to deliver an output voltage (Vout) across the terminals of a capacitor referred to as the “intermediate” capacitor (Cint), the discharging of which is commanded by a computer via a drive module in order to command at least one fuel injector (2), the converter (1) being configured to make said output voltage (Vout) tend toward a target value, the method comprising: a step (S1) of determining a time referred to as the “recovery” time (T1) at which the output voltage (Vout) crosses a predefined high voltage threshold (VTH_high), a step (S2) of determining a time referred to as the “drop” time (T2), corresponding to the start of injection, at which the output voltage (Vout) decreases below the predefined high voltage threshold (VTH_high), a step (S3) of calculating the time (ΔT) elapsed between the recovery time (T1) and the drop time (T2), if the calculated time (ΔT) is above a predefined time threshold, referred to as the “target” time threshold (ΔT0), and if the value of the maximum amplitude of the peak current (Ipeak) is above the minimum threshold (Ipeak_min), a step (S4) of decreasing the value of the maximum amplitude of the peak current (Ipeak), if the calculated time (ΔT) is below said target time threshold (ΔT0) and if the value of the maximum amplitude of the peak current (Ipeak) is below the maximum threshold (Ipeak_max), a step (S5) of increasing the value of the maximum amplitude of the peak current (Ipeak). ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein the target time threshold (ΔT0) is between 200 and 500 μs. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein the value of the maximum amplitude of the peak current (Ipeak) is decreased by decrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak). ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein the value of the maximum amplitude of the peak current (Ipeak) is increased by incrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak). ### Claim 5 (depends on 1) The method as claimed in claim 1, furthermore comprising a step (S6) of measuring the time elapsed from the drop time (T2) and, when the output voltage (Vout) has not crossed the predefined high voltage threshold (VTH_high) at the end of a predefined time threshold referred to as the “rise” threshold (ΔT2), a step (S7) of increasing the value of the maximum amplitude of the peak current (Ipeak) to the maximum threshold (Ipeak_max). ### Claim 6 A DC-DC voltage converter (1) for current-driving at least one fuel injector (2) of a motor vehicle internal combustion engine, said converter (1) comprising a control module (10) and an induction coil (20) that is connected to a field-effect transistor (30) comprising a drain (D), a source (S) and a gate (G), said gate (G) being connected to the control module (10) in order for said control module (10) to command the transistor (30) to an on state in which current passes between the drain (D) and the source (S) or to an off state in which current does not pass between the drain (D) and the source (S), the alternation of the on and off states of the transistor (30) generating a sawtooth current called the peak current (Ipeak), the amplitude of which varies between 0 and a variable maximum amplitude value that is bounded by a minimum threshold (Ipeak_min) and a maximum threshold (Ipeak_max) and that allows the converter (1) to deliver an output voltage (Vout) across the terminals of a capacitor referred to as the “intermediate” capacitor (Cint), the discharging of which is commanded by a computer via a drive module in order to command at least one fuel injector (2), the converter (1) being configured to make said output voltage (Vout) tend toward a target value, the converter (1) being configured to: determine a time referred to as the “recovery” time (T1) at which the output voltage (Vout) crosses the predefined high voltage threshold (VTH_high), determine a time referred to as the “drop” time (T2), corresponding to the start of injection, at which the output voltage (Vout) decreases below the predefined high voltage threshold (VTH_high), calculate the time (ΔT) elapsed between the recovery time (T1) and the drop time (T2), if the calculated time (ΔT) is above a predefined time threshold, referred to as the “target” time threshold (ΔT0), and if the value of the maximum amplitude of the peak current (Ipeak) is above the minimum threshold (Ipeak_min), decrease the value of the maximum amplitude of the peak current (Ipeak), if the calculated time (ΔT) is below said target time threshold (ΔT0) and if the value of the maximum amplitude of the peak current (Ipeak) is below the maximum threshold (Ipeak_max), increase the value of the maximum amplitude of the peak current (Ipeak). ### Claim 7 (depends on 6) The converter (1) as claimed in claim 6, wherein the target time threshold (ΔT0) is between 200 and 500 μs. ### Claim 8 (depends on 6) The converter (1) as claimed in claim 6, wherein the converter (1) is configured to: decrease the value of the maximum amplitude of the peak current (Ipeak) by decrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak), increase the value of the maximum amplitude of the peak current (Ipeak) by incrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak). ### Claim 9 (depends on 6) The converter (1) as claimed in claim 6, said converter (1) being furthermore configured to measure the time elapsed from the drop time (T2) and, when the output voltage (Vout) has not crossed the predefined high voltage threshold (VTH_high) at the end of a predefined time threshold referred to as the “rise” threshold (ΔT2), increase the value of the maximum amplitude of the peak current (Ipeak) to the maximum threshold (Ipeak_max). ### Claim 10 (depends on 6) A motor vehicle comprising a converter (1) as claimed in claim 6. ### Claim 11 (depends on 2) The method as claimed in claim 2, wherein the value of the maximum amplitude of the peak current (Ipeak) is decreased by decrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak). ### Claim 12 (depends on 2) The method as claimed in claim 2, wherein the value of the maximum amplitude of the peak current (Ipeak) is increased by incrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak). ### Claim 13 (depends on 3) The method as claimed in claim 3, wherein the value of the maximum amplitude of the peak current (Ipeak) is increased by incrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak). ### Claim 14 (depends on 2) The method as claimed in claim 2, furthermore comprising a step (S6) of measuring the time elapsed from the drop time (T2) and, when the output voltage (Vout) has not crossed the predefined high voltage threshold (VTH_high) at the end of a predefined time threshold referred to as the “rise” threshold (ΔT2), a step (S7) of increasing the value of the maximum amplitude of the peak current (Ipeak) to the maximum threshold (Ipeak_max). ### Claim 15 (depends on 3) The method as claimed in claim 3, furthermore comprising a step (S6) of measuring the time elapsed from the drop time (T2) and, when the output voltage (Vout) has not crossed the predefined high voltage threshold (VTH_high) at the end of a predefined time threshold referred to as the “rise” threshold (ΔT2), a step (S7) of increasing the value of the maximum amplitude of the peak current (Ipeak) to the maximum threshold (Ipeak_max). ### Claim 16 (depends on 4) The method as claimed in claim 4, furthermore comprising a step (S6) of measuring the time elapsed from the drop time (T2) and, when the output voltage (Vout) has not crossed the predefined high voltage threshold (VTH_high) at the end of a predefined time threshold referred to as the “rise” threshold (ΔT2), a step (S7) of increasing the value of the maximum amplitude of the peak current (Ipeak) to the maximum threshold (Ipeak_max). ### Claim 17 (depends on 7) The converter (1) as claimed in claim 7, wherein the converter (1) is configured to: decrease the value of the maximum amplitude of the peak current (Ipeak) by decrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak), increase the value of the maximum amplitude of the peak current (Ipeak) by incrementing by a predefined value corresponding to a fraction of the maximum amplitude threshold (Ipeak_max) of the peak current (Ipeak). ### Claim 18 (depends on 7) The converter (1) as claimed in claim 7, said converter (1) being furthermore configured to measure the time elapsed from the drop time (T2) and, when the output voltage (Vout) has not crossed the predefined high voltage threshold (VTH_high) at the end of a predefined time threshold referred to as the “rise” threshold (ΔT2), increase the value of the maximum amplitude of the peak current (Ipeak) to the maximum threshold (Ipeak_max). ### Claim 19 (depends on 8) The converter (1) as claimed in claim 8, said converter (1) being furthermore configured to measure the time elapsed from the drop time (T2) and, when the output voltage (Vout) has not crossed the predefined high voltage threshold (VTH_high) at the end of a predefined time threshold referred to as the “rise” threshold (ΔT2), increase the value of the maximum amplitude of the peak current (Ipeak) to the maximum threshold (Ipeak_max). ### Claim 20 (depends on 7) A motor vehicle comprising a converter (1) as claimed in claim 7.