# US 2018/0026532 A1 · Load driving control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0026532 A1 - Document ID: US20180026532A1 - Status: Published application - Kind: A1 - Application number: 15/498,690 - Filed: 2017-04-27 - Published: 2018-01-25 - Earliest claimed: 2016-07-19 - Assignees: Denso Corporation - Applicants: Denso Corporation - Inventors: Yuta MIZUNO - Web page: https://patentgrep.com/patent/US20180026532A1 ## CPC - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - H02M 3/1555: {for the generation of a regulated current to a load whose impedance is substantially inductive} - 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) ## Abstract A load driving control apparatus calculates current slopes in an on-period and an off-period in one PWM cycle period, respectively, by using actual currents at a start time point and an end time point of the PWM cycle period as well as two sets of data, as data including a duty ratio corresponding to the actual current values. The data is so determined that the actual current data value of predetermined one of the start time point and the end time point is within a learning area. The duty ratio is calculated based on a difference between a target current value and the actual current value until calculation of the current slopes and is completed. The duty ratio is calculated based on the current slopes, the actual current value at start time point and a target current value after the calculation of the current slopes is completed. Since an actual current change characteristic is calculated based on the actual current values and the duty ratio is calculated based on the current change characteristic, robustness is enhanced. ## Claims ### Claim 1 A load driving control apparatus for controlling driving of an inductive load, the load driving control apparatus comprising: a switching element provided in a current supply path to the inductive load to supply current to the inductive load when turned on; an actual current value detection part for detecting an actual current value, which is supplied to the inductive load; a duty ratio setting part for setting a duty ratio based on the actual current value and a target current value, which is a target value of the current supplied to the inductive load; and a PWM driving part for generating a PWM signal having the duty ratio, which is set by the duty ratio setting part, at a predetermined cycle period and outputting the PWM signal to the switching element, wherein the duty ratio setting part includes a slope calculating part, a first calculating part and a second calculating part, the slope calculating part calculates a first slope and a second slope indicating slopes of currents in an on-period and an off-period in one cycle period of the PWM signal, respectively, by using the actual current values at a start time point and an end time point of the PWM signal as well as two sets of data, which includes the duty ratios corresponding to the actual current values and the actual current value of predetermined one of the start time point and the end time point of which is within a predetermined current area, the first calculating part calculates the duty ratio based on a difference between the target current value and the actual current value, and the second calculation part calculates the duty ratio based on the first slope, the second slope, the actual current value at the start time point and the target current value, when a predetermined one of the current values between the actual current value at the start time point and the target current value is within the current area, and wherein the PWM driving part generates the PWM signal by using the duty ratio calculated by the first calculating part until calculation of the first slope and the second slope is completed and generates the PWM signal by using the duty ratio calculated by the second calculating part after the calculation of the first slope and the second slope is completed. ### Claim 2 (depends on 1) The load driving control apparatus according to claim 1, wherein: the slope calculating part calculates the first slope and the second slope by using, as the two sets of data, present data including a present value of the actual current value acquired at present time and the duty ratio corresponding to the present value and previous data including a previous value of the actual current value acquired at previous time and the duty ratio corresponding to the previous value. ### Claim 3 (depends on 1) The load driving control apparatus according to claim 1, wherein: the slope calculating part calculates the first slope and the second slope by using, as the two sets of data, an increase-time data at a current increase control time, in which the actual current value is larger at the end time point than at the start time point, and a decrease-time data at a current decrease control time, in which the actual current value is smaller at the end time point than at the start time point. ### Claim 4 (depends on 1) The load driving control apparatus according to claim 1, wherein: a current use range of the inductive load is divided into plural current areas; the current calculating part calculates the first slope and the second slope for each of the current areas; and the second calculating part calculates the duty ratio by using the first slope and the second slope in correspondence to each of the current areas. ### Claim 5 (depends on 1) The load driving control apparatus according to claim 1, wherein: the first calculating part calculates the duty ratio by PID calculation.