JP2011160625A - Device for control of regenerative braking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regenerative braking controller, capable of coping with an irregular deceleration change regardless of the warming-up state of a vehicle, and capable of improving the efficiency of regenerative control. <P>SOLUTION: The regenerative braking controller includes a vehicle speed sensor 31 detecting a vehicle speed, an accelerator sensor 34 detecting an operation state and a brake switch 37, and a target deceleration calculator 53 for calculating a target deceleration (T<SB>-</SB>Dec) on the basis of the detecting signals of the vehicle speed sensor 31, the accelerator sensor 34, and the brake switch 37. The regenerative braking controller further includes an update determiner 52 permitting or inhibiting the update of the target deceleration (T<SB>-</SB>Dec) on the basis of the detecting signals of the vehicle speed sensor 31, the accelerator sensor 34, and the brake switch 37. The regenerative braking controller includes a water-temperature sensor 40 for detecting the warming-up state, and a gain multiplier 58 for generating a variable control gain in response to the result of the detection of the water-temperature sensor 40 and for multiplying the variable control gain by an addition torque (Add<SB>-</SB>Tq). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a regenerative braking control device that collects kinetic energy of a vehicle as electric energy by a generator and charges an in-vehicle power storage unit.

  As a method for improving the fuel consumption (fuel consumption rate) of a vehicle such as an automobile, for example, the kinetic energy of the vehicle is efficiently recovered as electric energy during deceleration, and an electrical device such as an air conditioner is driven by the recovered electric energy. In addition, it is possible to suppress power generation operation (alternator operation) during acceleration or constant speed travel.

  Regeneration efficiency can be improved by controlling the alternator (generator) with emphasis on regeneration. On the other hand, the load torque of the alternator increases, and the deceleration of the vehicle may become larger than expected by the driver. In this case, the driving feeling deteriorates and the driver feels uncomfortable, and in order to avoid this, the driver performs an accelerator operation (acceleration operation), which makes it difficult to improve fuel consumption.

  On the other hand, by controlling the alternator so as to reduce the load torque, it is possible to suppress the deterioration of the running feeling. On the other hand, sufficient electrical energy required for driving the electrical equipment cannot be recovered. As a result, a power generation operation is required during acceleration or constant speed travel, making it difficult to improve fuel consumption.

  Thus, in order to further improve the fuel efficiency of the vehicle, it is desirable to solve the above-mentioned conflicting problems as much as possible. That is, it is necessary to construct a regenerative control that can achieve both the recovery of sufficient electrical energy required for driving the electrical equipment and the suppression of the power generation operation during acceleration or constant speed traveling.

  As a technology related to regenerative control, for example, a regenerative braking control device described in Patent Document 1 is known. The regenerative braking control device of Patent Document 1 is a technology related to regenerative control performed when an electric vehicle such as a forklift is decelerated, a rotation sensor that detects the speed of the vehicle, and a calculation unit that calculates deceleration based on the output of the rotation sensor. And a current control unit that performs regenerative control by the output of the calculation unit.

  In order to set the deceleration calculated by the calculation unit to the target deceleration, a map obtained by experiment / calculation in advance is provided, and the current command output value is obtained by referring to the map. Then, the target current command output value obtained by adding the current command output value to the current current command output value is sent to the output conversion circuit as a current command output. As described above, in the regenerative braking control device of Patent Document 1, the target current command output value for determining the regenerative efficiency is obtained with reference to the map.

Japanese Patent Laid-Open No. 09-093710 (FIGS. 1 to 3)

  According to the regenerative braking control device of Patent Document 1, since regenerative control is performed using a map, in a vehicle traveling on a limited track (such as a factory premises) such as a forklift, the reduction shown in the map is performed. Efficient regeneration control can be performed depending on the speed. However, when the technology is applied to a vehicle that travels on an irregular track such as an automobile, it cannot cope with the deceleration that changes irregularly, and efficient regenerative control becomes difficult. That is, regenerative control using a map is not suitable for regenerative control of a vehicle such as an automobile, and it is necessary to newly construct regenerative control for improving fuel efficiency.

  Further, in an engine as a drive source mounted on a vehicle, a transmission as a power transmission mechanism, and the like, mechanical loss may be different before and after warm-up. Specifically, the frictional resistance of the movable part (gear meshing part, bearing part, etc.), the oil viscosity resistance, and the like may be different before and after warming up. If the mechanical loss before and after the warm-up is not taken into account, for example, the engine brake is too effective before the warm-up, and as a result, the deceleration becomes large and the driving feeling is deteriorated. Acceleration operation (acceleration operation) may make it difficult to improve fuel efficiency. Therefore, in order to perform regenerative control more effectively, it is necessary to consider the difference in mechanical loss before and after warm-up.

  An object of the present invention is to provide a regenerative braking control device that can cope with a deceleration that changes irregularly regardless of the warm-up state of a vehicle and can achieve high efficiency of regenerative control.

  A regenerative braking control device according to the present invention is a regenerative braking control device that collects kinetic energy of a vehicle as electric energy by a generator and charges an in-vehicle power storage unit, the vehicle speed detecting means for detecting the vehicle speed of the vehicle, An operation state detection means for detecting an operation state of the vehicle, a target deceleration calculation means for calculating a target deceleration of the vehicle based on detection signals of the vehicle speed detection means and the operation state detection means, the vehicle speed detection means, Based on the detection signal of the operation state detection means, target deceleration update means for permitting or not permitting the update of the target deceleration by the target deceleration calculation means, and calculating the target regenerative torque based on the target deceleration A target regenerative torque calculating means, a warm-up state detecting means for detecting a warm-up state of the vehicle, and a control gain is generated according to a detection result of the warm-up state detecting means A control gain setting means for multiplying the target regenerative torque by the control gain; and an output current setting for setting the output current corresponding to the target regenerative torque multiplied by the control gain and outputting the output current to the generator Means.

  The regenerative braking control device according to the present invention is characterized in that the warm-up state detecting means is a water temperature sensor for detecting a water temperature of an engine mounted on the vehicle.

  In the regenerative braking control device of the present invention, the operation state detecting means is an accelerator sensor and a brake switch, and detects an acceleration state and a deceleration state of the vehicle.

  In the regenerative braking control device according to the present invention, the target regenerative torque calculation means uses the actual regenerative torque obtained based on the actual deceleration of the vehicle when the brake switch is on as the target regenerative torque, and the control The gain setting means multiplies the target regenerative torque by a fixed control gain.

  In the regenerative braking control device of the present invention, the target regenerative torque calculating means includes an actual regenerative torque obtained based on an actual deceleration of the vehicle when the brake switch is off and the vehicle is in a decelerating state; The differential regeneration torque obtained based on the actual deceleration and the target deceleration is added to obtain the target regeneration torque, and the control gain setting means increases the deceleration time every time a predetermined time elapses in the target regeneration torque. The variable control gain is multiplied.

  According to the regenerative braking control device of the present invention, the vehicle speed detection means for detecting the vehicle speed of the vehicle, the operation state detection means for detecting the operation state of the vehicle, and the detection signals of the vehicle speed detection means and the operation state detection means Target deceleration calculation means for calculating the target deceleration of the vehicle, and target deceleration update that permits or disallows the update of the target deceleration by the target deceleration calculation means based on detection signals of the vehicle speed detection means and the operation state detection means And a control gain for generating a control gain according to a detection result of the warm-up state detection means and multiplying the target regenerative torque by the control gain. Setting means. Therefore, the target deceleration can be updated in correspondence with the irregularly changing deceleration. Therefore, the optimum regenerative control can be performed by the updated target deceleration, and as a result, the efficiency of the regenerative control can be improved and the fuel consumption can be improved. In addition, the generator can be controlled by obtaining a target regeneration torque commensurate with the warm-up state of the vehicle, and thus optimal regeneration control can be performed regardless of the warm-up state of the vehicle.

  According to the regenerative braking control device of the present invention, since the warm-up state detection means is a water temperature sensor that detects the water temperature of the engine mounted on the vehicle, it uses components (existing components) provided in advance in the vehicle. Optimal regenerative control can be performed, and the cost increase of the regenerative braking control device can be suppressed.

  According to the regenerative braking control device of the present invention, the operation state detecting means can be an accelerator sensor and a brake switch, and the acceleration state and the deceleration state of the vehicle can be detected by the accelerator sensor and the brake switch.

  According to the regenerative braking control device of the present invention, the target regenerative torque calculating means sets the actual regenerative torque obtained based on the actual deceleration of the vehicle when the brake switch is on as the target regenerative torque, and the control gain setting means. Since the target regeneration torque is multiplied by a fixed control gain, it is possible to improve the regeneration efficiency during deceleration by the brake operation and recover more sufficient electric energy.

  According to the regenerative braking control device of the present invention, the target regenerative torque calculating means includes the actual regenerative torque obtained based on the actual deceleration of the vehicle when the brake switch is off and the vehicle is in a deceleration state, The differential regenerative torque obtained based on the speed and the target deceleration is added to obtain the target regenerative torque, and the control gain setting means multiplies the target regenerative torque by a variable control gain that increases every time the deceleration time elapses. Therefore, it is possible to improve the regeneration efficiency during coasting where the vehicle gradually decelerates.

It is a schematic diagram which shows the motor vehicle carrying the regenerative braking control apparatus which concerns on this invention. It is a block diagram explaining the internal structure of the controller of FIG. It is a flowchart (main flow) which shows the control content of the controller of FIG. It is a flowchart (subflow) which shows the processing content of the update determination part of FIG. FIG. 3 is a flowchart (subflow) showing a calculation process content of a variable control gain in a gain multiplication unit of FIG. 2. It is a graph (JC08 mode fuel consumption) which shows the effect of the regenerative braking control device concerning the present invention. It is a graph which shows the temperature correction effect of the regenerative braking control device concerning the present invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an automobile equipped with a regenerative braking control device according to the present invention, and FIG. 2 is a block diagram for explaining the internal structure of the controller of FIG.

  As shown in FIG. 1, an automobile 10 as a vehicle includes a vehicle body 11, a pair of front wheels 12a and 12b, and a pair of rear wheels 13a and 13b. The front wheels 12a and 12b and the rear wheels 13a and 13b are provided on the vehicle body 11 via suspension devices (not shown).

  An engine 14 as a drive source is disposed between the front wheels 12a and 12b. A transmission 15 is provided integrally with the engine 14. The transmission 15 is speed-changed by a shift lever (not shown) in the passenger compartment. A pair of drive shafts 16 a and 16 b are provided between the front wheels 12 a and 12 b and the transmission 15. One end of each drive shaft 16a, 16b is connected to each front wheel 12a, 12b via a universal joint (not shown). The other end of each drive shaft 16a, 16b is connected to the transmission 15 via a universal joint. The automobile 10 according to the present embodiment is a front-wheel drive type vehicle in which the front wheels 12 a and 12 b are driven by the engine 14.

  Hydraulic brake devices 17 are provided in the vicinity of the front wheels 12a and 12b and the rear wheels 13a and 13b, respectively. Each brake device 17 includes a disk rotor 17a and a caliper 17b. Each caliper 17 b is connected to a master cylinder 20 provided in the vehicle body 11 via a front hydraulic pipe 18 and a rear hydraulic pipe 19. Each brake device 17 is operated by hydraulic pressure from the master cylinder 20.

  A first pulley 22 is provided on the crankshaft 21 of the engine 14 so as to be integrally rotatable. An alternator 23 serving as a generator is disposed close to the crankshaft 21 side (lower side in the figure) of the engine 14. A second pulley 25 is provided on the rotating shaft 24 of the alternator 23 so as to be integrally rotatable. Between the 1st pulley 22 and the 2nd pulley 25, the V belt 26 which has a core wire inside is spanned. The tension of the V belt 26 is held constant by a tension pulley (not shown), and the V belt 26 efficiently transmits the rotational force of the first pulley 22 to the second pulley 25. The rotating shaft 24 of the alternator 23 always rotates with the operation of the engine 14. Here, instead of the power transmission method using the V-belt 26, a power transmission method using a chain may be used.

  The alternator 23 is integrally provided with an IC regulator (not shown). The IC regulator is electrically connected to a lead storage battery 28 as an in-vehicle power storage unit via a wiring 27. The alternator 23 generates power by the operation of the engine 14 and charges the lead storage battery 28. The regeneration efficiency of the alternator 23 is controlled by the in-vehicle controller 29. The in-vehicle controller 29 controls the alternator 23 to efficiently recover the kinetic energy of the automobile 10 as electric energy.

  The in-vehicle controller 29 is installed around the glove box (not shown) in the vehicle interior. The in-vehicle controller 29 includes an interface (not shown) for connecting various connection devices. The IC regulator of the alternator 23 is electrically connected to the interface of the in-vehicle controller 29 via the wiring 30.

  In the vicinity of the drive shaft 16a, a vehicle speed sensor (vehicle speed detection means) 31 that detects the rotational state of the drive shaft 16a, that is, the vehicle speed (vehicle speed) of the automobile 10, is provided. The vehicle speed sensor 31 is electrically connected to the interface of the in-vehicle controller 29 via the wiring 32. As the vehicle speed sensor 31, for example, a Hall IC type is used. The vehicle speed sensor 31 generates a pulse signal having a pulse number proportional to the rotational speed of the drive shaft 16a. The pulse signal from the vehicle speed sensor 31 is sent to the in-vehicle controller 29 as a vehicle speed signal (detection signal).

  An accelerator sensor (operation state detecting means) 34 is electrically connected to the interface of the in-vehicle controller 29 via a wiring 33. As the accelerator sensor 34, for example, a Hall IC type sensor is used. The accelerator sensor 34 detects the amount of depression of an accelerator pedal 35 disposed close to a floor (not shown) on the driver's seat side, that is, the acceleration state (operation state) of the vehicle. The accelerator sensor 34 sends the depression amount of the accelerator pedal 35 to the in-vehicle controller 29 as a throttle opening amount signal (detection signal).

  A brake switch (operation state detecting means) 37 is electrically connected to the interface of the in-vehicle controller 29 via a wiring 36. The brake switch 37 detects a depressing operation of the brake pedal 38 disposed in proximity to the floor or the like on the driver's seat side, that is, a deceleration state (operation state) of the vehicle. The brake switch 37 generates a switching signal when the brake pedal 38 is depressed. The switching signal of the brake switch 37 is sent to the in-vehicle controller 29 as an ON signal (detection signal). The brake operation state is detected by a switch ON signal, but the present invention is not limited to this as long as it is a means for detecting the brake operation state.

  A piston (not shown) is slidably provided in the master cylinder 20 shown in FIG. The piston slides in the master cylinder 20 in proportion to the depression amount of the brake pedal 38. As a result, a hydraulic pressure having a magnitude proportional to the depression amount of the brake pedal 38 is supplied to each caliper 17b via each pipe 18 and 19. When the amount of depression of the brake pedal 38 is large, in addition to regenerative braking by power generation by the alternator 23, braking by each brake device 17 is added.

  A water temperature sensor (warm-up state detection means) 40 is electrically connected to the interface of the in-vehicle controller 29 via a wiring 39. The water temperature sensor 40 is attached to a water jacket (not shown) formed in the cylinder block of the engine 14 and detects the warm-up state of the automobile 10. The water temperature sensor 40 is an electric water thermometer, detects the cooling water temperature (water temperature) of the engine 14 based on a change in resistance value, and sends the detected water temperature signal to the in-vehicle controller 29. The water temperature signal from the water temperature sensor 40 is used to reflect the frictional resistance of the movable part and the viscous resistance of the oil that are different before and after the engine 14 is warmed up in the regenerative braking of the alternator 23.

  However, as long as the warm-up state of the automobile 10 can be detected, not only the water temperature sensor 40 attached to the cylinder block but also the cooling water such as the transmission 15, the radiator and the cooling water hose (not shown) can circulate. A water temperature sensor attached to the location can also be used. Further, since a signal proportional to the warm-up state may be obtained, an exhaust temperature sensor (not shown) attached to the catalyst or the like of the automobile 10 can also be used. Thus, the warm-up state detection means in the present invention is formed by existing parts such as a water temperature sensor and an exhaust temperature sensor provided in advance in the automobile 10.

  Here, the regenerative braking control device according to the present invention includes an alternator 23, a lead storage battery 28, an in-vehicle controller 29, a vehicle speed sensor 31, an accelerator sensor 34, a brake switch 37, and a water temperature sensor 40.

  Next, the internal structure of the in-vehicle controller 29 will be described in detail with reference to the drawings.

  As shown in FIG. 2, the in-vehicle controller 29 includes a current deceleration calculation unit 50, a first conversion unit 51, an update determination unit 52, a target deceleration calculation unit 53, a differential deceleration calculation unit 54, and a target regenerative torque calculation unit 55. , A second conversion unit 56 and an output current setting unit 57.

  A vehicle speed signal (VSO) from the vehicle speed sensor 31 is input to the current deceleration calculation unit (actual deceleration calculation means) 50. The current deceleration calculation unit 50 monitors the change in the vehicle speed signal (VSO) and calculates the current deceleration (St_Dec) as the actual deceleration. The current deceleration (St_Dec) calculated by the current deceleration calculation unit 50 is sent to the first conversion unit 51, the update determination unit 52, the target deceleration calculation unit 53, and the differential deceleration calculation unit 54, respectively.

  The first conversion unit (torque calculation means) 51 performs unit conversion of the current deceleration (St_Dec) based on a predetermined conversion formula, and calculates the current regenerative torque (St_Tq) as the actual regenerative torque. The current regeneration torque (St_Tq) obtained based on the current deceleration (St_Dec) in the first conversion unit 51 is sent to the target regeneration torque calculation unit 55.

  The update determination unit (target deceleration update means) 52 receives the current deceleration (St_Dec) and the set target deceleration (T_Dec). The update determination unit 52 further receives a throttle opening amount signal (PW) from the accelerator sensor 34 and a switching signal (ON) from the brake switch 37. The update determination unit 52 subtracts the current deceleration (St_Dec) from the set target deceleration (T_Dec) to calculate a difference value (DecA), and based on a predetermined logic, the target deceleration calculation unit 53 performs the target deceleration. It is determined whether or not the update of the speed (T_Dec) is permitted (permitted or not permitted). The determination result of the update determination unit 52 is sent to the target deceleration calculation unit 53 as a permission signal (OK) or a non-permission signal (NG).

  The permission signal (OK) or the disapproval signal (NG) from the update determination unit 52 is input to the target deceleration calculation unit (target deceleration calculation means) 53. The target deceleration calculation unit 53 further receives a current deceleration (St_Dec), a throttle opening amount signal (PW), and a switching signal (ON). The target deceleration calculation unit 53 newly calculates and sets a target deceleration (T_Dec) when the permission signal (OK) is input. On the other hand, when the non-permission signal (NG) is input, the set target deceleration (T_Dec) is held as it is. The target deceleration calculation unit 53 sends the newly set target deceleration (T_Dec) or the set target deceleration (T_Dec) to the update determination unit 52, the differential deceleration calculation unit 54, and the target regenerative torque calculation unit 55. To do.

  The current deceleration (St_Dec) and the target deceleration (T_Dec) are input to the differential deceleration calculation unit (differential deceleration calculation means) 54. The differential deceleration calculation unit 54 calculates the differential deceleration (Dif_Dec) by subtracting the current deceleration (St_Dec) from the target deceleration (T_Dec). The differential deceleration (Dif_Dec) calculated by the differential deceleration calculation unit 54 is sent to the second conversion unit 56.

  The second conversion unit (torque calculation means) 56 performs unit conversion of the differential deceleration (Dif_Dec) based on a predetermined conversion formula, and differential regeneration obtained based on the current deceleration (St_Dec) and the target deceleration (T_Dec). Torque (Dif_Tq) is calculated. The differential regenerative torque (Dif_Tq) calculated by the second conversion unit 56 is sent to the target regenerative torque calculation unit 55.

  The current regenerative torque (St_Tq) and the differential regenerative torque (Dif_Tq) are input to the target regenerative torque calculating unit (target regenerative torque calculating means) 55, and further, the target deceleration (T_Dec), the switching signal (ON), and the water temperature sensor A water temperature signal (Eg_temp) from 40 is input. The target regenerative torque calculation unit 55 holds the current regenerative torque (St_Tq) as it is and calculates an addition torque (Add_Tq) obtained by adding the current regenerative torque (St_Tq) and the differential regenerative torque (Dif_Tq).

  The target regenerative torque calculation unit 55 includes a gain multiplication unit (control gain setting means) 58. The gain multiplication unit 58 performs amplification processing by multiplying the current regeneration torque (St_Tq) and the addition torque (Add_Tq) as the target regeneration torque by predetermined control gains (fixed control gain FG and variable control gain VG), respectively.

  The current regenerative torque (St_Tq) is multiplied by a preset fixed control gain FG. Here, the fixed control gain FG is set to “1.5”, for example.

  The added torque (Add_Tq) is multiplied by a variable control gain VG that increases according to the deceleration time. The gain multiplication unit 58 operates a timer (not shown) that counts the deceleration time of the automobile 10 (see FIG. 1). For the deceleration time of 0.2 to 2 seconds, the additional torque (Add_Tq) is multiplied by the first control gain 0.7. For the deceleration time of 2 to 4 seconds, the additional torque (Add_Tq) is multiplied by the second control gain 0.9. After the deceleration time is 4 seconds, the third control gain 1.2 is multiplied by the additional torque (Add_Tq). For 0.2 seconds from the start of deceleration, the variable control gain VG is set to “0” and regenerative braking by the alternator 23 is not executed (non-regenerative period). As described above, the variable control gain VG increases in four steps of “0”, “0.7”, “0.9”, and “1.2” according to the deceleration time.

  The gain multiplication unit 58 executes a process for optimizing the variable control gain VG, that is, a temperature correction process for the variable control gain VG, according to the water temperature signal (Eg_temp) from the water temperature sensor 40. In the temperature correction processing of the variable control gain VG, for example, before warming up, based on the input water temperature signal (Eg_temp) and the friction coefficient (f) of the engine 14, transmission 15, etc., the HOT deceleration torque after warming up ( Hot_Tq) is estimated. Further, based on the input target deceleration (T_Dec), the actual deceleration torque before warm-up, that is, the COLD deceleration torque (Cold_Tq) is calculated. Then, a temperature correction coefficient R is calculated from the ratio between the estimated HOT deceleration torque (Hot_Tq) and the actual COLD deceleration torque (Cold_Tq), and a process of multiplying the temperature correction coefficient R by the variable control gain VG is performed. That is, the gain multiplication unit 58 generates a variable control gain VG obtained by multiplying the temperature correction coefficient R according to the water temperature signal (Eg_temp), and executes a process of multiplying the variable control gain VG by the addition torque (Add_Tq). Here, the variable control gain VG multiplied by the temperature correction coefficient R forms the control gain in the present invention.

  The target regenerative torque calculation unit 55 sets the optimum load torque (Alt_Tq) of the alternator 23 according to the input of the switching signal (ON). When the switching signal (ON) is input, the target regenerative torque calculation unit 55 multiplies the current regenerative torque (St_Tq) by the fixed control gain FG (here, “1.5”) from the start of deceleration to the optimum load torque (Alt_Tq ) To the output current setting unit 57. On the other hand, when the switching signal (ON) is not input, the variable torque gain VG (here, “0.7 × R” → “0.9 × R” → “1.2 ×” is added to the additional torque (Add_Tq) after the deceleration time has elapsed for 0.2 seconds. The product obtained by multiplying the order of “R”) is sent to the output current setting unit 57 as the optimum load torque (Alt_Tq).

  Note that the values of the fixed control gain FG and the variable control gain VG multiplied by the gain multiplier 58 are not limited to the above numerical values. The values of the control gains FG and VG can be set to any numerical value that provides optimum regeneration efficiency according to the weight of the automobile 10, the ability of the alternator 23, the transmission gear ratio of the transmission 15, and the like.

  The optimum load torque (Alt_Tq) and the rotation speed (Alt_rpm) of the alternator 23 from the target regenerative torque calculation unit 55 are input to the output current setting unit (output current setting means) 57. The output current setting unit 57 includes an output current map (not shown). The output current setting unit 57 refers to the output current map and sets the output current (Alt_A) corresponding to the input optimum load torque (Alt_Tq) and rotation speed (Alt_rpm). The output current setting unit 57 outputs the set output current (Alt_A) to the alternator 23, and the alternator 23 is regeneratively controlled (Output) based on the output current (Alt_A).

  Next, the operation of the in-vehicle controller 29 will be described in detail with reference to the drawings.

  3 is a flowchart (main flow) showing the control contents of the controller of FIG. 2, FIG. 4 is a flowchart (sub-flow) showing the processing contents of the update determination unit of FIG. 2, and FIG. 5 is the temperature in the gain multiplication unit of FIG. FIG. 6 is a flowchart (JC08 mode fuel efficiency) showing the effect of the regenerative braking control device according to the present invention, and FIG. 7 is the temperature of the regenerative braking control device according to the present invention. Each graph shows a correction effect.

  As shown in FIG. 3, regenerative braking control is started by turning on an ignition switch (not shown) or the like (step S1).

  In step S2, a vehicle speed signal (VSO) from the vehicle speed sensor 31 is read based on the start of regenerative braking control.

  In step S3, the acceleration / deceleration of the automobile 10 is calculated based on the read vehicle speed signal (VSO). The acceleration / deceleration is obtained by subtracting the vehicle speed signal (VSO) in the previous control cycle temporarily stored and held from the vehicle speed signal (VSO) in the current control cycle.

  In step S4, it is determined whether or not the automobile 10 is in a decelerating state with reference to whether the acceleration / deceleration obtained in step S3 is “positive” or “negative”. If the acceleration / deceleration is “positive”, that is, it is determined (no) that the vehicle 10 is not in a deceleration state, the process returns to step S2, and the acceleration / deceleration is “negative”, that is, the steps in steps S2 and S3 until the vehicle 10 is in a deceleration state. Repeat the process. If it is determined in step S4 that the automobile 10 is in a decelerating state (yes), the process proceeds to step S5.

  In step S5, the sign of the deceleration obtained in step S3 is inverted from “negative” to “positive” to generate the current deceleration (St_Dec), and the generated current deceleration (St_Dec) is converted into the first conversion unit 51, The data are sent to the update determination unit 52, the target deceleration calculation unit 53, and the differential deceleration calculation unit 54, respectively. The processing contents from step S2 to step S5 indicate the processing contents of the current deceleration calculation unit 50 (see FIG. 2).

  In step S6, the current regenerative torque (St_Tq) is calculated by performing unit conversion of the current deceleration (St_Dec). Then, it progresses to step S7. The processing content in step S6 indicates the processing content of the first conversion unit 51 (see FIG. 2).

  In step S7, it is determined whether or not a switching signal (ON) is input from the brake switch 37, that is, whether or not the brake switch 37 is on. If it is determined (yes) that the brake switch 37 is on, the process proceeds to step S8.

  In step S8, the current regenerative torque (St_Tq) is set as the target regenerative torque, and a fixed control gain FG (eg, “1.5”) is multiplied. Thereafter, the optimum load torque (Alt_Tq) is set and the process proceeds to step S15.

  Here, the fixed control gain FG when the brake switch 37 is on is set to “1.5”, which is a value close to the maximum value “1.2 × R” of the variable control gain VG when the brake switch 37 is off. It is to do. That is, if the difference between the fixed control gain FG and the variable control gain VG is increased more than this, the deceleration when braking from the inertial running state increases rapidly, resulting in a deterioration in running feeling. In addition, in order to avoid the deterioration of the driving feeling, the driver performs the accelerator operation (acceleration operation), and the fuel consumption is deteriorated. Therefore, as a result of trial calculation of the optimum fixed control gain FG, “1.5” was obtained as the optimum value that can improve the fuel consumption without impairing the running feeling.

  In parallel with the processes in steps S6 to S8, the processes in steps S9 to S14 are executed.

  In step S9, it is determined whether to update the target deceleration (T_Dec) based on the current deceleration (St_Dec) from step S5 and the target deceleration (T_Dec) from step S10. If it is determined to update (OK) in step S9, a permission signal (OK) is sent to the target deceleration calculation unit 53, and the process proceeds to step S10. On the other hand, if it is determined not to update (NG), a non-permission signal (NG) is sent to the target deceleration calculation unit 53, and the process returns to step S9. The processing content in step S9 indicates the processing content of the update determination unit 52 (see FIG. 2).

  In step S10, a new target deceleration (T_Dec) is calculated and set when the permission signal (OK) is input. On the other hand, when the non-permission signal (NG) is input, the set target deceleration (T_Dec) is held. Then, it progresses to step S11. The processing content in step S10 indicates the processing content of the target deceleration calculation unit 53 (see FIG. 2).

  In step S11, the current deceleration (St_Dec) is subtracted from the target deceleration (T_Dec) to calculate a differential deceleration (Dif_Dec). Thereafter, the process proceeds to step S12. The processing content in step S11 indicates the processing content of the differential deceleration calculation unit 54 (see FIG. 2).

  In step S12, the differential deceleration (Dif_Dec) is converted into a unit, and the differential regenerative torque (Dif_Tq) is calculated. Thereafter, the process proceeds to step S13. The processing content in step S12 indicates the processing content of the second conversion unit 56 (see FIG. 2).

  In step S13, in response to the determination (no) that the brake switch 37 is OFF in step S7, the additional torque (Add_Tq) as the target regenerative torque is calculated. Thereafter, the process proceeds to step S14.

  In step S14, the addition torque (Add_Tq) is sequentially multiplied by a variable control gain VG that increases every time a predetermined time elapses, that is, “0” → “0.7” → “0.9” → “1.2”. The gain multiplier 58 (see FIG. 2) calculates a temperature correction coefficient R in the non-regenerative period from the start of deceleration to 0.2 seconds, and multiplies the calculated temperature correction coefficient R by the variable control gain VG (temperature correction process). )I do. Then, the variable control gain VG subjected to the temperature correction process is multiplied by the addition torque (Add_Tq), and the addition torque (Add_Tq) is set as the optimum load torque (Alt_Tq), and the process proceeds to step S15.

  Here, the processing content in step S7, step S8, step S13, and step S14 has shown the processing content of the target regeneration torque calculation part 55 and the gain multiplication part 58 (refer FIG. 2).

  The variable control gain VG when the brake switch 37 is OFF is changed so as to increase in steps of “0” → “0.7 × R” → “0.9 × R” → “1.2 × R”. This is because the deceleration in the coasting state is gradually increased. That is, if the variable control gain VG is set to “1.2 × R” from the beginning, for example, the deceleration is the same as the deceleration during braking, and the driving feeling is deteriorated. In addition, in order to avoid the deterioration of the driving feeling, the driver performs the accelerator operation (acceleration operation), and the fuel consumption is deteriorated. On the other hand, when the variable control gain VG is set to, for example, “0.5 × R” which is smaller than “1.2 × R”, the deterioration of traveling feeling is improved, but the regeneration efficiency of electric energy is lowered. Therefore, as a result of trial calculation of the optimum value of the variable control gain VG and the multiplication timing, “0 (deceleration start to 0.2 seconds) →“ 0.7 × R (0.2 to 2 seconds) ”→“ 0.9 × R (2 to 4 seconds) ” → "1.2 x R (after 4 seconds)" was obtained.

  In step S15, an output current (Alt_A) is set using an output current map based on the optimum load torque (Alt_Tq) and the rotation speed (Alt_rpm) of the alternator 23. The optimum load torque (Alt_Tq) used in step S15 is the optimum load torque (Alt_Tq) from step S8 when the brake switch 37 is on, and the optimum load torque (Alt_Tq) from step S14 when the brake switch 37 is off. It becomes.

  In the subsequent step S <b> 16, the set output current (Alt_A) is output to the alternator 23. Then, it returns to step S2 and repeats the process of step S2-step S16. The processing content in step S15 and step S16 has shown the processing content of the output current setting part 57 (refer FIG. 2).

  Next, the processing content in step S9, that is, the processing content of the target deceleration update determination will be described in detail with reference to FIG.

  In step S110, the throttle opening amount signal (PW) from the accelerator sensor 34 is read. In step S111, it is determined whether or not the throttle opening amount is “0.1%” or more. If it is determined as yes in step S111, the process proceeds to parallel processing of step S115 and step S117. Thereby, the determination in step S9 becomes OK, and the target deceleration (T_Dec) can be updated.

  Here, although the automobile 10 is in a decelerating state, a throttle opening amount signal (PW) is detected in step S110. This is to cope with a situation where the driver wants to reduce the deceleration by operating the accelerator when the target deceleration (T_Dec) of the automobile 10 is larger than expected by the driver. Therefore, the comparative reference value of the throttle opening is set to “0.1%” so that it can be detected that the accelerator is operated even a little. Thus, the target deceleration (T_Dec) can be updated when the automobile 10 is in a decelerating state and the accelerator is operated.

  In step S112, a difference value (DecA) is calculated by subtracting the current deceleration (St_Dec) from the set target deceleration (T_Dec). Then, it progresses to the parallel processing of step S113 and step S114.

  In step S113, it is determined whether or not the difference value (DecA) is smaller than “0”. If it is determined as yes in step S113, the process proceeds to parallel processing of step S115 and step S117. Thereby, the determination in step S9 becomes OK, and the target deceleration (T_Dec) can be updated. The case where the difference value (DecA) is smaller than “0” means that the current deceleration (St_Dec)> the target deceleration (T_Dec). If the target deceleration (T_Dec) is not updated in this state, the actual deceleration of the automobile 10, that is, the current deceleration (St_Dec) will be weakened. As a result, the regeneration efficiency is reduced. Therefore, the target deceleration (T_Dec) is updated in accordance with the larger current deceleration (St_Dec).

  In step S114, it is determined whether or not the difference value (DecA) is equal to or greater than “0.1”. If it is determined as yes in step S114, the process proceeds to parallel processing of step S115 and step S117. Thereby, the determination in step S9 becomes OK, and the target deceleration (T_Dec) can be updated. The case where the difference value (DecA) is “0.1” or more is a case where the current deceleration (St_Dec) <target deceleration (T_Dec) and there is a difference of “0.1” or more. If the target deceleration (T_Dec) is not updated even though there is a difference of “0.1” or more, the target deceleration (T_Dec) is too strong and the driver operates the accelerator. As a result, fuel consumption is deteriorated. Therefore, when there is a difference of “0.1” or more, the target deceleration (T_Dec) is updated in accordance with the smaller current deceleration (St_Dec).

  Here, if any one of the determinations in steps S111, S113, and S114 is yes, the process proceeds to the parallel processing in steps S115 and S117, and the target deceleration (T_Dec) is updated. It has become. That is, when all the determinations at steps S111, S113, and S114 are no, the determination at step S9 is NG and the target deceleration (T_Dec) is not updated.

  In step S115, it is determined whether or not the current deceleration (St_Dec) is equal to or less than “0”. If it is determined yes in step S115, that is, if the automobile 10 is in a stopped state or an accelerated state, the process proceeds to step S116. If it is determined no in step S115, that is, if the automobile 10 is in a decelerating state, the determination in step S9 is OK and the target deceleration (T_Dec) can be updated.

  Here, the sign of the current deceleration (St_Dec) is reversed in step S5 shown in FIG. 3, where “positive” indicates a deceleration state and “negative” indicates an acceleration state. Therefore, the yes determination in step S115 (when the current deceleration (St_Dec) is “0” or less) is when the automobile 10 is in a stopped state or an accelerated state.

  In step S116, the target deceleration (T_Dec) is set to “0” based on the fact that the vehicle 10 is stopped or accelerated. Here, the target deceleration (T_Dec) is reset by setting the target deceleration (T_Dec) to `` 0 '', so that the target deceleration (T_Dec) that has been set in the previous control cycle will be The regenerative control is not adversely affected.

  In step S117, it is determined whether or not a switching signal (ON) is input from the brake switch 37. If it is determined as yes in step S117, the process proceeds to step S118. If it is determined no in step S117, the determination in step S9 is OK and the target deceleration (T_Dec) can be updated.

  In step S118, the target deceleration (T_Dec) is set to “0” in response to the input of the switching signal (ON). Here, the target deceleration (T_Dec) is reset by setting the target deceleration (T_Dec) to `` 0 '', so that the target deceleration (T_Dec) that has been set in the previous control cycle will be The regenerative control is not adversely affected.

  Next, the processing contents of the gain multiplication unit 58 in step S14, particularly the calculation processing contents of the temperature correction coefficient R to be multiplied by the variable control gain VG will be described in detail with reference to FIG. Here, description will be made assuming that the engine 14 is in a state before warm-up (during cold operation immediately after engine startup).

  In step S210, the gain multiplication unit 58 reads the target deceleration (T_Dec) set by the target deceleration calculation unit 53. Then, it progresses to the parallel processing of step S211 and step S212. In step S211, the input target deceleration (T_Dec) is held as a deceleration before warm-up, that is, COLD deceleration (Cold_Dec), and the process proceeds to step S213.

  In step S214, the water temperature signal (Eg_temp) from the water temperature sensor 40 is read. In step S212, based on the friction coefficient (f) of the engine 14 stored in advance in the gain multiplier 58 and a predetermined function (formula), the deceleration after warm-up is performed from the target deceleration (T_Dec) and the water temperature signal (Eg_temp). That is, the HOT deceleration (Hot_Dec) is calculated. In subsequent step S215, the HOT deceleration (Hot_Dec) calculated in step S212 is held as an estimated value. Here, since the HOT deceleration (Hot_Dec) is calculated using a predetermined function, it can be easily applied to other vehicle types having different engines and transmissions. In other words, the coefficient used in the function can be dealt with by tuning based on the information of other vehicle types, and for example, there is no need to form a HOT deceleration estimation map for each vehicle type.

  In step S213, unit conversion of COLD deceleration (Cold_Dec) from step S211 and HOT deceleration (Hot_Dec) from step S215 is performed to calculate COLD deceleration torque (Cold_Tq) and HOT deceleration torque (Hot_Tq). Then, it progresses to Step S216 and Step S217, respectively.

  In step S216, the COLD deceleration torque (Cold_Dec) converted in units in S213 is held as it is. In step S217, the HOT deceleration torque (Hot_Dec) converted in units in S213 is held as it is.

  In subsequent step S218, the temperature correction coefficient R is calculated from these ratios using the COLD deceleration torque (Cold_Dec) and the HOT deceleration torque (Hot_Dec). The temperature correction coefficient R is calculated by HOT deceleration torque (Hot_Dec) / COLD deceleration torque (Cold_Dec). Since the COLD deceleration torque (Cold_Dec) is before warm-up, the frictional resistance, the oil viscosity resistance, and the like are large, and thus show a value larger than the HOT deceleration torque (Hot_Dec). Therefore, the temperature correction coefficient R is a numerical value of “1” or less.

  In the subsequent step S219, a process of multiplying the variable control gain VG by the temperature correction coefficient R is executed, and the temperature correction process of the variable control gain VG is thereby completed. As a result, it is possible to suppress an increase in deceleration due to a large frictional resistance and oil viscosity resistance before the engine 14 is warmed up (during COLD). That is, by multiplying the variable control gain VG by the temperature correction coefficient R, the deceleration before warming up of the automobile 10 can be brought close to the deceleration after warming up (during HOT).

  However, if the engine 14 is already in a state after warm-up (HOT state) when this control logic is started, the COLD deceleration (Cold_Dec) and COLD deceleration torque (Cold_Tq) in Step S211 and Step S216 However, the values represent the HOT deceleration (Hot_Dec) and the HOT deceleration torque (Hot_Tq), respectively. Accordingly, the temperature correction coefficient R is substantially “1”, which is approximately the same as when the temperature correction process for the variable control gain VG is not executed.

  FIG. 6 shows a graph based on JC08 mode fuel consumption. Looking at the conventional example (map control) indicated by the broken line graph, the enlarged circle portions A and B in the figure are particularly separated from the reference vehicle speed to the lower side in the figure. That is, in the conventional example, although the regeneration efficiency is improved, the deceleration tends to be too large. As a result, the driver performs an accelerator operation, and there is a concern about deterioration of fuel consumption. On the other hand, when the present invention shown by the solid line graph is seen, it can be seen that the vehicle speed changes substantially along the reference vehicle speed. This means that an unnecessary accelerator operation by the driver can be avoided, and therefore an improvement in fuel consumption can be expected.

  FIG. 7 is a comparison graph based on the presence or absence of temperature correction processing, and shows how the inertial state of the automobile 10 changes after starting coasting at a vehicle speed of 35 km / h. When no temperature correction (in the case of COLD) indicated by the broken line graph is seen, the portion of the enlarged circle portion C in the figure is far away from the target deceleration particularly in the figure. This is because the engine 14 is not warmed up, so that the frictional resistance, the viscous resistance of oil, and the like are large, and the regeneration control by the alternator 23 is performed as usual. That is, the deceleration becomes too large, and the driver performs an accelerator operation, which may cause a deterioration in fuel consumption. On the other hand, when the present invention shown by the solid line graph is seen, it can be seen that it changes so as to substantially follow the target deceleration. This means that an unnecessary accelerator operation by the driver can be avoided, and therefore an improvement in fuel consumption can be expected.

  Regarding the regenerative efficiency of the present invention, when the brake switch 37 is turned on or off, the current regenerative torque (St_Tq) or the additional torque (Add_Tq) is multiplied by the optimized control gain, so that the regenerative efficiency decreases. Is kept to a minimum.

  As described above in detail, according to the regenerative braking control device according to the present embodiment, the vehicle speed sensor 31 that detects the vehicle speed of the automobile 10, the accelerator sensor 34 and the brake switch 37 that detect the operation state of the automobile 10, Based on detection signals from the vehicle speed sensor 31, the accelerator sensor 34, and the brake switch 37, a target deceleration calculation unit 53 that calculates a target deceleration (T_Dec) of the vehicle 10, and detection of the vehicle speed sensor 31, the accelerator sensor 34, and the brake switch 37. An update determination unit 52 that permits or disallows updating of the target deceleration (T_Dec) based on the signal. Further, a water temperature sensor 40 that detects the warm-up state of the automobile 10, and a gain multiplier 58 that generates a variable control gain VG according to the detection result of the water temperature sensor 40 and multiplies the addition torque (Add_Tq) by the variable control gain VG. And.

  Therefore, the target deceleration (T_Dec) can be updated in correspondence with the current deceleration (St_Dec) that changes irregularly. Thereby, the regenerative control of the alternator 23 can be optimized based on the updated new target deceleration (T_Dec), and as a result, both the high efficiency of the regenerative control and the improvement of the fuel consumption can be achieved. Further, the alternator 23 can be controlled by obtaining the optimum load torque (Alt_Tq) from the added torque (Add_Tq) corresponding to the warm-up state of the vehicle 10, and thus optimal regenerative control can be performed regardless of the warm-up state of the vehicle 10. it can.

  In addition, according to the regenerative braking control device according to the present embodiment, only the control logic is used while using components (existing components) provided in advance in the vehicle 10 without changing the components of the vehicle 10 to dedicated components. Optimal regenerative control can be performed simply by changing the value. Therefore, the cost increase of the regenerative braking control device can be suppressed.

  Furthermore, according to the regenerative braking control device according to the present embodiment, the target regenerative torque calculation unit 55 sets the current regenerative torque (St_Tq) as the target regenerative torque when the brake switch 37 is on, and the gain multiplication unit 58. Since the target regeneration torque is multiplied by the fixed control gain FG, the regeneration efficiency at the time of deceleration by the brake operation can be improved and more sufficient electric energy can be recovered.

  In addition, according to the regenerative braking control device according to the present embodiment, the target regenerative torque calculation unit 55 performs the differential regenerative torque (St_Tq) and the differential regenerative operation when the brake switch 37 is off and the automobile 10 is in the decelerating state. Since the addition torque (Add_Tq) obtained by adding the torque (Dif_Tq) is set as the target regenerative torque, the gain multiplication unit 58 multiplies the addition torque (Add_Tq) by the variable control gain VG that increases every time the deceleration time elapses. In addition, it is possible to improve the regeneration efficiency at the time of coasting where the automobile 10 is gradually decelerated.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the regenerative braking control device is applied to the automobile 10 having the engine 14 and the alternator 23. However, the present invention is not limited to this, and a hybrid having an engine and a motor generator. It can also be applied to vehicles and the like.

  Moreover, in the said embodiment, although what used the lead storage battery 28 as a vehicle-mounted electrical storage body was shown, this invention is not restricted to this, If it is a secondary battery, electrochemical capacitors, such as an electric double layer capacitor, will be employ | adopted. You can also

  Further, in the above-described embodiment, the regenerative braking control device is applied to the front-wheel drive vehicle 10 that drives the front wheels 12a and 12b. However, the present invention is not limited to this, and the rear wheels are driven. The present invention can also be applied to a rear-wheel drive vehicle and a four-wheel drive vehicle that drives front and rear wheels.

10 Automobile (vehicle)
23 Alternator (generator)
28 Lead-acid battery (on-vehicle storage battery)
31 Vehicle speed sensor (vehicle speed detection means)
34 Accelerator sensor (operation state detection means)
37 Brake switch (operation state detection means)
40 Water temperature sensor (warm-up state detection means)
50 Current deceleration calculation unit (actual deceleration calculation means)
51 1st conversion part (torque calculation means)
52 Update determination unit (target deceleration update means)
53 Target deceleration calculation unit (target deceleration calculation means)
54 Differential deceleration calculation unit (Differential deceleration calculation means)
55 Target regeneration torque calculation unit (target regeneration torque calculation means)
56 2nd conversion part (torque calculation means)
57 Output current setting section (output current setting means)
58 Gain multiplier (control gain setting means)
VG Variable control gain (control gain)

Claims (5)

A regenerative braking control device that collects kinetic energy of a vehicle as electrical energy by a generator and charges an in-vehicle power storage unit,
Vehicle speed detecting means for detecting the vehicle speed of the vehicle;
Operation state detection means for detecting the operation state of the vehicle;
Target deceleration calculation means for calculating a target deceleration of the vehicle based on detection signals of the vehicle speed detection means and the operation state detection means;
Target deceleration update means for permitting or not permitting the update of the target deceleration by the target deceleration calculation means based on detection signals of the vehicle speed detection means and the operation state detection means;
A target regenerative torque calculating means for calculating a target regenerative torque based on the target deceleration;
A warm-up state detecting means for detecting a warm-up state of the vehicle;
Control gain setting means for generating a control gain according to the detection result of the warm-up state detection means, and multiplying the target regeneration torque by the control gain;
A regenerative braking control device comprising: output current setting means for setting an output current corresponding to the target regenerative torque multiplied by the control gain and outputting the output current to the generator.   2. The regenerative braking control device according to claim 1, wherein the warm-up state detecting means is a water temperature sensor that detects a water temperature of an engine mounted on the vehicle.   3. The regenerative braking control device according to claim 1, wherein the operation state detecting means is an accelerator sensor and a brake switch, and detects an acceleration state and a deceleration state of the vehicle.   The regenerative braking control device according to claim 3, wherein the target regenerative torque calculating means sets the actual regenerative torque obtained based on the actual deceleration of the vehicle when the brake switch is on as the target regenerative torque, The regenerative braking control device, wherein the control gain setting means multiplies the target regenerative torque by a fixed control gain.   5. The regenerative braking control device according to claim 3, wherein the target regenerative torque calculation means is obtained based on an actual deceleration of the vehicle when the brake switch is off and the vehicle is in a deceleration state. The regenerative torque and the differential regenerative torque obtained based on the actual deceleration and the target deceleration are added to obtain the target regenerative torque, and the control gain setting means has a deceleration time elapses for the target regenerative torque. A regenerative braking control device that multiplies a variable control gain that increases each time the control is performed.

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