JP2010288343A - Regenerative braking controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a breaking controller which changes the contents of regenerative control in response to a deceleration changing irregularly, by updating the target deceleration according to the vehicle velocity state and the operation state of a vehicle. <P>SOLUTION: This regenerative braking controller is provided with: a target deceleration computer 43 which computes the target deceleration (T-Dec), based on the detection signals of a vehicle velocity sensor 31, an accelerator sensor 34, and a brake switch 37; and an update determiner 42 which permits or prohibits the update of the target deceleration (T-Dec), based on the detection signals of the vehicle velocity sensor 31, the accelerator sensor 34, and the brake switch 37. Hereby, the controller updates the target deceleration (T-Dec) in response to the present deceleration (St-Dec) changing irregularly, and optimizes the regenerative control of an alternator 23, based on a new target deceleration (T-Dec). Hence, it achieves an improvement in regeneration efficiency and an improvement in fuel consumption. <P>COPYRIGHT: (C)2011,JPO&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.

  An object of the present invention is to provide a regenerative braking control device capable of updating a target deceleration in accordance with a vehicle speed state and an operation state of a vehicle and changing the content of the regenerative control in accordance with an irregularly changing deceleration. There is to do.

  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, Based on the detection signal of the vehicle speed detection means, an actual deceleration calculation means for calculating the actual deceleration of the vehicle, an operation state detection means for detecting the operation state of the vehicle, the vehicle speed detection means, and the operation state detection means Based on detection signals, target deceleration calculation means for calculating the target deceleration of the vehicle, and based on detection signals of the vehicle speed detection means and the operation state detection means, the update of the target deceleration is permitted or not permitted. Target deceleration update means, differential deceleration calculation means for calculating a differential deceleration between the actual deceleration and the target deceleration, and convert the actual deceleration and the differential deceleration, respectively A torque calculating means for calculating the actual regenerative torque and the differential regenerative torque, a target regenerative torque calculating means for calculating a target regenerative torque based on the actual regenerative torque and the differential regenerative torque, and an output current corresponding to the target regenerative torque. And an output current setting means for outputting the output current to the generator.

  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.

  The regenerative braking control device according to the present invention is characterized in that the target regenerative torque calculation means amplifies the target regenerative torque by using the actual regenerative torque as the target regenerative torque when the brake switch is on. .

  In the regenerative braking control device according to the present invention, the target regenerative torque calculating means adds the actual regenerative torque and the differential regenerative torque when the brake switch is off and the vehicle is in a decelerating state. Regenerative torque is used, and the target regenerative torque is amplified each time a predetermined deceleration time elapses.

  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, and target deceleration update means for permitting or not permitting the update of the target deceleration based on the detection signals of the vehicle speed detection means and the operation state detection means, The target deceleration can be updated in correspondence with the irregularly changing deceleration. Therefore, it becomes possible to perform optimal regenerative control by the updated target deceleration, and it is possible to achieve both improvement in regenerative efficiency and improvement in fuel consumption.

  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 calculation means sets the actual regenerative torque as the target regenerative torque and amplifies the target regenerative torque when the brake switch is on. Thus, it is possible to improve the regeneration efficiency and recover more sufficient electric energy.

  According to the regenerative braking control device of the present invention, the target regenerative torque calculating means adds the actual regenerative torque and the differential regenerative torque to obtain the target regenerative torque when the brake switch is off and the vehicle is in a deceleration state. Since the target regenerative torque is amplified every time the deceleration time elapses, the regenerative efficiency during coasting where the vehicle gradually decelerates can be improved.

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. It is a graph (JC08 mode fuel consumption) which shows the 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 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).

  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.

  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, and a brake switch 37.

  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 40, a first conversion unit 41, an update determination unit 42, a target deceleration calculation unit 43, a differential deceleration calculation unit 44, and a target regenerative torque calculation unit 45. , A second conversion unit 46 and an output current setting unit 48.

  A vehicle speed signal (VSO) from the vehicle speed sensor 31 is input to the current deceleration calculation unit (actual deceleration calculation means) 40. The current deceleration calculation unit 40 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 40 is sent to the first conversion unit 41, the update determination unit 42, the target deceleration calculation unit 43, and the differential deceleration calculation unit 44, respectively.

  The first conversion unit (torque calculation means) 41 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 regenerative torque (St_Tq) calculated by the first conversion unit 41 is sent to the target regenerative torque calculation unit 45.

  The update determination unit (target deceleration update means) 42 receives the current deceleration (St_Dec) and the set target deceleration (T_Dec). The update determination unit 42 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 42 subtracts the current deceleration (St_Dec) from the set target deceleration (T_Dec) to calculate a difference value (DecA), and updates the target deceleration (T_Dec) based on a predetermined logic. Whether or not (permitted or not permitted) is determined. The determination result of the update determination unit 42 is sent to the target deceleration calculation unit 43 as a permission signal (OK) or a non-permission signal (NG).

  The permission signal (OK) or non-permission signal (NG) from the update determination unit 42 is input to the target deceleration calculation unit (target deceleration calculation means) 43. The target deceleration calculation unit 43 further receives a current deceleration (St_Dec), a throttle opening amount signal (PW), and a switching signal (ON). The target deceleration calculation unit 43 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 43 sends the newly set target deceleration (T_Dec) or the set target deceleration (T_Dec) to the update determination unit 42 and the differential deceleration calculation unit 44.

  The current deceleration (St_Dec) and the target deceleration (T_Dec) are input to the differential deceleration calculation unit (differential deceleration calculation means) 44. The differential deceleration calculation unit 44 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 44 is sent to the second conversion unit 46.

  The second conversion unit (torque calculation means) 46 performs unit conversion of the differential deceleration (Dif_Dec) based on a predetermined conversion formula, and calculates the differential regenerative torque (Dif_Tq). The differential regenerative torque (Dif_Tq) calculated by the second conversion unit 46 is sent to the target regenerative torque calculation unit 45.

  The target regenerative torque calculation unit (target regenerative torque calculation means) 45 receives the current regenerative torque (St_Tq) and the differential regenerative torque (Dif_Tq), and further receives a switching signal (ON) from the brake switch 37. The target regenerative torque calculation unit 45 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 45 includes a gain multiplication unit 47. The gain multiplication unit 47 performs amplification processing by multiplying the current regenerative torque (St_Tq) and the addition torque (Add_Tq) by a predetermined control gain, respectively. The current regenerative torque (St_Tq) is multiplied by a fixed control gain “1.5”. On the other hand, the additional torque (Add_Tq) is multiplied by a different control gain according to the deceleration time. The gain multiplication unit 47 operates a timer (not shown) that counts the deceleration time of the automobile 10 (see FIG. 1), and sets the control gain “0.7” to the added torque (Add_Tq) for the deceleration time to 2 seconds. Multiply. For the deceleration time of 2 to 4 seconds, the control torque “0.9” is multiplied by the added torque (Add_Tq). After the deceleration time is 4 seconds or more, the control torque “1.2” is multiplied by the additional torque (Add_Tq).

  The target regenerative torque calculation unit 45 sets the optimum load torque (Alt_Tq) that is the target regenerative torque of the alternator 23 in response to the input of the switching signal (ON). When the switching signal (ON) is input, the target regenerative torque calculating unit 45 sends the current regenerative torque (St_Tq) multiplied by the control gain “1.5” to the output current setting unit 48 as the optimum load torque (Alt_Tq). To do. On the other hand, when there is no switching signal (ON) input, the output current is set as the optimum load torque (Alt_Tq) obtained by multiplying the additional torque (Add_Tq) by one of the control gains "0.7", "0.9", or "1.2" To the unit 48.

  Note that the value of the control gain multiplied by the gain multiplier 47 is not limited to the above numerical value. The value of the control gain can be set to any numerical value that provides optimum regeneration efficiency according to the weight of the automobile 10, the capability of the alternator 23, the 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 45 are input to the output current setting unit (output current setting means) 48. The output current setting unit 48 includes an output current map (not shown). The output current setting unit 48 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 48 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 a regenerative braking control device according to the present invention. The graph (JC08 mode fuel consumption) showing the effect of each is shown.

  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 41, The update determination unit 42, the target deceleration calculation unit 43, and the differential deceleration calculation unit 44 are transmitted. The processing contents from step S2 to step S5 indicate the processing contents of the current deceleration calculation unit 40 (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 41 (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 multiplied by the control gain “1.5”. Thereafter, the optimum load torque (Alt_Tq) is set and the process proceeds to step S15. The processing content in step 7 and step S8 has shown the processing content of the target regeneration torque calculation part 45 (refer FIG. 2).

  Here, the control gain when the brake switch 37 is on is “1.5”. This is because the numerical value is close to the maximum value “1.2” of the control gain when the brake switch 37 is OFF. That is, if the difference in the control gain is further increased, the deceleration when braking from the coasting state is rapidly increased, 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. Therefore, as a result of trial calculation of the optimum control gain, “1.5” was obtained as the optimum value that can improve the fuel efficiency without impairing the driving 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 or not 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 43, 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 43, and the process returns to step S9. The processing content in step S9 indicates the processing content of the update determination unit 42 (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 43 (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 44 (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 46 (see FIG. 2).

  In step S13, a determination is made that the brake switch 37 in step S7 is OFF (no), and an additional torque (Add_Tq) is calculated. Thereafter, the process proceeds to step S14.

  In step S14, the added torque (Add_Tq) is multiplied by a control gain “0.7” → “0.9” → “1.2” that increases every time a predetermined time elapses. Thereafter, the optimum load torque (Alt_Tq) is set and the process proceeds to step S15. The processing content in step S7, step S13, and step S14 has shown the processing content of the target regeneration torque calculation part 45 (refer FIG. 2).

  Here, the control gain when the brake switch 37 is OFF is set to “0.7” → “0.9” → “1.2”. This is to gradually increase the deceleration in the inertial running state. That is, if the control gain is fixed at “1.2” from the beginning, for example, the deceleration is the same as the deceleration at the time of 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, if the control gain is fixed at, for example, “0.5”, which is smaller than “1.2”, the deterioration of traveling feeling and the like are improved, but the regeneration efficiency of electric energy is lowered. Therefore, as a result of trial calculation of the optimum value of the control gain and the multiplication timing, “0.7 (deceleration start to 2 seconds)” → “0.9 (2 to 4 seconds)” → “1.2 (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 is.

  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 contents in steps S15 and S16 indicate the processing contents of the output current setting unit 48 (see 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.

  FIG. 5 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 increased, the deceleration may 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. 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 43 that calculates a target deceleration (T_Dec) of the automobile 10, and detection of the vehicle speed sensor 31, the accelerator sensor 34, and the brake switch 37. And an update determination unit 42 that permits or disallows updating of the target deceleration (T_Dec) based on the signal.

  Therefore, the target deceleration (T_Dec) can be updated in correspondence with the current deceleration (St_Dec) that changes irregularly. As a result, the regeneration control of the alternator 23 can be optimized based on the updated new target deceleration (T_Dec), and as a result, both improvement in regeneration efficiency and improvement in fuel consumption can be achieved.

  In addition, according to the regenerative braking control device according to the present embodiment, it is possible to improve the regenerative efficiency and improve the fuel efficiency by changing only the control logic without changing the components of the automobile 10 to dedicated components. it can. Therefore, an increase in manufacturing cost can be suppressed.

  Furthermore, according to the regenerative braking control device according to the present embodiment, the target regenerative torque calculation unit 45 sets the current regenerative torque (St_Tq) to the optimum load torque (Alt_Tq) when the brake switch 37 is on, and gain Since the optimum load torque (Alt_Tq) is amplified by the multiplication unit 47, it is possible to improve the regeneration efficiency during deceleration by the brake operation and to collect more sufficient electric energy.

  In addition, according to the regenerative braking control device according to the present embodiment, the target regenerative torque calculation unit 45 performs the difference regeneration with the current regenerative torque (St_Tq) when the brake switch 37 is off and the automobile 10 is in a deceleration state. The added torque (Add_Tq) obtained by adding the torque (Dif_Tq) is set as the optimum load torque (Alt_Tq), and the optimum load torque (Alt_Tq) is amplified by the gain multiplier 47 every time the deceleration time elapses. It is possible to improve the regeneration efficiency at the time of coasting that gradually decelerates.

  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 Current deceleration calculation unit (actual deceleration calculation means)
41 1st conversion part (torque calculation means)
42 Update determination unit (target deceleration update means)
43 Target deceleration calculation unit (Target deceleration calculation means)
44 Differential deceleration calculation unit (Differential deceleration calculation means)
45 Target regeneration torque calculation unit (target regeneration torque calculation means)
46 2nd conversion part (torque calculation means)
48 Output current setting section (Output current setting means)

Claims (4)

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;
An actual deceleration calculating means for calculating an actual deceleration of the vehicle based on a detection signal of the vehicle speed detecting means;
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;
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 update of the target deceleration;
Differential deceleration calculating means for calculating a differential deceleration between the actual deceleration and the target deceleration;
Torque calculating means for converting the actual deceleration and the differential deceleration, respectively, to calculate the actual regenerative torque and the differential regenerative torque;
Target regenerative torque calculating means for calculating a target regenerative torque based on the actual regenerative torque and the differential regenerative torque;
An regenerative braking control device comprising: output current setting means for setting an output current corresponding to the target regenerative torque and outputting the output current to the generator.   2. 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.   3. The regenerative braking control device according to claim 2, wherein the target regenerative torque calculation means sets the actual regenerative torque as the target regenerative torque and amplifies the target regenerative torque when the brake switch is on. A regenerative braking control device.   4. The regenerative braking control device according to claim 2, wherein the target regenerative torque calculating means adds the actual regenerative torque and the differential regenerative torque when the brake switch is off and the vehicle is in a decelerating state. The regenerative braking control device is characterized in that the target regenerative torque is amplified and amplified every time a predetermined deceleration time elapses.

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