KR101541711B1 - Vehicle and braking control method thereof - Google Patents

Abstract

The present invention relates to a vehicle which uses power generated by a motor to perform regenerative braking and a braking control method thereof. The braking control method of a vehicle, which uses power generated by a motor to perform regenerative braking, comprises: a step of receiving a braking command; a step of responding to the braking command to measure the condition of a battery disposed in the vehicle; and a step of selectively using the regenerative braking or using a braking resistor disposed in the vehicle to perform braking based on the measured condition of the battery.

Description

VEHICLE AND BRAKING CONTROL METHOD THEREOF FIELD OF THE INVENTION [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a vehicle and a braking control method thereof, and more particularly, to a vehicle and a braking control method thereof for performing regenerative braking using power generated by a motor.

According to the Korean Industrial Standard (KS), "Automobile is equipped with a prime mover and a steering device, and it is a vehicle that can ride on the ground to ride on it." Depending on where you get the car power, the car can be divided into diesel car, electric car, LPG car, gasoline car and hybrid car, but the basic principle of moving cars is the same.

The car was built in 1891 by Panhard Levassor of France, and many rear-wheel-drive cars now employ this structure. The car is made up of 30,000 parts, but the main part is divided into the body (frame) and the rest of the chassis (chassis). The chassis can be divided into engines, power transmission units, and wheels.

Furthermore, the vehicle is provided with a braking device for performing the braking function. A braking device is a device that reduces or stops the speed of a vehicle by changing the kinetic energy of the vehicle to another type of energy. As an example of the braking device, there is a brake.

On the other hand, interest in high fuel efficiency and environmentally friendly hybrid vehicles and electric vehicles is increasing day by day. These vehicles are equipped with braking and parking brakes as well as conventional motors, and they are equipped with a function to recover kinetic energy using a motor (regenerative braking or eddy current retarder). .

Electro-hydraulic brakes are becoming popular as the main motive brake applied to vehicles. This is designed to electrically determine the driver's intention of the driver, and to form the braking back pressure in consideration of the operation of the ABS, TCS, etc. which helps the intention of the driver and the safety of the vehicle. Particularly, in the case of a hybrid vehicle, regenerative braking is considered, so that the braking force required by the driver is recognized, and the braking force of the regenerative braking and the main braking brake is properly distributed in the vehicle. This electrohydraulic brake can be applied to ABS, TCS, VDC as compared with the general brake system, so it is necessary for the safety but the complex hydraulic line is still needed.

On the other hand, the braking resistor is an apparatus mounted on electric base operating vehicles (railroad, crane, etc.) of high weight, and is a device for converting kinetic energy of a vehicle into heat energy. This is because the kinetic energy is too high for braking with mechanical brakes only when the vehicle is stopped, so as to suppress the vapor lock and fade phenomenon, increase the service life of the parts, maintain the braking force and minimize the braking distance.

In a typical case, a vehicle using a motor-generated power (for example, a hybrid vehicle, an electric vehicle, or the like) is not equipped with a braking resistor, which is why the unit price and weight increase when the braking resistor is attached . Even when mounted, the braking resistor is merely used to protect the circuit from excessive back electromotive force. Specifically, a power diode or the like is attached to a circuit to protect an electric device mounted on the vehicle. When the back electromotive force is excessive, a circuit to the braking resistor is opened and the back electromotive force is operated in a manner of burning in the braking resistor.

However, the increasing anxiety about the vehicle abnormality due to mutual interference, contact failure, and algorithm error due to electromagnetic noise in a vehicle where more and more devices are being electronicized is increasing, and the part related to braking is also not free from this. The vehicle is important to run, but more importantly it must be able to stop and under any circumstances the braking should be a guarantee for the driver, passenger, and pedestrian safety. However, in most hybrid vehicles and electric vehicles, the application of electrohydraulic brakes for regenerative braking does not always result in proportional brake pedal depression and braking force of the main brake, If the brake pedal is pressed, the brake may not be activated. Even if the hydraulic brake is equipped with a backup circuit, only an insufficient braking force can be exerted. Particularly, when the vehicle is in a state in which the battery can not be recharged (low temperature or full load state) or when there is a problem in inverter control, the regenerative braking is not possible and the vehicle is in a braking disabled state.

In a situation where the motive brake is not activated, a general vehicle may gradually stop the engine by gradually lowering the engine speed to engage the engine brake, and if the vehicle speed is sufficiently low, the parking brake may be operated to stop the vehicle. However, this method is applied to the hybrid vehicle There is no braking means other than a parking brake with low braking power.

In a similar case, on a downhill road that lasts for an extended period of time, in the case of a regular vehicle, the engine brakes can be safely lowered at low speeds, but the electric vehicle has no engine. Therefore, when the regenerative braking is not possible due to low temperature, high temperature, full battery, battery abnormality, etc., the main brake only becomes the braking means. As the downward length becomes longer, The possibility of losing braking power is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and it is an object of the present invention to provide a vehicle capable of exhibiting a high braking force in order to secure the safety of a driver in a fuel cell vehicle, a hydrogen vehicle, a hybrid vehicle, And to provide a control method.

It is another object of the present invention to provide a vehicle and a braking control method thereof that perform braking using a braking resistor in a state in which regenerative braking is not possible while avoiding the use of the main brake.

It is also an object of the present invention to provide a braking force that prevents breakage of an electrical component caused by a back electromotive force generated in a motor and responds to a driver's intention.

It is another object of the present invention to provide a vehicle capable of forcibly braking a vehicle in a situation in which a sudden acceleration is suspected, and a braking control method thereof.

In order to achieve the above object, the present invention provides a braking control method for a vehicle, which uses regenerative braking using power generated by a motor, the method comprising: receiving a braking command; Measuring the state of the battery, and performing braking using the regenerative braking selectively based on the measured state of the battery or using a braking resistor provided in the vehicle.

In one embodiment, the step of selectively performing the braking based on the measured state of the battery may include performing the braking using the regenerative braking if the measured state of the battery satisfies a predetermined criterion And performing the braking using the braking resistor when the measured state of the battery does not satisfy the pre-set criterion.

In one embodiment, the predetermined condition is related to at least one of a charge amount of the battery, a temperature of the battery, and a chargeability of the battery.

In one embodiment, the braking control method of the vehicle further includes performing the braking using the braking resistor as well as the brakes provided in the vehicle when a load larger than a reference is applied to the braking resistor .

In one embodiment, the braking command includes a braking amount to be braked, and performing the braking using the braking resistor may include: switching the power generated by the motor to the braking resistor, / OFF of the control signal based on the braking amount.

In one embodiment, at least one of an ON / OFF period and a speed of the switch unit is varied according to the amount of the braking.

In one embodiment, when the braking according to the braking command is terminated, the power generated by the motor is prevented from being transmitted to the braking resistor, and the battery is charged by the electric power generated by the motor. And a step of adjusting the part.

In one embodiment, the braking command includes a braking amount to be braked, and the step of performing the braking using the braking resistor further includes adjusting an impedance value of the braking resistor based on the braking amount .

In one embodiment, the amount of power flowing in at least one of the battery and the braking resistor varies in real time according to the braking amount.

In one embodiment, the vehicle further includes a forced brake switch configured to perform forced braking until the vehicle is stopped, the method comprising: receiving a user input to the forced brake switch; And performing braking using the braking resistor in response to the user input.

In one embodiment, the braking control method of the vehicle further includes a step of controlling the electric connection between the motor and the electrical component, when the back electromotive force supplied from the motor during braking using the braking resistor exceeds the internal pressure range of the electrical component Further comprising the step of:

The effects of the vehicle and its braking control method according to the present invention will be described as follows.

According to at least one of the embodiments of the present invention, the braking is performed by measuring the state of the battery in response to the braking command and selectively using the regenerative braking or the braking resistor according to the measured state of the battery, It is possible to effectively perform braking in a situation where the braking force by regenerative braking is insufficient.

Even in the case where the vehicle can not be normally operated due to a control problem in a highly electronicized modern vehicle or when braking is difficult, stable deceleration can be performed using the braking resistance provided in the vehicle, thereby increasing vehicle safety.

According to at least one of the embodiments of the present invention, since the motive brake is used only when a load greater than the reference is applied to the brake resistor, wear of the motive brake is minimized. In addition, it is possible to prevent the braking force from being lost due to a phenomenon such as a vapouring phenomenon or a fading phenomenon.

According to at least one of the embodiments of the present invention, the amount of braking can be adjusted by turning on / off the circuit from the motor to the braking resistor, or adjusting the input impedance of the braking resistor. Accordingly, braking in response to the driver's intention can be performed by the braking resistor. That is, as many brakes as the driver desires can be made by the brake.

According to at least one of the embodiments of the present invention, since the braking resistor is provided in the vehicle, the internal pressure range of the electrical component can be improved. When there is no braking resistor, the counter electromotive force must be controlled within a range that does not exceed the internal voltage range of the electrical component. However, when the braking resistor is mounted, excessive counter electromotive force can be transmitted to the braking resistor. Therefore, when designing a vehicle, it is possible to use parts that are easier and less expensive when setting the internal pressure range of each component.

1 is a block diagram for explaining a configuration of a vehicle related to the present invention;
2 is a flowchart for explaining a braking control method of a vehicle according to the present invention.
3 is a block diagram for explaining a configuration of a control unit of a vehicle according to the present invention;
4 is a conceptual diagram for explaining more specifically the contents related to the motor inverter of the vehicle according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a braking resistor applied to a vehicle, and more particularly, to a braking resistor and a braking resistor using the braking resistor in a hybrid vehicle, an electric vehicle, a fuel cell vehicle, To a braking control method. In the vehicle according to the present invention, by using the braking resistor, when the braking of the braking amount required by the driver can not be achieved by the regenerative braking, the deceleration of the vehicle can be induced by converting the kinetic energy into heat energy. Since the braking resistor is easy to install, the degree of freedom of installation is improved, and the reliability of braking is improved in that braking is performed without using the main brake in a state in which regenerative braking is not possible.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram for explaining a configuration of a vehicle related to the present invention.

Referring to FIG. 1, a vehicle according to the present invention includes a circuit line 180, a motor 120, a motor inverter 122, and a generator 160. (Not shown), a braking resistor control unit 110, a braking resistor 140, a forcible braking switch 170, an electrical component 130, and a battery 150. The generator inverter 162,

The components shown in Fig. 1 are not essential for implementing a vehicle, so that the vehicle described herein may have more or less components than those listed above. For example, the functions of the generator and the generator inverter can be performed by a motor and a motor inverter, respectively.

 The components are electrically connected by a circuit line 180. A circuit line 180 provided in the vehicle and supplying power to the battery 150, the generator 160, the generator inverter 162, the motor inverter 122, the motor 120, and the electrical equipment 130, The braking resistor 140 is connected in a circuit.

Meanwhile, the motor according to the present invention may be connected to the motor inverter 122, the generator inverter 162, and the generator 160 to perform regenerative braking.

Here, regenerative braking is a braking method in which a motor (or an electric motor) is operated as a generator and the generated electric power is returned to a power source to charge the battery or the like. More specifically, a method for obtaining the braking force by consuming electric power generated by the motor during braking in an electronic equipment for powering or transferring it to a substation is called a regenerative braking. In addition to the spread of inverter control system, regenerative braking is adopted.

The motive brakes are devices that convert kinetic energy (motion) into other types of energy. Traditional braking systems use friction of the brake pads to reduce kinetic energy to heat. Although this system is effective, it has low energy efficiency, and due to problems such as abrasion of accessories due to friction, a method of using some kinetic energy as a fuel has been sought.

Internal combustion engines and vehicles powered by fossil fuels were unable to utilize inertia as fuel, but electric vehicles powered by motors could solve this problem through regenerative braking. A coil of an electric vehicle generates a magnetic field repulsive to a magnet located in the rotor, and the electric power transmission through the coil generates a motive force of the electric vehicle. If the motor's motion is reversed during the brake operation, the magnet will generate electricity in the coil and the generated electricity will be stored. For example, a battery 150 provided in a vehicle, or the like.

Hybrid and electric vehicles generally perform the regenerative braking described above in order to increase the fuel efficiency during braking. However, in the vehicle according to the present invention, when braking force beyond regenerative braking is required in a situation where regenerative braking is not possible, braking by braking resistance can be performed. The braking resistor 140 can be used instead of or in combination with the regenerative braking and the main braking depending on the state of the battery as well as in an emergency through the active intervention of the braking resistor control unit 110.

The braking resistor 140 is formed of a device including a resistor or a resistor. The braking resistor control unit 110 converts the kinetic energy into electric energy through the power generation function of the motor 120 and converts the converted electric energy into the thermal energy by transmitting the electric energy to the braking resistor 140. That is, the braking resistor 140 converts electric energy into thermal energy when power is transmitted by the braking resistor control unit 110.

The braking resistor control unit 110 transmits or cuts off the current to the braking resistor 140 and may adjust the amount of the current supplied to the braking resistor 140 based on the braking command.

The braking resistor control unit 110 according to the present invention may exist in software or hardware, and may be installed to be able to operate independently of controllers provided in other vehicles. Therefore, when it is determined that normal control of the vehicle is impossible due to an error of the controller and components, the braking resistor control unit 110 ignores the command from the control unit such as the HCU, 140 can be operated.

Errors in the controller and / or errors in the internal components can be determined through the degree to which the value communicated via the CAN communication differs from the existing trend. The braking resistor control unit 110 ignores the command of the upper control unit and uses the braking resistor 140 to perform the braking operation when the predetermined condition is satisfied (or an error of the controller and / or an internal component is detected) Can be performed.

Further, the vehicle may be provided with a forced braking switch 170 that is configured to perform forced braking until the vehicle is stopped. The driver may apply the user input to the gait braking switch 170 located in the vicinity of the steering wheel. In this case, the braking resistor control unit 110 performs braking using the braking resistor 140 irrespective of commands from other controllers or the upper control unit. Since the braking resistor 140 must be unconditionally operated when the driver operates the forcible braking switch 170, the braking resistor control unit 110 is not configured only algorithmically, but physically changes the current path It can also be done in hardware. Thereby, reliability against forced braking can be assured.

In order to operate the regenerative braking or braking resistor, the motor inverter 122 must boost the counter electromotive force voltage to be higher than the battery 150. The battery 150 is charged only when the counter electromotive force voltage is higher than the voltage of the battery 151, so that the regenerative braking is enabled and the braking by the braking resistor can be performed. At this time, the braking resistor control unit 110 may control the amount of braking resistor braking by alternately opening and closing the circuit to the braking resistor, and adjusting the impedance value of the braking resistor to adjust the amount of power flowing to the battery and the braking resistor You can use the method you take.

More specifically, the braking resistor control unit 110 controls the ON / OFF of the switch unit for transmitting or interrupting the electric power generated by the motor 120 to the braking resistor 140 to a braking amount (or a braking demand amount) included in the braking command . At this time, the braking resistor control unit 110 may variably change at least one of the on / off cycle and the speed of the switch unit according to the braking amount, thereby performing braking corresponding to the driver's intention. The braking resistor control unit 110 stops the electric power generated by the motor 120 from being transmitted to the braking resistor 140 and outputs the electric power generated by the motor 120 to the braking resistor 140. [ So that the battery 150 is charged by the electric power generated in the battery 150. [ Thus, the amount of electric power flowing in at least one of the battery 150 and the braking resistor 140 varies in real time according to the braking amount.

Also, the braking resistor control unit 110 can perform the braking corresponding to the braking amount by adjusting the impedance value of the braking resistor 140 based on the braking amount included in the braking command. Thus, the amount of electric power flowing in at least one of the battery 150 and the braking resistor 140 varies in real time according to the braking amount.

On the other hand, the braking resistance using the braking resistor is immediately controlled because of its electrically controlled characteristics. Therefore, in the vehicle in which the motor and the motor inverter are independently provided for each axle or wheel, the existing body posture control system (ESP or VDC) can be simulated through the braking resistor 140. Unlike a conventional ESP device that catches and brakes a brake shoe, the vehicle according to the present invention can instantaneously control the counter electromotive force of a plurality of motors by using a braking resistor, thereby adjusting the torque of each wheel. Therefore, while the same effect as ESP can be obtained, the hydraulic line is unnecessary, which increases the degree of freedom in vehicle design and simplifies the components. In addition, durability and reliability are advantageous because electrical braking is performed instead of controlling by mechanical friction.

On the other hand, in a vehicle such as an electric hybrid vehicle in which an engine brake can not be used and a hybrid hybrid vehicle in which an engine is separated from an axle because the engine is not available, the battery is fully charged when descending downhill, Since the regenerative braking is not possible, the motive brake must be operated to decelerate the vehicle. In this case, there is a high possibility that fade and vapor lock phenomena, which are safety problems, occur. In the vehicle according to the present invention, the braking resistance braking force is arbitrarily adjusted by a driver through a paddle shift, The same effect can be given. That is, a braking input unit capable of performing braking using a braking resistor in stages can be provided on a steering wheel of the vehicle. The vehicle can perform braking as much as the user requires based on the user input applied to the braking input unit by using the braking resistor. For example, a braking system consisting of one-stage braking (maximum speed 20 km / h), two-speed braking (maximum speed 40 km / h), three-speed braking (maximum speed 60 km / h) When the user input is applied to the three-step braking with the input unit provided, the speed is reduced to 60 km / h by the braking resistor. Therefore, drivers can safely descend the hill without feeling a sense of discomfort in the operation of the vehicle. In addition, even in the case of steep downhill, it is possible to simulate the DBC function of the ramp in addition to the regenerative braking, so that it can be lowered at low speed without braking.

In summary, it is possible to simulate the effects of ESP, DBC, engine brakes, etc. electrically by installing a brake resistor, which can inhibit vehicle design constraints and vehicle price increase factors due to complicated hydraulic lines and components. In the case of vehicles without an engine or physically separated from an axle, it is possible to increase the safety through engine brake simulation.

On the other hand, braking by the braking resistor is performed by a user input applied to the braking input unit, and an additional braking force can be adjusted based on a user input applied to a brake pedal provided in the vehicle. For example, if a user input is applied to the braking input section corresponding to the third-stage braking during traveling at 100 km / h, braking is performed up to 60 km / h by the braking resistance. On the other hand, if a user input is applied to the brake pedal during deceleration from 100 km / h to 60 km / h, additional braking is performed using at least one of regenerative braking, braking resistance and main brake. That is, if an additional braking amount is required by the user input applied to the brake pedal, the vehicle can decelerate to 60 km / h more quickly or to decelerate at a speed lower than 60 km / h.

Meanwhile, the vehicle according to the present invention performs braking using at least one of the regenerative braking and the main brake applied to the vehicle when a user input is applied to a brake pedal provided in the vehicle. If the at least one braking does not satisfy the predetermined deceleration criterion, the vehicle performs the braking using the braking resistor regardless of the state of the battery. That is, when it is determined that the deceleration is not performed despite the fact that the driver has stepped on the brake, it is determined that the driver has the deceleration intention and the braking using the braking resistor is performed. At this time, the predetermined deceleration reference may be variously modified according to the embodiment.

On the other hand, in order to determine that deceleration of the vehicle is not performed despite the fact that the brake pedal is depressed, the braking resistor control unit 110 may utilize the existing vehicle speed detection sensor.

For example, the vehicle may be provided with a separate sensor or signal transfer circuit for obtaining the brake pedal displacement signal and the vehicle speed or deceleration information, and the braking resistor control unit 110 may include a signal transmitted from a separate sensor or signal transmission circuit It is possible to determine whether braking is to be performed using the braking resistor. At this time, the displacement of the brake pedal and the vehicle deceleration displacement may be compared to determine whether the predetermined deceleration criterion is satisfied.

For example, the braking resistor control unit 110 may output the vehicle deceleration information to a vehicle speed sensor such as a wheel speed sensor, a navigation GPS information value, or an acceleration sensor such as a smart phone or a tablet PC, To determine the deceleration of the vehicle, and to decide whether to braking using the braking resistor.

The electrical component 130 refers to an electric / electronic sub-assembly (ESA) that operates upon receiving power. Components including a small substrate made of elements such as resistors and capacitors, and parts combined with single-sided / double-sided boards including a microcomputer and mechanical mechanisms are included in the electrical component.

The battery 150 receives external power and internal power, and supplies power to each component included in the vehicle. The battery 150 is a storage battery. The battery 150 is composed of positive and negative electrode plates and an electrolytic solution. A power source can be generated by generating DC power by a chemical action.

When the driver depresses the brake, electric power is generated by the motor. More specifically, when the current supplied to the motor is cut off, the vehicle turns the motor when the vehicle runs on the road. A current is generated in the motor which is driven by inertia of the vehicle, and the battery 150 is charged by the generated current.

Hereinafter, a method of performing braking control in a vehicle having the above-described components will be described in detail with reference to the accompanying drawings.

2 is a flowchart for explaining a braking control method of a vehicle according to the present invention.

First, the step of receiving the braking command proceeds (S310).

The vehicle is provided with accessories for guiding the driver's operation. For example, a steering apparatus such as a steering wheel, a brake pedal for generating a brake command, an accelerator pedal for generating an acceleration command, and the like may be installed in the undercarriage as an accessory. When a user input is applied to the brake pedal, a braking command is generated based on the strength of the user input or the like.

In addition to the displacement of the brake pedal, braking commands can be generated by displacement of the accelerator pedal, user input to the gear knob, user input to the paddle shift, and the like.

On the other hand, the generated braking command includes a braking amount to be braked by the vehicle. For example, the amount of braking can be increased or decreased according to the intensity of the user input applied to the brake pedal.

Next, in response to the braking command, a step of measuring the state of the battery mounted on the vehicle is performed (S320). When the vehicle receives a brake command, it determines whether the battery is in a regenerative braking state. To this end, the vehicle measures the state of the battery when the braking command is received, determines whether the braking is possible, or measures the state of the battery periodically or irregularly regardless of the braking command, It is possible to judge whether or not it is possible.

Depending on the measured state of the battery, the vehicle performs braking using regenerative braking or using a braking resistor. More specifically, if the measured state of the battery meets a predetermined criterion, the braking is performed using the regenerative braking (S330). If the measured state of the battery does not satisfy the preset reference , And performs the braking using the braking resistor (S340).

Here, the state of the battery is associated with at least one of the charge amount of the battery, the temperature of the battery, and the chargeability of the battery. More specifically, the predetermined condition is a state in which the measured battery state is capable of regenerative braking, and when the charged amount of the battery is higher than the reference amount, the battery temperature is higher than the reference maximum temperature, Or the battery is in a non-chargeable state, the predetermined condition is regarded as satisfied. In this case, regenerative braking is not performed, and braking is performed by the braking resistor.

On the other hand, braking using regenerative braking and braking resistance can be used in combination. More specifically, when the braking command is received, the vehicle according to the present invention compares the braking amount (or braking demand amount) included in the braking command with the regenerative braking allowable amount. Even when regenerative braking is possible, only regenerative braking can be used, or braking using regenerative braking and braking resistance can be used at the same time. For example, in a situation where regenerative braking is possible, only regenerative braking is performed when the braking amount included in the braking command is smaller than the regenerative braking amount. For another example, when the braking amount included in the braking command is larger than the regenerative braking allowable amount in the situation where the regenerative braking is possible, braking using the braking resistor is performed considering the difference between the regenerative braking allowable amount and the braking amount. To this end, the vehicle compares the back electromotive force generated in the motor and the reference electromotive force during regenerative braking (S350). If the result of the comparison is that the counter electromotive force is larger than the reference electromotive force, braking using the braking resistor is performed (S340).

On the other hand, when the braking command is received for the first time, the state of the battery does not satisfy the predetermined condition and can be converted into a state that satisfies predetermined conditions while the braking command is received. In this case, the vehicle may perform braking by operating the braking resistor in response to the braking command, and may perform braking using regenerative braking in place of the braking resistor in response to the state change of the battery.

On the other hand, when a load larger than the reference is applied to the braking resistor in a state where the braking resistor is operated, the vehicle according to the present invention can perform braking using not only the braking resistor but also the main brake applied to the vehicle. That is, when the braking demand is larger than the input limit value of the braking resistor, the motive brake is actuated to cope with the braking demand. To this end, the vehicle compares the back electromotive force generated in the motor with the reference electromotive force during braking using the braking resistor (S360). If the counter electromotive force is larger than the reference electromotive force as a result of comparison, the motive brake is actuated in a case where the braking resistance is greater than the input limit value of the braking resistor (S370). That is, since the main brake is used only in some situations, it is possible to minimize the problems such as the wear of the brake.

As described above, according to the present invention, not only the braking resistor but also the regenerative braking and the main brake are used together to perform control related to braking. In the case of conventional hybrid and electric vehicles, when the regenerative braking is possible or impossible, the driver feels a sense of heterogeneity due to the different braking force when the driver depresses the brake pedal. According to the present invention, the same braking force as the regenerative braking force It is possible to reduce the possibility of accidents because it always exhibits the same braking force as that predicted by the driver. In this case, when regeneration braking is used primarily to improve fuel economy, but when the engine is in an area beyond the input range of regenerative braking, braking is performed using a braking resistor to reduce the frequency of use of the brake motors and increase the life of the brake parts have. In addition, at the time of rapid braking, the regenerative braking and the main braking can be operated together with a higher braking force.

On the other hand, at the time of high-speed traveling, the braking force of the general vehicle is constant, while the kinetic energy is increased to the square, so that the braking distance is further increased. In the case of high-speed driving, the back-EMF voltage applied from the motor is high, which means that when the braking resistor is used for braking, the braking force can be further increased in proportion to the vehicle speed. In particular, in the case of a wheeled vehicle, since the grounding area is small, when the braking force is excessively high, the tire slip occurs. Therefore, there is a limit to shortening the braking distance. However, when applied to a tracked vehicle, The vehicle can be decelerated at a shorter distance when it is moving at high speed and performing a rapid deceleration.

FIG. 3 is a block diagram for explaining a configuration of a control unit of a vehicle according to the present invention, and FIG. 4 is a conceptual diagram for more specifically explaining contents related to a motor inverter of a vehicle according to the present invention.

Referring to FIG. 3, the control unit 300 in the vehicle includes a brake control unit 310. The braking control unit 310 includes a regenerative braking control unit 312, a brake control unit 314, and a braking resistor control unit 110.

The regenerative braking control unit 312 performs control related to regenerative braking, the brake control unit 314 performs control related to the brake, and the braking resistor control unit 110 performs control using the braking resistor. The regenerative braking control unit 312, the brake control unit 314, and the braking resistor control unit 110 perform controls assigned to them. However, in an exceptional situation in which a user input is applied to the forcible braking switch 170, the braking resistor control unit 110 may control or control other control units.

The braking resistor control unit 110 may be divided into a normal operation mode and an emergency operation mode. The normal operation mode is a mode operated in a normal vehicle running state in which there is no problem in the vehicle itself and the control unit 300, and is a flow of the braking control method described above with reference to Fig.

On the other hand, the emergency operation mode can be executed under certain conditions. The specific conditions may include when the motor inverter fails but at least one of the other controllers is faulty and the motor inverter fails.

Here, the controller includes a hybrid control unit (HCU), an engine control unit (ECU), a generator control unit (GCU), a motor control unit (MCU), a battery control unit (BMS) : Battery Management System).

Meanwhile, a separate algorithm or apparatus for determining whether the specific condition is satisfied may be provided in the vehicle, and the emergency operation mode is automatically executed when the specific condition is satisfied.

If the motor inverter has not failed and at least one of the other controllers has an error, the motor inverter is not in trouble, so that the command of the braking resistor control unit 110 is the command of the other controllers A circuit or software is configured so as to have a higher priority. At this time, since the normal control of the vehicle is impossible due to an abnormality of other controllers, the braking resistor control unit 110 operates the braking resistor to decelerate the vehicle. If at least one of the motor and the motor inverter is installed for each wheel or axle, the dynamic characteristics of the vehicle speed, acceleration, and rolling can be tracked in real time and the slip of the tire can be grasped have. At this time, the braking resistor control unit 110 simulates the function of the vehicle dynamic stability control apparatus such as vehicle dynamic control (VDC) and electronic stability program (ESP), so that the braking resistance The braking force of the engine 140 can be controlled.

As another example in which the emergency operation mode is executed, the motor inverter may fail. The emergency operation mode is executed when it is determined that the motor inverter fails or the signal or voltage from the motor inverter 122 is not normal. This will be described in detail with reference to FIG.

Referring to FIG. 4, the motor inverter 122 includes an inverting circuit 124 and a backup circuit 126 for performing a normal operation. The backup circuit 126 bypasses the inverting circuit 124 and is directly connected to the motor 120. If the motor inverter fails, the backup circuit 126 is activated and the inverter circuit 124 is shut off. The backup circuit 126 directs the motor 120 and the circuit line 180 directly to the backup circuit 126 for direct connection to the high voltage line 180 of the DC component, ) Includes a circuit that converts AC to DC. At this time, when the DC voltage is constant or the circuit is configured to lower the voltage deviation, it may be constituted simply because it causes an increase in the cost more than necessary.

On the other hand, when the emergency operation mode is operated, the emergency switch unit 190 can be operated. For example, in the normal operation mode, the emergency switching unit 190 connects the motor 120 to the inverting circuit 124, but in the emergency operation mode, the emergency switching unit 190 connects the motor 120 to the backup circuit 126 ). For example, in the emergency operation mode, the emergency swing unit 190 may disconnect the motor inverter 122 from the electrical component to prevent the electric component from being damaged by the back electromotive force of the motor 120. [

On the other hand, the DC reverse electromotive force converted by the motor inverter 122 may be different in voltage depending on the number of revolutions of the motor. If the voltage is within the internal pressure range of the controllers, the circuit to the controller is normally maintained, A current blocking component 192 such as a fuse or a diode may be installed so that the circuit can be disconnected. As a result, each of the electric components can control the vehicle as much as possible, while suppressing the failure of the electric components and reducing the speed and stopping the vehicle within the range of the internal pressure.

The vehicle according to the present invention is a vehicle that uses power generated by a motor. When a braking intention of the driver is perceived by the vehicle control unit, Excessively low or high, or (3) the battery can not be charged or discharged due to other causes, the vehicle can be braked using the braking resistor without performing regenerative braking.

When performing a braking operation using the braking resistor in the braking resistor control unit in the vehicle control unit, the braking resistor control unit increases the braking force of the braking resistor to reduce the input load of the braking resistor when an excessive load is applied to the braking resistor.

Apart from controlling whether the braking resistor is operated, the driver can operate the braking resistor by operating the forced braking switch.

On the other hand, ① when the back electromotive force supplied from the motor exceeds the internal pressure range of the electric parts, ② when the abnormality of main motive brake, ③ vehicle steering device, ④ECU etc. is detected, the braking resistance control section ③ notify the vehicle controller or the driver whether the braking resistor is working, ③ lower the regenerative braking prohibition command to the motor inverter control unit or high voltage battery control unit, ④ cut off the current path to the high voltage battery by the braking resistor control unit have.

When the driver operates the forced braking switch to activate the circuit to the braking resistor, only the braking resistor and some electrical components are connected to the motor inverter in the circuit line to which the motor inverter is connected, and other electrical components are disconnected from the electrical connection have.

The vehicle according to the present invention may be provided with a braking input section in the form of a paddle shift or a gear knob, as in a normal vehicle. When the driver changes the operation mode of the parts and intends to forcibly decelerate the vehicle is recognized, the braking resistor is operated to simulate the engine brake effect to decelerate the vehicle, change the mode of the braking input part, The size of the engine brake effect may also be adjustable. Apart from braking by the braking input section, the driver can additionally control the braking force by stepping on the brake pedal.

The forcible brake switch may be provided as a separate switch, or may be a software switch. More specifically, it means a software switch for not activating a separate switch but activating the braking resistor when it is determined that the driver does not decelerate the vehicle despite the fact that the driver is pressing the brake, . That is, even if a separate switch is not provided, the function corresponding to the forced braking switch can be automatically executed according to the state of the vehicle.

In order to judge that the vehicle is not decelerating despite the fact that the brake pedal is depressed, it is necessary to use ① a conventional vehicle speed sensor, ② a separate sensor or signal transmission circuit to obtain brake pedal displacement signal and vehicle speed or deceleration information ③ Vehicle deceleration information can be confirmed by receiving the information of a vehicle speed sensor such as a wheel speed sensor or a navigation GPS information value or an acceleration sensor such as a smart phone or a tablet PC and a GPS chip.

When the braking resistor is operated and the vehicle electrical components are also subjected to a high voltage, the vehicle according to the present invention can change the alternating speed on / off of the circuit to the braking resistor for power delivery to the braking resistor, The input impedance of the braking resistor can be adjusted to change the amount of transmission to the braking resistor.

In a vehicle designed to selectively control the acceleration / deceleration of a tire through a plurality of motors and inverters instead of corresponding to all axles or tires, the vehicle driving motor recognizes the state of the road surface and determines whether or not each tire can slip The motor inverter corresponding to each tire is controlled so that the slip of the tire does not occur, and kinetic energy can be recovered by an energy storage device such as a battery or a braking resistor if necessary.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

The present invention described above can be implemented as computer readable codes on a medium on which a program is recorded. The computer readable medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of the computer-readable medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and also implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer may include a braking resistor control unit 110 of the vehicle.

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (16)

A braking control method for a vehicle, which uses regenerative braking using power generated by a motor,
Receiving a braking command;
Measuring a state of a battery provided in the vehicle in response to the braking command;
Performing braking selectively using the regenerative braking based on the measured state of the battery or using a braking resistor provided in the vehicle; And
And disconnecting the electric connection between the motor and the electric component when the counter electromotive force supplied from the motor exceeds the internal pressure range of the electric component during braking using the braking resistor. The method according to claim 1,
The step of selectively performing the braking based on the measured state of the battery includes:
Performing the braking using the regenerative braking if the measured state of the battery meets a predetermined criterion; And
And performing the braking using the braking resistor when the measured state of the battery does not satisfy the preset reference. 3. The method of claim 2,
Wherein the predetermined condition is related to at least one of a charge amount of the battery, a temperature of the battery, and a chargeability of the battery. 3. The method of claim 2,
Further comprising the step of performing the braking using the braking resistor as well as the brakes provided in the vehicle when a load greater than a reference is applied to the braking resistor. 3. The method of claim 2,
Wherein the braking command includes a braking amount to be braked,
Wherein the step of performing the braking using the braking resistor comprises:
Further comprising the step of controlling on / off of a switch for transmitting or blocking power generated by the motor to the braking resistor based on the braking amount. 6. The method of claim 5,
Wherein at least one of an on / off period and a speed of the switch unit is varied according to the amount of the braking. The method according to claim 6,
Stopping the transmission of the electric power generated by the motor to the braking resistor when the braking according to the braking command is terminated and adjusting the switch unit to charge the battery by the electric power generated by the motor And the braking force of the vehicle. 3. The method of claim 2,
Wherein the braking command includes a braking amount to be braked,
Wherein the step of performing the braking using the braking resistor comprises:
And adjusting an impedance value of the braking resistor based on the braking amount. 9. The method according to claim 5 or 8,
Wherein the amount of power flowing in at least one of the battery and the braking resistor varies in real time according to the braking amount. The method according to claim 1,
The vehicle further includes a forcible brake switch configured to perform forcible braking until the vehicle is stopped,
Receiving a user input in the forcible brake switch; And
And performing braking using the braking resistor in response to the received user input. delete The method according to claim 1,
Wherein the vehicle has a braking input portion including at least one of a paddle shift, a gear knob, and a brake pedal,
Further comprising the step of performing braking using the braking resistor regardless of the measured state of the battery when a user input is applied to the vehicle operation unit. 13. The method of claim 12,
Wherein the step of performing braking using the braking resistor when a user input is applied to the braking input unit comprises:
Selecting one of a plurality of braking modes for defining a maximum speed based on a user input applied to the braking input unit; And
And performing braking at a speed defined in any one of the selected braking modes using the braking resistor. 13. The method of claim 12,
Further comprising braking by the braking resistor by a user input applied to the braking input unit and adjusting an additional braking force based on a user input applied to a brake pedal provided in the vehicle A method of braking a vehicle. The method according to claim 1,
Performing braking using at least one of the regenerative braking and the main brake applied to the vehicle when a user input is applied to the brake pedal provided in the vehicle;
Further comprising the step of performing braking using the braking resistor regardless of the state of the battery if the deceleration by at least one of the braking resistors does not satisfy a predetermined deceleration criterion. 16. The method of claim 15,
Further comprising the step of detecting a deceleration by the at least one vehicle using a separate speed sensing sensor capable of transmitting / receiving information with the vehicle or a displacement sensor of a brake pedal provided in the vehicle A method of braking a vehicle.

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