CN108798963B - Starting system based on fuel engine and automobile - Google Patents

Abstract

A fuel engine-based starting system and vehicle, the system comprising: the starting system controller is respectively connected with the super capacitor and the unidirectional DC/DC converter, the unidirectional DC/DC converter is controlled to be switched on or switched off according to a starting signal for starting the starter and the output voltage of the super capacitor, and when the unidirectional DC/DC converter is switched on, the unidirectional DC/DC converter performs voltage conversion on the output voltage of the super capacitor and then supplies power to the starter. The scheme of the invention can effectively manage the energy stored by the super capacitor, is beneficial to prolonging the power supply time of the super capacitor when the starter is started, and reduces the chance that the storage battery supplies power to the starter independently, thereby prolonging the service life of the storage battery.

Description

Starting system based on fuel engine and automobile

Technical Field

The invention relates to the technical field of starting of automobiles, in particular to a starting system based on a fuel engine and an automobile.

Background

With the continuous and rapid development of economy in China, the automobile industry is increasingly prosperous. At present, the automobiles on the market mainly take fuel oil automobiles as main power, and the fuel oil automobiles provide power through fuel oil engines, including gasoline engines and diesel engines.

A common starting method for a fuel engine is starting with a starter, and when a driving gear on a starter shaft is engaged with a ring gear on the periphery of an engine flywheel, electromagnetic torque generated by rotation of the starter is transmitted to a crankshaft of the engine through the flywheel, so that the fuel engine is started.

Most of existing starters adopt a storage battery as an energy supply unit, but the storage battery is damaged by large-current impact in the starting process. This is because, at the initial moment of starting, the starter does not generate induced potential, resulting in extremely large current at the starting moment, and the battery discharges with large current for a long time, resulting in excessive polarization of the battery plate, and further greatly shortening the service life.

The above problems are more prominent with the development of start-stop systems. Specifically, since the engine is idling for a considerable portion of the time while the vehicle is running, about 5% of the fuel consumption is in the idling state, and the start-stop system is developed to reduce the fuel consumption and the emission. Specifically, when the automobile waits for a signal lamp or stops traffic, the engine is automatically turned off; when the vehicle is going to continue running, the clutch pedal is depressed or the brake pedal is released, and the engine is immediately restarted. By adjusting the start-stop system, the fuel consumption and the exhaust emission generated under the idling condition of the automobile are reduced. In addition, when an automobile driver releases an accelerator pedal or brakes to decelerate the automobile, the redundant energy is generated and is usually changed into heat to be dissipated in the air, the braking energy is recovered, and the part of energy is reused through a generator to charge a storage battery in the automobile braking process, so that the fuel economy of the automobile is improved.

Due to the application of the start-stop system, the starting times and frequency of the automobile are increased, so that the charging and discharging frequency of the storage battery is correspondingly increased, and the service life of the storage battery is reduced to a greater extent. And because the storage battery has limited and very compact arrangement space, the heat is accumulated by frequent charging and discharging, and the storage battery is exposed in a high-temperature environment to cause high-temperature failure. Further, when the battery is charging other electrical loads, it will also affect other electrical loads and the vehicle electrical system.

Supercapacitors are expected to replace batteries as another energy supply unit. The super capacitor has the advantages of high charge-discharge efficiency (up to 99%), long cycle life (up to 100 ten thousand times), wide temperature application range (minus 40-65 ℃) and capability of efficiently utilizing transient brake feedback power. However, compared with a storage battery, the capacity of the super capacitor is small, and the energy of single charge and discharge is limited, so that the capacity is limited when the continuous high-intensity braking energy recovery is faced. In order to take advantage of the advantages of the storage battery and the super capacitor into account, there is a scheme in the prior art that the storage battery and the super capacitor are used together, for example, the storage battery and the super capacitor are connected in parallel in a composite energy storage technology, so as to provide a starting energy source for the starter and recover braking energy.

However, in the prior art, the problem that the service life of the storage battery is influenced due to the fact that the storage battery supplies power to the engine with large current independently because the super capacitor supplies power insufficiently when the automobile is started easily occurs. This is because the output voltage of the super capacitor will gradually decrease with the output of the electric energy during the energy supply process until the output voltage decreases to the lower limit value (for example, 8V) of the working voltage, and the super capacitor has to be stopped to supply power to the outside in order to protect the engine, the super capacitor and other electrical loads from the low voltage.

Disclosure of Invention

The invention solves the technical problem of providing a starting system based on a fuel engine and an automobile, controlling the one-way DC/DC converter to be switched on or off according to the output voltage of a super capacitor, effectively managing the energy stored by the super capacitor, being beneficial to prolonging the power supply time of the super capacitor when a starter is started, reducing the chance that a storage battery supplies power to the starter independently and prolonging the service life of the storage battery.

In order to solve the technical problem, an embodiment of the present invention provides a starting system based on a fuel engine, where the starting system includes a super capacitor, a unidirectional DC/DC converter, a generator, a starter, and a starting system controller, where a first end of the super capacitor is connected to a first end of the starter, a second end of the super capacitor is connected to a first end of the unidirectional DC/DC converter, and a second end of the unidirectional DC/DC converter is connected to a second end of the starter; the generator is connected with the super capacitor in parallel and is suitable for charging the super capacitor; the starting system controller is respectively connected with the super capacitor and the unidirectional DC/DC converter, the unidirectional DC/DC converter is controlled to be switched on or switched off according to a starting signal for starting the starter and the output voltage of the super capacitor, and when the unidirectional DC/DC converter is switched on, the unidirectional DC/DC converter performs voltage conversion on the output voltage of the super capacitor and then supplies power to the starter.

Optionally, the starting system controller comprises: a receiving unit adapted to receive the start signal; the comparison unit is suitable for receiving the output voltage of the super capacitor and comparing the output voltage with a preset voltage lower limit value and a preset voltage threshold value, wherein the preset voltage threshold value is higher than the preset voltage lower limit value; and the control unit controls the one-way DC/DC converter to be switched on or switched off according to the comparison result of the comparison unit and the starting signal.

Optionally, when the output voltage of the super capacitor is higher than the lower limit value of the preset voltage and lower than the preset voltage threshold, if the receiving unit receives the start signal, the control unit controls the unidirectional DC/DC converter to be turned on, otherwise, the control unit controls the unidirectional DC/DC converter to be turned off.

Optionally, in response to that the voltage output by the super capacitor is lower than a preset voltage lower limit value, the control unit controls the unidirectional DC/DC converter to be turned off.

Optionally, the embodiment of the present invention further includes a first switch, a first end of which is connected to the second end of the super capacitor, a second end of which is connected to the second end of the unidirectional DC/DC converter, a control end of the first switch is controlled by the control unit, and in response to that the output voltage of the super capacitor is higher than the preset voltage threshold, the control unit controls the first switch to be turned on, so that the super capacitor supplies power to the starter through the first switch.

Optionally, the first switch comprises an electronic relay.

Optionally, the embodiment of the present invention further includes a storage battery, wherein a first end of the storage battery is connected to a first end of the starter, and a second end of the storage battery is connected to a second end of the starter.

Optionally, when the first switch is turned on, the generator charges the battery via the first switch.

Optionally, the embodiment of the present invention further includes a second switch, the second end of the battery is connected to the second end of the starter through the second switch, a control end of the second switch is controlled by the control unit, and when the second switch is turned on, the battery supplies power to the starter through the second switch.

Optionally, when the first switch and the second switch are turned on, the generator charges the battery via the first switch and the second switch.

Optionally, the second switch comprises an electronic relay.

Optionally, the embodiment of the present invention further includes an electrical load, a first end of the electrical load is connected to the first end of the starter, a second end of the electrical load is connected to the second end of the starter, and the super capacitor supplies power to the electrical load through the first switch.

In order to solve the technical problem, an embodiment of the invention further provides an automobile, which comprises the starting system based on the fuel engine.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

the embodiment of the invention provides a starting system based on a fuel engine, which can comprise a super capacitor, a one-way DC/DC converter, a generator, a starter and a starting system controller, wherein the first end of the super capacitor is connected with the first end of the starter, the second end of the super capacitor is connected with the first end of the one-way DC/DC converter, and the second end of the one-way DC/DC converter is connected with the second end of the starter; the generator is connected with the super capacitor in parallel and is suitable for charging the super capacitor; the starting system controller is respectively connected with the super capacitor and the unidirectional DC/DC converter, the unidirectional DC/DC converter is controlled to be switched on or switched off according to a starting signal for starting the starter and the output voltage of the super capacitor, and when the unidirectional DC/DC converter is switched on, the unidirectional DC/DC converter performs voltage conversion on the output voltage of the super capacitor and then supplies power to the starter. By adopting the embodiment of the invention, the one-way DC/DC converter is controlled to be switched on or switched off according to the output voltage of the super capacitor, the energy stored by the super capacitor can be effectively managed, the power supply time of the super capacitor when the starter is started can be prolonged, the super capacitor can be utilized to have the excellent performance of rapid charging and discharging of large current, and the opportunity that the storage battery supplies power to the starter independently when the starter is started is reduced, so that the impact of the large current on the storage battery is avoided, and the service life of the storage battery is prolonged.

Further, the embodiment of the invention adopts the unidirectional DC/DC converter to perform voltage conversion on the output voltage of the super capacitor, so that the super capacitor realizes external power supply after passing through the unidirectional DC/DC converter, and stable output of working voltage can be realized. Specifically, the output voltage of the super capacitor is gradually reduced along with the output of the electric energy, and in order to realize constant voltage maintenance, the variable direct current voltage can be converted into the fixed direct current voltage through the unidirectional DC/DC converter, so that the electric system and the electric load of the whole vehicle are protected.

Furthermore, the energy supply ratio of the super capacitor and the storage battery can be adjusted according to the output voltage of the super capacitor by controlling the one-way DC/DC converter and the switching device in the starting system. When the output voltage of the super capacitor is higher, the super capacitor is preferentially used, so that space is provided for recovering braking energy in the braking process of the automobile, and the fuel economy of the whole automobile is improved.

Drawings

FIG. 1 is a schematic block diagram of a fuel engine-based starting system according to an embodiment of the present invention;

FIG. 2 is a schematic block diagram of another fuel engine-based starting system in an embodiment of the present invention;

FIG. 3 is a schematic block diagram of a fuel engine-based starting system according to still another embodiment of the present invention;

FIG. 4 is a schematic block diagram of a further fuel engine-based starting system in an embodiment of the present invention;

FIG. 5 is a flow chart of a method of controlling engine shutdown in a start stop system in an embodiment of the present invention;

FIG. 6 is a flowchart of a method of controlling engine starting in a start stop system in an embodiment of the present invention.

Detailed Description

As described in the background section, in the prior art, when a storage battery and a super capacitor are connected to provide a starting energy source for a starter, a situation that the storage battery supplies a large current to an engine alone due to insufficient energy supply of the super capacitor when an automobile is started frequently occurs, and further, the service life of the storage battery is reduced due to frequent charging and discharging.

The inventor of the present invention has found through research that the key of the above problem is that no limitation is set on the energy supply condition and the energy supply object of the super capacitor in the prior art, and it is impossible to ensure that the working voltage of the super capacitor is within the operable range when the super capacitor is required to work.

The embodiment of the invention provides a starting system based on a fuel engine, which can comprise a super capacitor, a one-way DC/DC converter, a generator, a starter and a starting system controller, wherein the first end of the super capacitor is connected with the first end of the starter, the second end of the super capacitor is connected with the first end of the one-way DC/DC converter, and the second end of the one-way DC/DC converter is connected with the second end of the starter; the generator is connected with the super capacitor in parallel and is suitable for charging the super capacitor; the starting system controller is respectively connected with the super capacitor and the unidirectional DC/DC converter, the unidirectional DC/DC converter is controlled to be switched on or switched off according to a starting signal for starting the starter and the output voltage of the super capacitor, and when the unidirectional DC/DC converter is switched on, the unidirectional DC/DC converter performs voltage conversion on the output voltage of the super capacitor and then supplies power to the starter. By adopting the embodiment of the invention, the one-way DC/DC converter is controlled to be switched on or switched off according to the output voltage of the super capacitor, so that when the working voltage of the super capacitor is reduced to the preset voltage threshold, the super capacitor is limited to supply power only to the starter under the condition that the starter is started, and not to supply power to other electrical loads, and the super capacitor does not supply power to the outside under the condition that the starter is not started. Therefore, the energy stored by the super capacitor is effectively managed, the power supply time of the super capacitor when the starter is started is prolonged, the super capacitor has the excellent performance of quick large-current charge and discharge, and the opportunity that the storage battery supplies power to the starter independently is reduced, so that the impact of large current on the storage battery is avoided, and the service life of the storage battery is prolonged.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Fig. 1 is a schematic block diagram of a fuel engine-based starting system in an embodiment of the present invention.

As shown in fig. 1, a fuel engine-based starting system 10 according to an embodiment of the present invention may include: a super capacitor 101, a unidirectional DC/DC converter 102, a generator 103, a starter 104, and a starting system controller 105.

A first end of the super capacitor 101 is connected to a first end of the starter 104, a second end of the super capacitor 101 is connected to a first end of the unidirectional DC/DC converter 102, and a second end of the unidirectional DC/DC converter 102 is connected to a second end of the starter 104.

In one implementation, a suitable capacity supercapacitor 101 may be used by estimating the required starting energy and recovered braking energy, and as a non-limiting example, 6 supercapacitor cells may be used in series, wherein each cell has a capacitance of 1200F, and a 200F supercapacitor is formed.

The unidirectional DC/DC converter 102, also referred to as a unidirectional Direct Current/Direct Current (DC/DC) converter, a switching power supply, or a switching regulator, can convert a DC voltage at an input terminal into a DC voltage with different voltage values at an output terminal when turned on, or convert a DC voltage with different input terminals into a constant DC voltage at an output terminal, and can cut off a Current when turned off. In the embodiment of the invention, the output voltage (8 v-15 v) in the working range of the super capacitor 101 can be converted into the constant voltage output, which is beneficial to protecting the starter 104, other electrical loads and the whole vehicle electrical system. As a non-limiting example, for a vehicle power system with a constant voltage requirement of 13.8V, a unidirectional DC/DC converter 102 with an input voltage ranging from 9V to 18V and a constant voltage of 13.8V obtained by conversion may be used.

The generator 103 is connected in parallel with the super capacitor 101 and is adapted to charge the super capacitor 101. Preferably, when the automobile brakes and decelerates, the generator 103 can charge the super capacitor 101 by using energy recovered by braking.

The starting system controller 105 is connected to the super capacitor 101 and the unidirectional DC/DC converter 102, and controls the unidirectional DC/DC converter 102 to be turned on or off according to a starting signal for starting the starter 104 and an output voltage of the super capacitor 101. When the unidirectional DC/DC converter 102 is turned on, the unidirectional DC/DC converter 102 performs voltage conversion on the output voltage of the super capacitor 101 and supplies power to the starter 104. When the unidirectional DC/DC converter 102 is turned off, the super capacitor 101 stops supplying power to the outside, and stores the remaining power.

In a specific implementation, the super capacitor 101, the unidirectional DC/DC converter 102, the generator 103 and the starter 104 may be connected by hard wires. The starting system controller 105 is connected to the super capacitor 101 and the unidirectional DC/DC converter 102 through a vehicle Controller Area Network (CAN), and acquires a starting signal for controlling the starting of the starter 104, a vehicle speed, a current and voltage signal of the super capacitor 101, a signal of the unidirectional DC/DC converter 102, a rotation speed signal of the generator 103 and the starter 104, and the like in the form of a vehicle body CAN signal.

In a specific implementation, the starting system controller 105 may include a receiving unit (not shown), a comparing unit (not shown), and a control unit (not shown). Wherein the receiving unit is adapted to receive the start signal. The comparing unit is suitable for receiving the output voltage of the super capacitor 101 and comparing the output voltage with a preset voltage lower limit value and a preset voltage threshold value, wherein the preset voltage threshold value is higher than the preset voltage lower limit value. The control unit is adapted to control the unidirectional DC/DC converter 102 to be turned on or off according to the comparison result of the comparison unit and the start signal.

The comparison unit may adopt a comparator, and the control unit may adopt a microcontroller, a programmable logic device, or the like. The embodiment of the present invention does not specially limit the specific implementation of the receiving unit, the comparing unit and the control unit.

Further, when the output voltage of the super capacitor 101 is higher than a preset voltage lower limit value and lower than a preset voltage threshold value, if the receiving unit receives the start signal, the control unit controls the one-way DC/DC converter 102 to be turned on, otherwise, the control unit controls the one-way DC/DC converter 102 to be turned off.

Specifically, the preset voltage threshold is set for limiting the power supply object of the super capacitor 101, and when the output voltage of the super capacitor 101 is above the preset voltage threshold, the super capacitor 101 may supply power to the entire vehicle electrical system and other electrical loads. When the output voltage of the super capacitor 101 is reduced to be lower than the preset voltage threshold, the super capacitor 101 reserves the residual capacity, and external power supply is suspended, so that when the super capacitor 101 is required to supply power to the starter 104, the working voltage of the super capacitor 101 is in a working range.

It can be understood that if the preset voltage threshold is set too high, the electric quantity retained by the super capacitor 101 is too much, and the super capacitor 101 cannot supply power to the electric system of the entire vehicle and other electric loads under the condition of sufficient electric quantity, so that the characteristic of high charging and discharging efficiency of the super capacitor 101 cannot be fully utilized, thereby causing resource waste. If the preset voltage threshold is set too low, the power retained by the super capacitor 101 is too low, and when the power is too low to supply to the starter 104 for starting, the power still has to be supplied to the starter 104 by a storage battery (not shown), so that the storage battery is not protected from large current impact.

As a non-limiting example, for a vehicle power system requiring a constant voltage of 13.8V, the preset voltage threshold may be set to 10V.

The preset voltage lower limit value is the working range lower limit value of the super capacitor 101, and is set for limiting the super capacitor 101 to supply power outside the working range. As a non-limiting example, the preset lower voltage limit may be set to 8V for a vehicle power system with a constant voltage requirement of 13.8V.

When the output voltage of the super capacitor 101 is higher than the lower limit value of the preset voltage and lower than the preset voltage threshold, the super capacitor 101 may supply power to the starter 104 only when the starter 104 is started, but not to supply power to other electrical loads. Therefore, the power supply time of the super capacitor 101 when the starter 104 is started is effectively prolonged, the excellent performance that the super capacitor 101 can be charged and discharged rapidly under large current is utilized, the chance that the storage battery supplies power to the starter 104 alone is reduced, the impact of the large current on the storage battery is avoided, and the service life of the storage battery is prolonged.

Further, in response to the voltage output by the super capacitor 101 being lower than a preset voltage lower limit value, the control unit controls the unidirectional DC/DC converter 102 to turn off.

Specifically, when the output voltage of the super capacitor 101 is reduced to the lower limit value of the working range, the super capacitor 101 is limited from supplying power to the outside in order to protect the electric system and other electric loads of the whole vehicle.

Fig. 2 is a schematic block diagram of another fuel engine-based starting system in the embodiment of the invention. As shown in fig. 2, a fuel engine-based starting system 20 according to an embodiment of the present invention may include: a super capacitor 201, a unidirectional DC/DC converter 202, a generator 203, a starter 204, a starting system controller 205, and a first switch 206.

Wherein, a first end of the first switch 206 is connected to a second end of the super capacitor 201, a second end of the first switch is connected to a second end of the unidirectional DC/DC converter 202, a control end of the first switch 206 is controlled by the control unit, and in response to that the output voltage of the super capacitor 201 is higher than a preset voltage threshold, the control unit controls the first switch 206 to be turned on, so that the super capacitor 201 supplies power to the starter 204 via the first switch 206.

Specifically, the super capacitor 201 can directly supply power to the starter 204 by the conduction of the first switch 206, so as to improve the power supply efficiency. This is because, although the unidirectional DC/DC converter 202 can function to make the super capacitor 201 output at a constant voltage, the energy loss caused by the current flowing through the unidirectional DC/DC converter 202, referring to the description of the unidirectional DC/DC converter 102 in fig. 1, as a non-limiting example, the input voltage range of the unidirectional DC/DC converter 102 is 9V to 18V, the converted constant voltage is 13.8V, and the operating efficiency is only 88% in the case of 100% load.

With continued reference to fig. 2, adjusting the supercapacitor 201 to supply power directly to the starter 204 by turning off the first switch 206 helps to achieve higher current, start faster, and efficiency.

Further, the first switch 206 is set to be turned on when the output voltage of the super capacitor 201 is higher than the preset voltage threshold, which helps to avoid direct external power supply when the electric quantity of the super capacitor 201 is insufficient, so that the electric system and the electric load of the whole vehicle are damaged.

The first switch 206 may be an electronic relay, a photocoupler, a thyristor switch, or the like.

In a specific implementation, the super capacitor 201, the unidirectional DC/DC converter 202, the generator 203, the starter 204 and the first switch 206 may be connected by hard wires. The starting system controller 205 is connected to the supercapacitor 201 and the unidirectional DC/DC converter 202 through CAN, and acquires a starting signal for controlling the starting of the starter 204, a vehicle speed, current and voltage signals of the supercapacitor 201, a signal of the unidirectional DC/DC converter 202, rotational speed signals of the generator 203 and the starter 204, a signal of the first switch 206, and the like in the form of a vehicle body CAN signal.

Still another fuel engine-based starting system 30 as shown in FIG. 3 may include: super capacitor 301, unidirectional DC/DC converter 302, generator 303, starter 304, starting system controller 305, first switch 306, battery 307.

A first end of the battery 307 is connected to a first end of the starter 304, and a second end of the battery 307 is connected to a second end of the starter 304.

In a specific implementation, the battery 307 may be connected to the starter 304 at all times to supply power to the starter 304. This is because, through the control of the unidirectional DC/DC converter 302 by the control unit, the super capacitor 301 can be controlled to supply power to the starter 304 in parallel with the storage battery 307 when the starter 304 is started, that is, the storage battery 307 is prevented from supplying power to the starter 304 alone, so that the possibility that a large current impacts the storage battery 307 is reduced.

When the first switch 306 is turned on, the generator 303 charges the battery 307 via the first switch 306.

In specific implementation, the generator 303 can be selected to charge the storage battery 307 or charge the super capacitor 301 by controlling the first switch 306, so that the energy supply ratio of the super capacitor 301 to the storage battery 307 is adjusted, and the fuel economy of the whole vehicle is improved by preferentially using the super capacitor 301 by utilizing the characteristic of high charging and discharging efficiency of the super capacitor 301. Furthermore, the characteristic that the storage battery 307 has large capacity and sufficient energy in single charge and discharge is utilized, and the storage battery 307 is utilized to recover the continuous high-intensity braking energy, so that a better recovery effect is achieved.

It should be noted that, in the embodiment of the present invention, the generator 303 with an output voltage that is not constant (for example, an output voltage of 10.6V to 16V) may be used. This is because the generator 303 can be controlled to charge the battery 307 only when the output voltage is higher than the voltage of the battery 307 by controlling the first switch 306. Specifically, the charging/discharging state of the battery 307 is automatically adjusted by the circuit voltage and the voltage state of the battery 307, and when the voltage of the battery 307 is lower than the circuit voltage, the battery 307 is charged, and otherwise, the battery is discharged. By controlling the first switch 306, frequent charging and discharging of the battery 307 due to a change in the output voltage of the generator 303 can be avoided.

Furthermore, the starting system 30 may further include a second switch 308, a second end of the battery 307 is connected to a second end of the starter 304 via the second switch 308, a control end of the second switch 308 is controlled by the control unit, and when the second switch 308 is turned on, the battery 307 supplies power to the starter 304 through the second switch 308.

In specific implementation, the second switch 308 can control the storage battery 307 to supply power to the starter 304. Specifically, the second switch 308 can be turned off when the electric quantity of the super capacitor 301 is sufficient, so that a large current is prevented from impacting the storage battery 307 when the starter 304 is started, and when the output voltage of the super capacitor 301 is high, the super capacitor 301 is preferentially used, so that a space is provided for recovering braking energy in the braking process of the automobile, and the fuel economy of the whole automobile is improved.

When the first switch 306 and the second switch 308 are turned on, the generator 303 charges the battery 307 via the first switch 306 and the second switch 308.

In a specific implementation, whether the generator 303 charges the storage battery 307 or not can be controlled by the first switch 306 and the second switch 308, for example, when the electric quantity of the storage battery 307 reaches a certain condition, the generator 303 can be selected to stop charging the storage battery 307, so that the generator 303 can supply power to the super capacitor 301 or the entire vehicle.

The second switch 308 may be an electronic relay, a photocoupler, a thyristor switch, or the like.

In a specific implementation, the super capacitor 301, the unidirectional DC/DC converter 302, the generator 303, the starter 304, the first switch 306, the storage battery 307, and the second switch 308 may be connected by hard wires. The starting system controller 305 is connected to the supercapacitor 301 and the unidirectional DC/DC converter 302 through CAN, and acquires a starting signal for controlling the starting of the starter 304, a vehicle speed, current and voltage signals of the supercapacitor 301, a signal of the unidirectional DC/DC converter 302, rotation speed signals of the generator 303 and the starter 304, a current and voltage signal of the battery 307, signals of the first switch 306 and the second switch 308, and the like in the form of a vehicle body CAN signal.

Still another fuel engine-based starting system 40 as shown in FIG. 4 may include: a super capacitor 401, a unidirectional DC/DC converter 402, a generator 403, a starter 404, a starting system controller 405, a first switch 406, and an electrical load 407.

Wherein, a first end of the electrical load 407 is connected to a first end of the starter 404, a second end of the electrical load 407 is connected to a second end of the starter 404, and the super capacitor 401 supplies power to the electrical load 407 via the first switch 406.

In a specific implementation, in response to the output voltage of the super capacitor 401 being higher than a preset voltage threshold, the control unit controls the first switch 406 to be turned on. Under the condition that the electric quantity of the super capacitor 401 is sufficient, the electric load 407 is supplied with power through the first switch 406, and the fuel economy of the whole vehicle is improved by preferentially using the super capacitor 401.

In a specific implementation, the super capacitor 401, the unidirectional DC/DC converter 402, the generator 403, the starter 404, the first switch 406, and the electrical load 407 may be connected by hard wires. The starting system controller 405 is connected to the super capacitor 401 and the unidirectional DC/DC converter 402 through CAN, and acquires a starting signal for controlling the starting of the starter 404, a vehicle speed, current and voltage signals of the super capacitor 401, a signal of the unidirectional DC/DC converter 402, rotation speed signals of the generator 403 and the starter 404, a signal of the first switch 406, and the like in the form of a vehicle body CAN signal.

The fuel engine-based starting systems 10, 20, 30 and 40 described in fig. 1 to 4 were simulated by building a simulation model, and the obtained results show that: after the embodiment of the invention is applied to a common vehicle type, the oil consumption is reduced by 4 percent at most.

An automobile is also disclosed that includes any of the fuel engine-based starting systems 10, 20, 30, and 40 of fig. 1-4.

It should be understood by those skilled in the art that the configuration of the fuel engine-based starting system is not limited to the specific configuration of the four starting systems 10, 20, 30 and 40 shown in fig. 1, 2, 3 and 4, but various equivalent modifications are possible.

Further, the fuel engine-based starting systems 10, 20, 30 and 40 described in fig. 1 to 4 may be applied to a start-stop system. Specifically, when the automobile is in an idling working condition, the engine is automatically closed according to the state of the automobile; when the travel is to be continued, the engine is immediately restarted in accordance with the operation of the driver. By adjusting the start-stop system, the aims of reducing fuel consumption and tail gas emission generated under the idling condition of the automobile and saving energy are fulfilled.

Specifically, the state of the vehicle should be comprehensively judged to determine whether the engine can be shut down or started. Specifically, when the driver has a start-stop intention and the vehicle satisfies the start-stop limiting condition, the engine may be controlled to be turned off or started. The start-stop intention can be obtained through the gear state, the steering wheel state, the opening state of a brake pedal and the opening state of an accelerator pedal of the vehicle; the start-stop limiting conditions include: the system comprises a main switch signal, a start-stop switch signal, a vehicle speed signal, an engine state signal, a water temperature signal, a super capacitor state signal, a battery state signal, an electrical demand state signal, an automobile safety signal and the like.

Referring to fig. 5, fig. 5 is a flowchart of a method for controlling engine shutdown in a start stop system according to an embodiment of the invention. The method of controlling engine shut-down may include the following steps S501 to S510:

step S501: the vehicle state is detected.

In particular implementations, the vehicle states include an engine State, a vehicle gear State, a brake pedal opening, a vehicle speed, an engine water temperature, a power of an electrical load being used, and a battery State of Charge (SOC).

The engine state is used for indicating that the engine is in an idling working condition or a non-idling working condition. Specifically, the engine is in an idle working condition, namely the engine is separated from a transmission system and an accelerator pedal is completely loosened, and the engine only overcomes the resistance of the engine and does not output work to the outside.

The vehicle gear state is used to indicate whether the vehicle is in neutral or not.

The brake pedal opening is used for indicating the stepping depth of the brake pedal, for example, the brake pedal opening can be expressed by a signal of 0-100%, 0 represents that the brake pedal is not stepped, and 100% represents that the brake pedal is stepped to the maximum opening.

The engine water temperature is used to indicate the temperature of the engine. Specifically, when the engine temperature is low, the cold start engine consumes a large amount of energy and is also highly damaging to the engine. In this case, it is not recommended to shut down the engine.

The power of the electric load in use is used for indicating whether the high-power electric appliance in use is in the automobile. Specifically, when the power of the electrical load being used is large, the storage battery and the super capacitor cannot meet the power demand. In this case, it is not recommended to shut down the engine.

The battery SOC is used for indicating the residual capacity of the battery. Specifically, when the remaining capacity of the battery is too low, it is not recommended to shut down the engine in order to avoid the danger of overdischarge of the battery.

Step S502: and judging whether the engine is in an idling state or not. When the judgment result is yes, step S503 may be performed; otherwise, step S501 may be executed.

In particular implementations, when the engine is in idle conditions, the prerequisite condition for shutting down the engine in the start-stop system is met, and the next detection can be performed. Otherwise, when the engine is not in the idling condition, the step of detecting the vehicle state should be returned to, and the detection is carried out again.

Step S503: and judging whether the vehicle gear is neutral or not. When the judgment result is yes, step S504 may be performed; otherwise, step S501 may be executed.

In specific implementation, when the vehicle gear is neutral, namely the gearbox and the driving wheels are completely separated, the engine does not output work to the driving wheels, the condition of turning off the engine is met, and the next detection can be carried out. On the contrary, when the vehicle gear is not in the neutral position, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

Step S504: and judging whether the opening degree of the brake pedal is greater than a first preset opening degree threshold value or not. When the determination result is yes, step S505 may be performed; otherwise, step S501 may be executed.

In a specific implementation, when the opening degree of the brake pedal is greater than the first preset opening degree threshold value, namely the brake pedal is pressed down, the condition that the engine is shut down is met, and the next detection can be carried out, wherein the condition that the vehicle is intentionally controlled to slow down or stop moving by the driver is represented. On the contrary, when the brake pedal is not depressed, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

As a non-limiting example, the first preset opening degree threshold of the brake pedal may be set to 95%.

Step S505: and judging whether the vehicle speed is lower than a first preset vehicle speed threshold value. When the judgment result is yes, step S506 may be performed; otherwise, step S501 may be executed.

In a specific implementation, when the vehicle speed is lower than the first preset vehicle speed threshold value, the vehicle is slowed down or stops moving, the condition of shutting down the engine is met, and the next detection can be carried out. Otherwise, when the vehicle speed is still high, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

As a non-limiting example, a first preset vehicle speed threshold may be set to 0.

Step S506: and judging whether the water temperature of the engine exceeds a preset temperature threshold value. When the judgment result is yes, step S507 may be performed; otherwise, step S501 may be executed.

In the specific implementation, the temperature of the engine is detected through the temperature of the engine water, when the temperature of the engine is higher, the energy consumption for starting the engine is smaller, the damage to the engine is smaller, the condition for closing the engine is met, and the next detection can be carried out. On the contrary, when the engine temperature is low, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

As a non-limiting example, the preset temperature threshold may be set at 46 ℃.

Step S507: it is determined whether the power of the electrical load being used is below a first preset power threshold. When the judgment result is yes, step S508 may be performed; otherwise, step S501 may be executed.

In specific implementation, when no working high-power electric appliance is arranged in the automobile, the storage battery and the super capacitor can be judged to possibly meet the electric demand of the automobile, so that the condition of turning off the engine can be considered to be met, and the next detection can be carried out. Otherwise, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

As a non-limiting example, the first preset power threshold may be set to 100W.

Step S508: and judging whether the SOC of the storage battery is larger than a first preset electric quantity threshold value. When the determination result is yes, step S509 may be performed; otherwise, step S501 may be executed.

In specific implementation, when the residual capacity of the storage battery is large, the storage battery and the super capacitor can be judged to possibly meet the electricity utilization requirement of the vehicle, and then the storage battery and the super capacitor are considered to meet the condition of turning off the engine, and the next detection can be carried out. Otherwise, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

As a non-limiting example, a first preset charge threshold may be set to a battery SOC of 0.5.

Step S509: and judging whether the driver does not operate the vehicle within the preset waiting time. When the determination result is yes, step S510 may be performed; otherwise, step S501 may be executed.

In a specific implementation, if the driver has an intention to turn off the engine and there is no operation on the vehicle for a preset time, it may be considered that the engine-off condition is satisfied, and the next detection may be made. Otherwise, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

As a non-limiting example, the preset wait time may be set to 3 s. The reason is that under urban road conditions, congestion is common, and the preset waiting time is set to avoid the situation that the starting and stopping are too frequent, the damage to the starting and stopping system parts is caused, and the driving experience is influenced.

Step S510: the engine is shut down.

In the embodiment of the invention, when the driver has the intention of turning off the engine and the vehicle meets the limiting condition of turning off the engine, the engine is controlled to be turned off, so that the fuel consumption and the emission can be remarkably reduced.

Referring to fig. 6, fig. 6 is a flowchart of a method for controlling engine starting in a start-stop system according to an embodiment of the present invention. The method of controlling engine start may include the following steps S601 to S611:

step S601: the vehicle state is detected.

In particular implementations, the vehicle states include a brake pedal opening, a vehicle gear state, a steering wheel state, power of an electrical load being used, a battery SOC, and a vehicle speed.

The opening degree of the brake pedal is used for indicating the stepping depth of the brake pedal, for example, the opening degree of the brake pedal can be expressed by a signal of 0-100%, 0 represents that the brake pedal is not stepped, and 100% represents that the brake pedal is stepped to the maximum opening degree.

The vehicle gear state is used to indicate whether the vehicle is in neutral or not.

The steering wheel state is used to indicate whether steering wheel rotation is detected, which represents an intentional engine start by the driver.

The power of the electric load in use is used for indicating whether the high-power electric appliance in use is in the automobile. Specifically, when the power of the electrical load being used is large, the storage battery and the super capacitor cannot meet the power demand. In this case, the engine should be started.

The battery SOC is used for indicating the residual capacity of the battery. Specifically, when the remaining capacity of the battery is too low, the engine should be started in order to avoid the danger of overdischarge of the battery.

Step S602: and judging whether the opening degree of the brake pedal is smaller than a second preset opening degree threshold value. When the judgment result is yes, step S608 may be performed; otherwise, step S603 may be performed.

In a specific implementation, when the brake pedal opening is smaller than the second preset opening threshold, namely the brake pedal is released, the intention of the driver to start the engine is represented, and preparation work before starting the engine should be directly carried out. Conversely, when the brake pedal is not released, other vehicle conditions may continue to be detected.

As a non-limiting example, the second preset opening degree threshold of the brake pedal may be set to 5%.

Step S603: and judging whether the vehicle gear is neutral or not. When the judgment result is yes, step S604 may be performed; otherwise, step S608 may be performed.

In a specific implementation, when the vehicle gear is neutral, i.e. the gearbox is completely disconnected from the drive wheels, the engine does not output work to the drive wheels, which does not represent that the driver intentionally starts the engine, and other vehicle states can be continuously detected. On the contrary, when the vehicle gear is not in the neutral position, the preparation work before starting the engine should be directly performed on behalf of the driver who intentionally starts the engine.

Step S604: and judging whether the rotation angle of the steering wheel is larger than a preset angle threshold value or not. When the judgment result is yes, step S608 may be performed; otherwise, step S605 may be executed.

When the steering wheel rotation is detected, it is necessary to start the engine on behalf of the driver who intentionally controls the vehicle motion, and preparation before starting the engine should be directly performed. Otherwise, when the steering wheel rotation is not detected, other vehicle states may continue to be detected.

As a non-limiting example, the preset angle threshold may be set at 3 degrees.

Step S605: it is determined whether the power of the electrical load being used is above a second preset power threshold. When the judgment result is yes, step S608 may be performed; otherwise, step S606 may be performed.

In specific implementation, when a working high-power electric appliance exists in an automobile, it can be judged that the storage battery and the super capacitor may not meet the electric demand of the automobile, and further the storage battery and the super capacitor are considered to need to be started by the engine, and preparation work before the engine is started should be directly carried out. On the contrary, the working high-power electric appliance is not detected, and other vehicle states can be continuously detected.

As a non-limiting example, the second preset power threshold may be set to 100W.

Step S606: and judging whether the SOC of the storage battery is smaller than a second preset electric quantity threshold value. When the judgment result is yes, step S608 may be performed; otherwise, step S607 may be executed.

In a specific implementation, when the remaining capacity of the storage battery is small, it can be judged that the storage battery and the super capacitor may not meet the electricity utilization requirement of the vehicle, and further it is considered that the engine needs to be started, and the preparation work before the engine is started should be directly performed. Otherwise, other vehicle states may continue to be detected.

As a non-limiting example, the second preset charge threshold may be set to a battery SOC of 0.3.

Step S607: and judging whether the vehicle speed is higher than a second preset vehicle speed threshold value. When the judgment result is yes, step S608 may be performed; otherwise, step S601 may be performed.

In particular implementations, when the vehicle speed is above the second preset vehicle speed threshold, it is representative that the vehicle is beginning to move or the coasting speed is increasing, the conditions for starting the engine are met, and preparatory work before starting the engine may be performed. Otherwise, when the vehicle speed is still low, the step of detecting the vehicle state should be returned to, and the detection should be performed again.

As a non-limiting example, the second preset vehicle speed threshold may be set to 0.

Step S608: and judging whether a safety problem exists or not. If the judgment result is yes, the engine is not suitable for being started, and the process is ended; otherwise, step S609 may be performed.

In particular implementations, safety issues are used to indicate whether starting the engine may affect driving safety, which may include, for example, whether the driver is present or whether the engine compartment cover is closed.

Step S609: and judging whether the output voltage of the super capacitor is greater than a preset voltage threshold value or not. When the judgment result is yes, step S610 may be performed; otherwise, step S611 may be performed.

Step S610: the super capacitor starts the engine.

Step S611: the battery starts the engine.

For further description of the super capacitor and battery powering the starter to start the engine, please refer to fig. 1-4 for the fuel engine-based starting systems 10, 20, 30, and 40, which will not be described herein.

In the embodiment of the invention, when the driver has the intention of starting the engine and the vehicle meets the limit condition of starting the engine, the engine should be controlled to start in time, so that the inconvenient driving feeling can be avoided.

Those skilled in the art will appreciate that all or part of the steps in the methods of the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer-readable storage medium, and the storage medium may include: ROM, RAM, magnetic or optical disks, and the like.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (11)

1. A fuel engine-based starting system, comprising a super capacitor, a unidirectional DC/DC converter, a generator, a starter and a starting system controller, wherein:

the first end of the super capacitor is connected with the first end of the starter, the second end of the super capacitor is connected with the first end of the unidirectional DC/DC converter, and the second end of the unidirectional DC/DC converter is connected with the second end of the starter;

the generator is connected with the super capacitor in parallel and is suitable for charging the super capacitor;

the starting system controller is respectively connected with the super capacitor and the unidirectional DC/DC converter, the unidirectional DC/DC converter is controlled to be switched on or switched off according to a starting signal for starting the starter and the output voltage of the super capacitor, and when the unidirectional DC/DC converter is switched on, the unidirectional DC/DC converter performs voltage conversion on the output voltage of the super capacitor and supplies power to the starter;

the starting system controller includes:

a receiving unit adapted to receive the start signal;

the comparison unit is suitable for receiving the output voltage of the super capacitor and comparing the output voltage with a preset voltage lower limit value and a preset voltage threshold value, wherein the preset voltage threshold value is higher than the preset voltage lower limit value;

the control unit is suitable for controlling the one-way DC/DC converter to be conducted when the output voltage is higher than the preset voltage threshold value, and the super capacitor is suitable for supplying power to a finished automobile electrical system and other electrical appliance loads; when the output voltage of the super capacitor is higher than the lower limit value of the preset voltage and lower than the threshold value of the preset voltage, if the receiving unit receives the starting signal, the control unit controls the one-way DC/DC converter to be conducted, and the super capacitor only supplies power to the starter.

2. The fuel engine-based starting system according to claim 1, wherein the control unit controls the unidirectional DC/DC converter to turn off in response to the voltage of the super capacitor output being lower than a preset voltage lower limit value.

3. The fuel engine-based starting system according to claim 1, further comprising: and a first switch, a first end of which is connected with the second end of the super capacitor, a second end of which is connected with the second end of the unidirectional DC/DC converter, a control end of the first switch is controlled by the control unit, and the control unit controls the first switch to be conducted in response to that the output voltage of the super capacitor is higher than the preset voltage threshold value, so that the super capacitor supplies power to the starter through the first switch.

4. A fuel engine-based starting system as claimed in claim 3, wherein said first switch comprises an electronic relay.

5. The fuel engine-based starting system according to claim 3, further comprising: the first end of the storage battery is connected with the first end of the starter, and the second end of the storage battery is connected with the second end of the starter.

6. The fuel engine-based starting system according to claim 5, wherein the generator charges the battery via the first switch when the first switch is turned on.

7. The fuel engine-based starting system according to claim 5, further comprising: the second end of the storage battery is connected with the second end of the starter through the second switch, the control end of the second switch is controlled by the control unit, and when the second switch is conducted, the storage battery supplies power to the starter through the second switch.

8. The fuel engine-based starting system according to claim 7, wherein the generator charges the battery via the first switch and the second switch when the first switch and the second switch are turned on.

9. The fuel engine-based starting system of claim 7, wherein the second switch comprises an electronic relay.

10. The fuel engine-based starting system according to claim 3, further comprising: the first end of the electric load is connected with the first end of the starter, the second end of the electric load is connected with the second end of the starter, and the super capacitor supplies power to the electric load through the first switch.

11. An automobile, characterized by comprising the fuel engine-based starting system according to any one of claims 1 to 10.

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