CN103600742B - A kind of hybrid vehicle energy management controls device and energy management control method - Google Patents

Abstract

A kind of hybrid vehicle energy management controls device and energy management control method, belongs to hybrid vehicle automatic control technology field. CAN data-interface is connected with data processing module; Data processing module solves module with object function and is connected; Object function solves module and is connected with CAN data-interface; CAN data-interface is connected with extraneous Engine ECU, motor MCU, change speed gear box TCU, battery BCU by CAN. The present invention also provides for a kind of hybrid vehicle energy management control method, the real-time moment of torsion of electromotor that the method is transmitted according to CAN interface, real-time rotating speed, battery real-time voltage, it is thus achieved that transient fuel consumption information, battery state of charge information, sets up object function; Solving equation, obtains the control strategy of whole operating mode. The present invention can make the low oil consumption of hybrid vehicle, low emission potentiality give full play of, it is achieved saves petroleum-based energy, environment protection and reduction of discharging requirement.

Description

Energy management control device and energy management control method for hybrid electric vehicle

Technical Field

The invention relates to an energy management control device and an energy management control method for a hybrid electric vehicle, and belongs to the technical field of automatic control.

Background

Along with the increasing global pollution and the gradual depletion of petroleum resources, the development of new energy vehicles, the reduction of pollutant emission and the reduction of petroleum consumption are urgent. With the change of life of people, the demand on automobiles is getting larger and larger, and how to achieve the purpose of energy conservation and emission reduction without reducing the performance of the automobiles becomes a research focus of various automobile research institutions. The energy management control method of the hybrid electric vehicle is the fundamental point for solving the problem.

The dynamic programming algorithm is a powerful tool for solving the dynamic optimization problem. The algorithm can meet global optimization and simultaneously process the constraint condition and nonlinearity of the solved problem. Defining policiesIs an optimization strategy for the following discrete dynamic optimization problem, whereinRefers to the state variable x_kUsing a controlled variable u_kA state value of (i), i.e. ${\mathrm{\μ}}_k^{*}=u_k\left(x_k\right).$

The cost function is: $J=G_N\left(x_N\right)+\underset{k=0}{\overset{N-1}{\Σ}}{L}_k(x_k,u_k,w_k)$

the state transition equation is: x is the number of_k+1＝f_k(x_k,u_k,w_k)，k＝0,1,……,N-1.

Wherein the state x_kBelonging to a state space X_k(ii) a Control variable u_kSubject to the constraints of a given space,w_krepresenting process noise.

Part of the same way strategyIs the optimal control strategy of the step length i-N cost function.

$G_N\left(x_N\right)+\underset{k=i}{\overset{N-1}{\Σ}}{L}_k(x_k,u_k,w_k)$

When the minimum value of the cost function is solved, the current sub-problem can be solved through the previous state, and the process is repeated circularly until all the cost functions are solved. With this idea, solving the cost function can be divided into a series of simple minimization problems as follows:

the step N-1:

$J_{N-1}^{*}\left(x_{N-1}\right)=\underset{u_{N-1}}{min}\[G\left(x_N\right)+L(x_{N-1},u_{N-1})\]$

the k step: k is more than or equal to 0 and less than or equal to N-1

$J_k^{*}\left(x_k\right)=\underset{u_k}{min}\[L(x_k,u_k)+J_{k+1}^{*}\left(x_{k+1}\right)\]$

WhereinRepresents the optimization function at step K.

Disclosure of Invention

The invention aims to solve the problem that the conventional hybrid electric vehicle is not sufficiently played in the aspects of energy conservation and emission reduction, and provides an energy management control device and an energy management control method for the hybrid electric vehicle.

The technical scheme of the invention is that,

a hybrid vehicle energy management control device comprises an energy management main controller, a CAN bus interface, a CAN bus, a first rotating speed torque sensor, a single chip microcomputer, a first A/D converter, an engine, a second rotating speed torque sensor, a second single chip microcomputer, a second A/D converter, a motor, a vehicle speed acquisition sensor, a third A/D converter, a third single chip microcomputer and a variable speed gear acquisition sensor; wherein,

the energy management main controller is formed by connecting a data processing module and an objective function solving control output module;

the CAN bus is respectively connected with a first single chip microcomputer, a second single chip microcomputer, a third single chip microcomputer, a fourth single chip microcomputer, a data processing module and an objective function solving control output module;

the first single chip microcomputer is respectively connected with the first rotating speed torque sensor and the first A/D converter;

the engine is respectively connected with a first rotating speed torque sensor and a first A/D converter;

the second singlechip is respectively connected with the second rotating speed torque sensor and the second A/D converter;

the motor is respectively connected with a second rotating speed torque sensor and a second A/D converter;

the third singlechip is respectively connected with the vehicle speed acquisition sensor, the third A/D converter and the speed change gear acquisition sensor;

the gearbox is respectively connected with a vehicle speed acquisition sensor, a third A/D converter and a speed change gear acquisition sensor.

The first single chip microcomputer, the second single chip microcomputer, the third single chip microcomputer and the fourth single chip microcomputer are all single chip microcomputers TC 1767.

The invention also provides a hybrid electric vehicle energy management control method, which comprises the following steps:

step 1: the first single chip microcomputer acquires the real-time rotating speed and the real-time torque of the engine through the first rotating speed torque sensor; the second single chip microcomputer acquires the real-time rotating speed and the real-time torque of the motor through a second rotating speed torque sensor;

the third singlechip acquires the gear of the real-time gearbox through a speed change gear acquisition sensor; the fourth singlechip obtains the voltage of the current battery through a battery voltage measuring circuit;

step 2: the first single chip microcomputer sends the acquired real-time rotating speed and real-time torque of the engine to the energy management main controller through the CAN bus; the second singlechip sends the acquired real-time rotating speed and real-time torque of the motor to the energy management main controller through a CAN bus;

the third singlechip sends the collected real-time gearbox gear to the energy management main controller through a CAN bus; the fourth singlechip sends the obtained current battery voltage to the energy management main controller through a CAN bus.

And step 3: the data processing module of the energy management main controller processes the real-time rotating speed and the real-time torque of the engine received from the CAN bus to obtain the instantaneous fuel consumption of the engine; processing the battery voltage received from the CAN bus to obtain the current battery charge state; receiving gear information from a CAN bus

And 4, step 4: the objective function solving control output module of the energy management main controller establishes a state variable of the battery charge state, the vehicle speed and the gear, a cost function of the battery charge state and the battery charge state, the maximum and the minimum of the engine torque, the engine rotating speed, the motor torque, the motor rotating speed and the battery charge state, and the minimum of the cost function as objective functions, and solves the objective function by using a dynamic programming method to obtain the control quantity of the motor output torque, so that the control quantity of the engine output torque is obtained.

And 5: the CAN bus transmits the engine output torque control quantity and the motor output torque control quantity obtained from the energy management main controller to the first singlechip and the second singlechip. The first single chip microcomputer and the second single chip microcomputer control the engine and the motor through the first A/D converter and the second A/D converter to complete the control process.

The invention has the beneficial effects that: the invention can optimally distribute the output torque of the engine and the motor, thereby improving the fuel economy of the engine. By the optimized control variable, the low oil consumption and the low emission potential of the hybrid electric vehicle are fully exerted, and the requirements of saving petroleum energy, protecting the atmospheric environment and reducing emission are met.

Drawings

FIG. 1 is a schematic view of the overall structure of the apparatus of the present invention.

FIG. 2 is a diagram illustrating the relationship between the state of charge and the voltage of the battery according to the present invention.

FIG. 3 is a schematic diagram showing the relationship between the internal charge-discharge resistance and the charge state of the battery according to the present invention.

Fig. 4 is a schematic diagram illustrating the effect of the embodiment of the present invention, wherein (a) is a diagram of the required torque distribution, and (b) is a diagram of the battery state of charge change.

Detailed Description

The technical solutions of the present invention will be further described below with reference to the accompanying drawings, and the present invention is not limited to these embodiments.

FIG. 1 is a schematic view of the overall structure of the apparatus of the present invention. As shown in fig. 1, the energy management control device for the hybrid electric vehicle comprises an energy management main controller, a CAN bus interface, a CAN bus, a first rotating speed torque sensor, a first single chip microcomputer, a first a/D converter, an engine, a second rotating speed torque sensor, a second single chip microcomputer, a second a/D converter, a motor, a vehicle speed acquisition sensor, a third a/D converter, a third single chip microcomputer, a gear shifting acquisition sensor, a battery voltage measurement circuit, a fourth single chip microcomputer and a fourth a/D converter; wherein,

the energy management main controller is formed by connecting a data processing module and an objective function solving control output module;

the CAN bus is respectively connected with a first single chip microcomputer, a second single chip microcomputer, a third single chip microcomputer, a fourth single chip microcomputer, a data processing module and an objective function solving control output module;

the first single chip microcomputer is respectively connected with the first rotating speed torque sensor and the first A/D converter;

the engine is respectively connected with a first rotating speed torque sensor and a first A/D converter;

the second singlechip is respectively connected with the second rotating speed torque sensor and the second A/D converter;

the motor is respectively connected with a second rotating speed torque sensor and a second A/D converter;

the third singlechip is respectively connected with the vehicle speed acquisition sensor, the third A/D converter and the speed change gear acquisition sensor;

the gearbox is respectively connected with a vehicle speed acquisition sensor, a third A/D converter and a speed change gear acquisition sensor;

the fourth singlechip is respectively connected with the battery voltage measuring circuit and the fourth A/D converter;

the battery is respectively connected with the battery voltage measuring circuit and the A/D converter No. four.

The first single chip microcomputer, the second single chip microcomputer, the third single chip microcomputer and the fourth single chip microcomputer are all single chip microcomputers TC 1767.

The energy management control method of the hybrid electric vehicle comprises the following steps:

step 1: the first single chip microcomputer acquires the real-time rotating speed and the real-time torque of the engine through the first rotating speed torque sensor; the second single chip microcomputer acquires the real-time rotating speed and the real-time torque of the motor through a second rotating speed torque sensor;

the third singlechip acquires the gear of the real-time gearbox through a speed change gear acquisition sensor; the fourth singlechip obtains the voltage of the current battery through a battery voltage measuring circuit;

step 2: the first single chip microcomputer sends the acquired real-time rotating speed and real-time torque of the engine to the energy management main controller through the CAN bus; the second singlechip sends the acquired real-time rotating speed and real-time torque of the motor to the energy management main controller through a CAN bus; the third singlechip sends the collected real-time gearbox gear to the energy management main controller through a CAN bus; the fourth singlechip sends the obtained current battery voltage to the energy management main controller through a CAN bus.

And step 3: the data processing module of the energy management main controller processes the real-time rotating speed and the real-time torque of the engine received from the CAN bus to obtain the instantaneous fuel consumption of the engine; processing the battery voltage received from the CAN bus to obtain the current battery charge state; and receiving gear information from the CAN bus.

And 4, step 4: the objective function solving control output module of the energy management main controller establishes a state variable of the battery charge state, the vehicle speed and the gear, a cost function of the battery charge state and the battery charge state, which are received from the data processing module, and solves the objective function by using the minimum value of the cost function as an objective function and the dynamic programming method to obtain the control quantity of the motor output torque so as to obtain the control quantity of the engine output torque;

the target function solving control output module receives the fuel consumption signal and the battery charge state signal transmitted by the data processing module, and establishes a target function with the fuel consumption and the battery charge state as the cost:

$J=G_N\left(x_N\right)+\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{L}_k(x_k,u_k)=\mathrm{\α}{({\mathrm{SOC}}_N-{\mathrm{SOC}}_f)}^2+\underset{k=0}{\overset{N-1}{\Σ}}\[{\mathrm{fuel}}_k\]$

wherein the SOC_fRepresenting the expected value of the battery state of charge at the end, α representing a positive weighting factor.

Specific fuel consumption W_fuelThe partial engine speed-engine torque-fuel consumption rate table may be obtained by a look-up table of engine speed and engine torque received from the data processing module as follows:

revolution per minute	Torque rice	Oil consumption per kilogram and kilowatt hour
			800	181	0.271892
800	172	0.238966
			800	151	0.226442
800	134	0.230482
			800	116	0.223614
800	95	0.222604
			800	76	0.23735
800	58	0.232502
			800	38	0.28381
800	18	0.345622
			1000	208	0.249874
1000	192	0.22523
			1000	167	0.228866
1000	147	0.229068
			1000	127	0.221998
1000	105	0.23028
			1000	84	0.250682
1000	63	0.250682
			1000	42	0.297344

The battery state of charge can be obtained by the following state-transfer equation:

${\mathrm{SOC}}_{k+1}={\mathrm{SOC}}_k-\frac{i_{b,k}}{Q_b},$

wherein i_bFor discharging current of battery, Q_bThe maximum discharge capacity of the battery. The cell discharge current is obtained by the following formula:

$i_{b,k}=\frac{V_{oc,k}-\sqrt{V_{oc,k}^2-4(R_{\mathrm{int},k}+R_t)\·P_{b,k}}}{2(R_{\mathrm{int},k}+R_t)},$

wherein, V_oc,kIs the current battery voltage, R_tIs the battery terminal impedance, R_intRepresenting the internal resistance of the battery, divided into discharge internal resistance R_int,dis(SOC), internal resistance of charging R_int,chg(SOC), each as a function of the state of charge of the battery. P_bRepresentative battery power is obtained by the following equation:

wherein, η_mThe motor efficiency can be obtained by looking up a table through the motor torque and the motor rotating speed.

The transmission output shaft torque can be obtained by:

τ_x＝R_xη_x(τ_t-τ_x,l)，

wherein R is_xη for the transmission ratio of the gearbox_xFor transmission efficiency, the table can be looked up; tau is_tOutputting torque for the torque coupler; tau is_x,lIs a transmission loss;

the drive torque at the wheels is then:

τ_d＝R_dη_d(τ_x+R_cτ_mη_c-τ_d,l)，

wherein R is_dAnd η_dTo be the gear ratios and gear rates,is a torque loss of the differential

The vehicle speed state transition equation is as follows:

$v_{v,k+1}=v_{v,k}+\frac{1}{M_r}(\frac{{\mathrm{\τ}}_{wh,k}}{r_d}-\frac{B_{wh}{v}_{v,k}}{r_d^2}-\frac{v_{v,k}}{\left|v_{v,k}\right|}(F_r+F_a\left(v_{v,k}\right)\left)\right),$

wherein tau is_whFor the net driving or braking torque at the wheels, r_dIs the dynamic radius of the wheel, B_whFor viscous drag, F_rAnd F_dFor the purpose of rolling resistance and air resistance,equivalent mass of the entire vehicle, J_rIs the moment of inertia of the rotating part in the vehicle.

Fig. 2 is a schematic diagram showing the relationship between the battery state of charge and the voltage according to the present invention, and the current battery state of charge can be obtained by measuring the external voltage.

Fig. 3 is a relationship between the battery charge state and the internal resistance of the battery according to the present invention under the charging or discharging condition, and the internal resistance of the battery can be obtained by looking up the current charge state.

And 5: the CAN bus transmits the engine output torque control quantity and the motor output torque control quantity obtained from the energy management main controller to the first singlechip and the second singlechip. The first single chip microcomputer and the second single chip microcomputer control the engine and the motor through the first A/D converter and the second A/D converter to complete the control process.

The data processing module and the objective function solving control output module are connected to a CAN bus through a CAN interface circuit, wherein the 32-bit singlechip series TC1767 is developed by a power system developed by Freescale.

By applying the invention to a practical vehicle for verification, the distribution torque of an engine and a motor is shown in fig. 4, fig. 4 is a schematic effect diagram of the embodiment of the invention, wherein the diagram (a) is a distribution diagram of the required torque, and the diagram (b) is a change diagram of the battery charge state, under the condition that the battery charge state is ensured to be changed within an allowable range, the invention ensures reasonable distribution of the required torque, and improves the fuel economy, as shown in the following table:

comparison of fuel saving ratio

	Original vehicle	Hybrid electric vehicle equipped with the controller	Oil saving rate
				Fuel economySex (L/100km)	42	29.2	30.5％

By the optimized control variable, the low oil consumption and the low emission potential of the hybrid electric vehicle are fully exerted, and the requirements of saving petroleum energy, protecting the atmospheric environment and reducing emission are met.

Claims (2)

1. A hybrid vehicle energy management control apparatus, characterized by comprising: the system comprises an energy management main controller, a CAN bus interface, a CAN bus, a first rotating speed torque sensor, a first single chip microcomputer, a first A/D converter, an engine, a second rotating speed torque sensor, a second single chip microcomputer, a second A/D converter, a motor, a vehicle speed acquisition sensor, a third A/D converter, a third single chip microcomputer, a speed change gear acquisition sensor, a battery voltage measurement circuit, a fourth single chip microcomputer and a fourth A/D converter; wherein,

the energy management main controller is formed by connecting a data processing module and an objective function solving control output module;

the CAN bus is respectively connected with a first single chip microcomputer, a second single chip microcomputer, a third single chip microcomputer, a fourth single chip microcomputer, a data processing module and an objective function solving control output module;

the first single chip microcomputer is respectively connected with the first rotating speed torque sensor and the first A/D converter;

the engine is respectively connected with a first rotating speed torque sensor and a first A/D converter;

the second singlechip is respectively connected with the second rotating speed torque sensor and the second A/D converter;

the motor is respectively connected with a second rotating speed torque sensor and a second A/D converter;

the third singlechip is respectively connected with the vehicle speed acquisition sensor, the third A/D converter and the speed change gear acquisition sensor;

the gearbox is respectively connected with a vehicle speed acquisition sensor, a third A/D converter and a speed change gear acquisition sensor;

the fourth singlechip is respectively connected with the battery voltage measuring circuit and the fourth A/D converter;

the battery is respectively connected with the battery voltage measuring circuit and the fourth A/D converter;

the control method of the control device comprises the following steps:

step 1: the first single chip microcomputer acquires the real-time rotating speed and the real-time torque of the engine through the first rotating speed torque sensor; the second single chip microcomputer acquires the real-time rotating speed and the real-time torque of the motor through a second rotating speed torque sensor;

the third singlechip acquires the gear of the real-time gearbox through a speed change gear acquisition sensor; the fourth singlechip obtains the voltage of the current battery through a battery voltage measuring circuit;

step 2: the first single chip microcomputer sends the acquired real-time rotating speed and real-time torque of the engine to the energy management main controller through the CAN bus; the second singlechip sends the acquired real-time rotating speed and real-time torque of the motor to the energy management main controller through a CAN bus; the third singlechip sends the collected real-time gearbox gear to the energy management main controller through a CAN bus; the fourth singlechip sends the obtained current battery voltage to the energy management main controller through a CAN bus;

and step 3: the data processing module of the energy management main controller processes the real-time rotating speed and the real-time torque of the engine received from the CAN bus to obtain the instantaneous fuel consumption of the engine; processing the battery voltage received from the CAN bus to obtain the current battery charge state; a data processing module of the energy management main controller receives gear information from a CAN bus;

and 4, step 4: the objective function solving control output module of the energy management main controller establishes a state variable of the battery charge state, the vehicle speed and the gear, a cost function of the battery charge state and the battery charge state, which are received from the data processing module, and solves the objective function by using the minimum value of the cost function as an objective function and the dynamic programming method to obtain the control quantity of the motor output torque so as to obtain the control quantity of the engine output torque; the energy management main controller does not output gear signals, the energy management main controller is only responsible for the output torques of the engine and the motor, and the gear decision is determined by the TCU;

and 5: the CAN bus transmits the engine output torque control quantity and the motor output torque control quantity obtained from the energy management main controller to the first single chip microcomputer and the second single chip microcomputer, and the first single chip microcomputer and the second single chip microcomputer control the engine and the motor through the first A/D converter and the second A/D converter to complete the control process.

2. The energy management control device of the hybrid electric vehicle as claimed in claim 1, wherein the first single chip microcomputer, the second single chip microcomputer, the third single chip microcomputer and the fourth single chip microcomputer are all single chip microcomputers TC 1767.