CN102092308B - Differential speed control method and device of intelligent multi-wheel independent power wheel - Google Patents

Abstract

An intelligent differential control method for multiple independent power wheels and its device are suitable for receiving the instruction of user to drive multiple power wheels. The control device includes a sensor, a motor driver, and a differential controller. The sensor is used for sensing a user command. The motor driver is used for driving the power wheel to rotate and outputting the operation parameters corresponding to the power wheel. The differential controller is provided with a differential rule and judges whether the power wheel operates in the intelligent mode according to the user instruction and the operation parameters. If the power wheel is operated in the intelligent mode, the differential speed controller executes a differential speed updating program. If the power wheel is not operated in the intelligent mode, the differential controller controls the motor driver to drive the power wheel according to the user instruction and the differential rule.

Description

Differential speed control method and device of intelligent multi-wheel independent power wheel

technical field

The invention relates to a differential speed control method and its device for a vehicle with multiple independent power wheels, in particular to a differential speed control method and its device which can intelligently and dynamically update the differential speed law.

Background technique

With the improvement of requirements for environmental protection, energy saving and quietness, electric vehicles are more valued by the industry than traditional gasoline and diesel vehicles. In order to improve transmission efficiency, more and more electric vehicles use in-wheel hub motors. In-wheel motors refer to the integration of motor power and tires into one, without the need for drive shafts, transmissions, differential gears or other transmission components. In this way, the energy loss caused by the transmission can be avoided.

Although the in-wheel motor (or power wheel) has the above-mentioned advantages, because the power and speed output of each power wheel are independent, the vehicle needs to be equipped with a central control system for intermediary deployment to meet the various driving states of the vehicle ( For example, the differential speed relationship when turning). The electronic differential system can perform speed matching for multi-wheel independent power drive vehicles. It is based on the size of the vehicle (including important parameters such as wheelbase and wheelbase) to develop an adaptive algorithm to obtain a differential relationship that satisfies kinematics. In addition, if the configuration setting of the driving wheels is changed (for example, front-drive setting, rear-drive setting), it will also cause applicability problems of the control algorithm. Therefore, compared with the "traditional mechanical differential mechanism", the "electronic differential controller" has the disadvantage of insufficient versatility and lack of practical convenience.

In order to be able to improve the electronic differential system with insufficient differential accuracy, many technologies have been developed in the industry. For example, the Chinese patent application No. 201021151, and the Taiwan patent publication No. I307319.

The former disclosed differential device uses the left (right) wheel comparison circuit module to compare the left (right) differential signal of the steering wheel with the pedal acceleration signal to determine the output of the left (right) wheel differential control signal. This method of simulating the differential speed relationship of the drive wheels by analog signals will have limited effect on vehicle stability control if there is no rigorous cross-simulation and comparison with vehicle dynamics.

The latter uses sensors to detect the current vehicle driving dynamics and driving control action requirements, and sends signals to the electronic control unit. The electronic control unit calculates and determines the rotation speed of each wheel of the vehicle to match the driving control action requirements. According to the speed control signal, the power drive unit controls the rotation dynamics of each wheel, so that the vehicle can drive according to the driving control action requirements, which can reduce cornering It can also effectively reduce the maximum roll angle generated by the vehicle during the cornering process, and can also effectively suppress the body roll angle during the process of entering the curve and ending the corner, thereby greatly reducing Possibility of the vehicle tipping over when cornering.

Although the industry has proposed the above-mentioned electronic differential system, in addition to the disadvantage of insufficient differential accuracy, it takes a long time to develop an adaptive algorithm according to the size of the vehicle. As short as half a month, as long as several years.

Contents of the invention

Based on the above-mentioned problems in the prior art, the present invention proposes an intelligent multi-wheel independent power wheel differential speed control method and a control device thereof. The differential speed control method and control device can dynamically and intelligently update the differential speed law according to the actual driving state of the vehicle, so as to quickly adjust the differential speed law suitable for the vehicle.

According to an embodiment, the differential speed control method of intelligent multi-wheel independent power wheels is suitable for receiving a user command to drive multiple power wheels to run. The control method includes: extracting user commands and driving parameters, the driving parameters are corresponding to The power wheel; judging whether the power wheel is running in the smart mode according to the user command and driving parameters; if so, executing the differential speed updating procedure; and if not, driving the power wheel to run according to the user command and the differential speed law.

According to an embodiment, the aforementioned step of judging whether the power wheels are operating in the smart mode according to the user command and driving parameters includes: judging whether the steering angle signal commanded by the user is greater than the steering angle threshold; if the steering angle signal is greater than the steering angle threshold, then according to The driving parameter determines whether the total torque is less than the torque threshold; and if the total torque is less than the torque threshold, it is determined that the power wheels are running in the smart mode.

According to an embodiment, the aforementioned step of judging whether the total torque is less than the torque threshold according to the driving parameters includes: obtaining the single-wheel torque according to the driving voltage, driving current and rotational speed of the driving parameters, and the single-wheel torque corresponds to the power wheel; summing up the single-wheel torque obtaining the total torque; and judging whether the total torque is less than a torque threshold.

According to an embodiment, the above-mentioned differential speed updating procedure includes: determining whether the rotational speed of the driving parameter is lower than a rotational speed threshold; and if so, updating the differential speed law according to the steering angle signal and the rotational speed commanded by the user.

According to an embodiment, the differential speed control device of the intelligent multi-wheel independent power wheel is adapted to receive a user's instruction to drive the power wheel to run. The control device includes: a sensor, a motor driver, and a differential speed controller. The sensor is used for sensing user commands. The motor driver is used to drive the power wheel to run and output the operation parameters corresponding to the power wheel. The differential speed controller has a differential speed law and judges whether the power wheels are running in the smart mode according to user commands and operating parameters. If the power wheels operate in the smart mode, the differential speed controller executes a differential speed updating procedure. If the power wheel is not running in the smart mode, the differential controller will control the motor driver to drive the power wheel according to the user command and the differential law

By means of the above differential control method and differential control device, when a vehicle with multiple independent power wheels is running, it can be judged whether the vehicle is in the smart mode (low-speed inertial cruise mode), and if so, the differential speed update procedure will be performed, and the inertial cruise mode will Next, the differential speed relationship between the wheels is dynamically updated in the differential speed law to obtain the most suitable differential speed law for the vehicle, which can be applied to vehicles with various types of independent power wheels, and effectively shorten the development of the differential speed law. Verification time.

Regarding the features and implementation of the present invention, the preferred embodiments are described in detail below in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic circuit block diagram of an embodiment of a differential speed control device according to the present invention.

FIG. 2 is a schematic flowchart of an embodiment of a differential speed control method according to the present invention.

FIG. 3 is a schematic flowchart of step S30 according to an embodiment of the differential speed control method of the present invention.

FIG. 4 is a schematic flowchart of step S34 according to an embodiment of the differential speed control method of the present invention.

FIG. 5 is a schematic flowchart of step S40 according to an embodiment of the differential speed control method of the present invention.

Description of reference symbols

10 Differential speed control device

12 Sensors

14 Differential speed controller

140 Differential Law

16 Motor drive

90 User Commands

92a, 92b, 92c, 92d Power wheels

94a, 94b, 94c, 94d In-wheel motors

Detailed ways

First, please refer to "Figure 1". FIG. 1 is a schematic circuit block diagram of an embodiment of a differential speed control device 10 according to the present invention. The differential speed control device 10 is adapted to receive a user command 90 to drive the power wheels 92a, 92b, 92c, 92d to run. Each powered wheel 92a, 92b, 92c, 92d has an in-wheel motor 94a, 94b, 94c, 94d, respectively. The in-wheel motors 94a, 94b, 94c, 94d drive the power wheels 92a, 92b, 92c, 92d to rotate when they run. It can be seen from the figure that the differential control device 10 can control the operation of four power wheels 92a, 92b, 92c, and 92d, but it is not limited thereto. The control device 10 can also control 2, 6 or 8 power wheels The wheels 92a, 92b, 92c, 92d are in motion. The power wheels 92a, 92b, 92c, 92d are electric power wheels in this embodiment.

The aforementioned user instruction 90 refers to the user's driving intention. The user command 90 may be, but not limited to, acceleration (or acceleration signal, acceleration intention, accelerator opening), deceleration (or brake signal, deceleration intention), and steering (or steering angle signal, steering intention).

It can be seen from the figure that the differential speed control device 10 includes a sensor 12 , a motor driver 16 , and a differential speed controller 14 . The sensor 12 is used for sensing the user command 90 and outputting a corresponding signal. The sensor 12 may include a steering angle sensor, an acceleration sensor, and a deceleration sensor. Wherein, the steering angle sensor is used for receiving the steering intention commanded by the user 90 and outputting a steering angle signal. The acceleration sensor is used for receiving the acceleration intention (or the opening degree of the accelerator pedal) commanded by the user 90 and outputting an acceleration signal. The deceleration sensor is used to receive the deceleration (brake pedal opening) intention of the user command 90 and output a deceleration signal.

The motor driver 16 is used to drive the power wheels 92a, 92b, 92c, 92d to run and output the operation parameters corresponding to the power wheels 92a, 92b, 92c, 92d. The operating parameters may be, but not limited to, the driving voltage V, the driving current I, and the rotation speed ω (or the rotation speed of the wheel). The rotational speed may be obtained from a Back Electro-magnetic Field (EMF) of the motor driver 16 . After the motors 94a, 94b, 94c, 94d are driven to run, the motor driver 16 will get back electromotive force. This back EMF can be detected and output in pulse mode. The physical quantity corresponding to the pulse may be the rotational speed (angular speed or rotational speed) of the motors 94a, 94b, 94c, 94d. Therefore, the motor driver 16 can output the driving current I, the driving voltage V and the rotational speed ω in real time while driving the power wheels 92a, 92b, 92c, 92d to run.

The above speed ω is measured through the counter electromotive force. In addition, some motors 94a, 94b, 94c, and 94d also have built-in Hall effect sensors. At this moment, the motor driver 16 can measure the rotational speed ω of the power wheels 92a, 92b, 92c, 92d through the Hall effect sensor. Although the rotation speed ω is referred to as the rotation speed per minute (rpm, rotation per minute) in this paper, it is not limited thereto.

The differential speed controller 14 has a differential speed law 140 and judges whether the power wheels 92a, 92b, 92c, 92d operate in the smart mode according to the user command 90 and the operating parameters V, I, ω. If the power wheels 92a, 92b, 92c, 92d operate in the smart mode, the differential speed controller 14 executes the differential speed updating procedure. If the power wheels 92a, 92b, 92c, 92d are not operating in the smart mode, the differential controller 14 controls the motor driver 16 to drive the power wheels 92a, 92b, 92c, 92d according to the user command 90 and the differential law 140 . The aforementioned so-called power wheels 92a, 92b, 92c, 92d operating in the intelligent mode means that the differential speed controller 14 judges that the current operation mode of the power wheels 92a, 92b, 92c, 92d belongs to the state (opportunity) for differential speed learning. In the smart mode, each power wheel 92a, 92b, 92c, 92d is in a free-rolling state, that is, it does not receive or only receives very low driving power. At this time, the relationship between the rotational speeds ω of the power wheels 92a, 92b, 92c, and 92d is a natural phenomenon adapted to the current steering angle, so it can be recorded in the differential speed law (or database) respectively (detailed later) ).

The aforementioned differential speed law 140 can be a differential speed law 140 derived and verified based on the steering angle, wheelbase, wheelbase, driving mode (front-wheel drive, rear-wheel drive, or four-wheel drive), etc., or it can be verified A lookup table for . The look-up table is usually but not limited to look up the speed difference relationship or speed difference value among the driven power wheels 92a, 92b, 92c, 92d by steering angle. The differential speed law 140 can be built in the differential speed controller 14 , or a memory can be arranged beside the differential speed controller 14 , and the differential speed law 140 can be stored in the memory and accessed by the differential speed controller 14 .

For how the differential controller 14 judges whether the power wheels 92a, 92b, 92c, 92d are running in the smart mode, and how to perform the differential update procedure in the smart mode, please refer to "FIG. 2". It is a schematic flowchart of an embodiment of the differential speed control method according to the present invention.

It can be seen from the figure that the differential speed control method of the intelligent multi-wheel independent power wheels 92a, 92b, 92c, 92d is suitable for receiving user instructions 90 to drive the power wheels 92a, 92b, 92c, 92d to run. The differential speed control method includes the following steps:

Step S20: Retrieve the user command 90 and the driving parameters V, I, ω, the driving parameters are corresponding to the power wheels 92a, 92b, 92c, 92d;

Step S30: judging whether the power wheels 92a, 92b, 92c, 92d are operating in the smart mode according to the user command 90 and the driving parameters V, I, ω;

Step S40: If yes, execute the differential speed update procedure; and

Step S50: If not, drive the power wheels 92a, 92b, 92c, 92d to run according to the user command 90 and the differential speed law 140 .

As mentioned above, the user command in step S20 may include the steering angle, the opening of the accelerator pedal, and the opening of the brake pedal. The driving parameters in step S20 include the driving voltage V, the driving current I and the rotational speed ω. The correspondence between driving parameters V, I, ω and power wheels 92a, 92b, 92c, 92d is that each power wheel 92a, 92b, 92c, 92d has a group of driving voltage V, driving current I and rotating speed ω. In this way, the differential speed controller 14 can obtain information such as the speed of the vehicle, the driving torque of each power wheel 92a, 92b, 92c, 92d, and the like. For example, the vehicle speed can be obtained from the average rotation speed ω of all the powered wheels 92a, 92b, 92c, 92d, and the torque of each powered wheel 92a, 92b, 92c, 92d can be calculated by the following formula (1).

$T_{\mathrm{no}}=\frac{I_{\mathrm{no}}{V}_{\mathrm{no}}}{{\mathrm{\ω}}_{\mathrm{no}}}$ .........................................Formula 1)

Among them, n is the nth power wheel, T _n is the torque of the nth power wheel, V _n is the driving voltage of the nth power wheel, I _n is the driving current of the nth power wheel, ω _n is the nth power wheel The rotational speed of a power wheel.

In addition, if it is desired to calculate the total torque, it can be calculated by the following formula (2):

$T_{\mathrm{all}}={\mathrm{\Σ}}_{i=1}^{\mathrm{no}}\frac{i_i\&Center\; Dot;V_i}{{\mathrm{\ω}}_i}$ ..................................... (2)

Wherein, the T _all is the total torque, n is the number of power wheels, I _i is the driving current corresponding to the i-th power wheel, V _i is the driving voltage corresponding to the i-th power wheel, and ω _i is The rotational speed corresponding to the i-th power wheel.

For step S30: "judging whether the power wheels 92a, 92b, 92c, 92d are operating in the smart mode according to the user command 90 and the driving parameters V, I, ω", please refer to "FIG. 3". The smart mode here refers to the fact that the current driving state of the vehicle is a non-driving state (no acceleration or deceleration), and the vehicle adopts a non-driving cruising method based on the current speed, its inertia and the interaction between the various components of the vehicle. mode. That is to say, the wheel is currently in a state of free rolling according to its inertia (it can be said that the vehicle is in a sliding state). If the vehicle is traveling in an undriven cruising mode, the speed relationship between the wheels at this time is the best differential speed relationship of the vehicle. At this time, the current relationship between the steering angle and the speed can be recorded as its Then the differential law 140 when the vehicle is being driven at this steering angle.

As can be seen from "Fig. 3", step S30 includes:

Step S32: judging whether the steering angle signal of the user command 90 is greater than the steering angle threshold;

Step S34: If the steering angle signal is greater than the steering angle threshold, judge whether the total torque is less than the torque threshold according to the driving parameters; and

Step S36: If the total torque is less than the torque threshold, it is determined that the power wheels 92a, 92b, 92c, 92d are running in the smart mode.

Step S38: If the steering angle signal is not greater than the steering angle threshold, it is determined that the power wheels 92a, 92b, 92c, 92d are not operating in the smart mode.

The steering angle signal of the user command 90 in step S32 is output by the sensor 12 . The steering angle threshold is used to judge whether the steering angle signal belongs to the steering state. If the steering angle signal is greater than the steering angle threshold, it means that the current user command 90 includes a signal to turn. At this time, the differential speed controller 14 needs to refer to the differential speed law 140 to drive the power wheels 92a, 92b, 92c, 92d. The determination of the steering angle signal depends on the minimum angle of the differential law 140 (such as the critical angle of the steering angle), which can generally be set to 0.1 degree or other values. If the steering angle signal is not greater than the steering angle threshold, it is determined that the power wheels 92a, 92b, 92c, 92d are not operating in the smart mode (step S38).

Next, step S34 is to determine whether the total torque is less than the torque threshold according to the driving parameters when the steering angle signal is greater than the steering angle threshold. The total torque is obtained from the real-time formula (2) above. The determination of the total torque is used to determine whether the vehicle is currently not being driven by the motor driver 16 . In order to determine whether the vehicle is not being driven by the motor driver 16 , in addition to knowing from the total torque, it is also possible, but not limited to, the driving current or the driving power. That is to say, if the driving current is close to zero (or the current threshold), it means that the vehicle is not driven by the motor driver 16 at present. Or use a method of judging whether the driving power is less than the power threshold. This torque threshold can be set to zero or a positive value close to zero. For example the torque threshold may be 50 N-m (Newton meters). The current threshold may be 10 amps. The power threshold may be 500 watts. Considerations for setting the torque threshold may be no acceleration command, the level of system noise, and so on.

If the total torque is not greater than the torque threshold, it is determined that the power wheels 92a, 92b, 92c, 92d are not operating in the smart mode (step S38)

For the procedure of step S34, please refer to "FIG. 4" for reading. As can be seen from the figure, step S34 includes:

Step S340: Obtain the single-wheel torque according to the driving voltage, driving current and rotational speed of the driving parameters, and the single-wheel torque corresponds to the power wheels 92a, 92b, 92c, 92d;

Step S342: adding up the single wheel torque to obtain the total torque; and

Step S344: Determine whether the total torque is less than a torque threshold.

Steps S340 and S342 are the expansion process of the above formula (2).

From step S32 and step S34, it can be known that, when the steering angle and total torque meet the conditions of steps S32 and S34 respectively, the vehicle is in the undriven cruising mode, that is, the aforementioned smart mode (step S36 ). If the vehicle (power wheel) is in the smart mode, the "execute differential speed update program" in step S40 can be executed.

Please refer to “ FIG. 5 ”, which is a schematic flowchart of step S40 according to an embodiment of the differential speed control method of the present invention. As can be seen from the figure, the "differential speed update program" of step S40 includes:

Step S402: judging whether the rotational speed of the driving parameter is lower than the rotational speed threshold;

Step S404: If yes, update the differential speed law 140 according to the steering angle signal and the rotational speed of the user command 90; and

Step S406: If not, end the differential speed update procedure.

Step S402 judges whether the rotational speed of each power wheel 92a, 92b, 92c, 92d is too high. If the rotational speed is too high, there may be a skid phenomenon among the power wheels 92a, 92b, 92c, and 92d. That is to say, if each power wheel 92a, 92b, 92c, 92d (vehicle) is currently traveling under the cruising state not driven, but if its rotating speed is too high, a certain power wheel 92a, 92b, 92c, 92d will likely Slip will occur. As a result, the differential speed relationship between the power wheels 92a, 92b, 92c, and 92d is not a purely natural (or non-artificial) differential speed relationship, but a "differential speed relationship with slip", which is not suitable for recording . In other words, the differential speed update program in step S40 is to update the purely natural (non-artificial) differential speed relationship between the power wheels 92a, 92b, 92c, 92d into the differential speed law 140, and the above-mentioned differential speed in step S402 is not satisfied. The situation would not be suitable to be recorded. The foregoing rotational speed threshold (or may be called the wheel rotational speed threshold) may be 1000 revolutions per minute (rpm, rotation per minute). Secondly, step S402 can also be added to determine whether the rotational speed of each power wheel 92a, 92b, 92c, 92d is too small, and if the rotational speed is too small, it is not suitable to record the differential speed relationship among the wheels.

The rotational speed threshold in step S402 can be obtained through experiments. Generally speaking, at a lower vehicle speed, the power wheels 92a, 92b, 92c, 92d will not have slippage. Thus, the speed threshold can be 10, 20, 30 or 40 kilometers per hour (Km/hr). However, this rotational speed threshold can also vary with the steering angle. For example, if the steering angle is larger, the speed threshold can be set smaller. Conversely, if the steering angle is larger, the speed threshold can be set slightly larger. The reason for this setting method is that when the steering angle is larger, the chances of the wheels slipping increase, so it is necessary to obtain a non-artificial differential relationship more confidently at a lower speed.

When the situation in step S402 is satisfied, the steering angle signal and the rotational speed of the user command 90 are updated in the differential speed law 140 according to step S404 . That is to say, the relationship between the steering angle and the rotational speeds of the power wheels 92a, 92b, 92c, and 92d corresponding to the steering angle is updated to the differential speed law 140 . If the differential speed law 140 is a relational expression, the calculation of the relational expression (such as regression, approach line, etc.) can be performed again. If the differential speed law 140 is a look-up table (Look-up Table), then the differential speed value of each power wheel 92a, 92b, 92c, 92d corresponding to the steering angle can be directly updated.

If step S402 is not met, follow step S406 "end the differential speed update procedure". Go back to step S20.

For the above smart mode, whether the obtained rotational speed relationship and steering angle are suitable for being updated in the differential speed law 140, another judging rule can be added: step S408 "judging whether the deceleration signal of the user command 90 is lower than the deceleration threshold value" . This step can exclude the state that the user is stepping on the brake. Since the user steps on the brakes, the wheels may slip. At this time, the differential speed relationship of each wheel may not be suitable for recording, and may not be used as a basis for updating the differential speed law 140 . The aforementioned deceleration threshold may be but not limited to a certain percentage of the pedaling stroke of the brake pedal, such as 10% of the full pedaling stroke. Of course, the present invention is not limited thereto, and in some occasions, the state of stepping on the brake can also be included as a reference for updating the differential speed law 140 .

Furthermore, in order to increase the better way of updating the differential speed law 140, a judgment process can be added. That is to say, before step S404, add a step S403 "judging whether the rotation speed falls within a reasonable range according to the steering angle", and if so, execute step S404 "update the differential speed law 140 according to the steering angle signal and the rotation speed of the user command 90". If not, execute step S406 "end the differential speed updating procedure".

The reasonable range in this step S403 refers to the reasonable differential speed relationship among the power wheels 92a, 92b, 92c, 92d. The reasonable differential speed relationship may be a reasonable speed difference derived from the general differential speed theory based on parameters such as wheelbase and wheelbase. Therefore, if the differential speed relationship of each wheel obtained by the differential speed controller 14 does not fall within the reasonable speed difference, it means that there is a problem and will not be updated to avoid unpredictable results.

In addition, regarding the timing of step S404 "updating the differential speed law 140", the following factors may also be considered:

1. If the current steering angle commanded by the user 90 is the same as the steering angle to be updated, in order to avoid frustration, the current steering angle can be judged before the differential speed law 140 is updated. When the steering angle is , the differential speed law 140 is updated.

2. In order to reduce the update frequency, a memory can be configured inside or outside the differential speed controller 14 to store a backup law (the backup of the existing differential speed law 140). Every time the differential speed law 140 is updated, the backup law is also updated. When there is a new updateable steering angle and its corresponding differential speed relationship, first confirm whether the current differential speed relationship to be updated is the same as the backup law, and if not, wait for an opportunity to update the differential speed law in use 140 .

3. In order to reduce the update frequency, it is also possible to first confirm whether the same data has been updated in the differential speed law for the data to be updated. If so, the update will not be performed to avoid repeated update of the same data.

Regarding step S50 "driving the power wheels 92a, 92b, 92c, 92d to run according to the user command 90 and the differential speed law 140" refers to obtaining the steering angle signal of each wheel on the differential speed law 140 according to the steering angle signal in the user command 90 The differential speed relationship is then used to drive each power wheel 92a, 92b, 92c, 92d. For example, if the current steering angle is 5 degrees, then look up the differential speed relationship between the power wheels 92a, 92b, 92c, and 92d corresponding to the steering angle of 5 degrees on the differential speed law 140 (if it is a look-up table), and refer to The acceleration signal or deceleration signal forms the driving signals of each wheel, and then the differential controller 14 provides the driving signals to the motor driver 16 to drive the power wheels 92a, 92b, 92c, 92d to rotate.

By means of the above-mentioned differential control method and device of the intelligent multi-wheel independent power wheels 92a, 92b, 92c, 92d, the designer can be ahead of time when designing a vehicle with multi-wheel independent power wheels 92a, 92b, 92c, 92d. A more general and extensive differential speed law 140 is built in the differential speed controller 14, and then the tester continues to drive the vehicle at various steering angles in an intelligent mode (which can be called a learning mode or a non-artificial differential speed relationship) Mode), at this time, the differential speed control method and device will automatically and dynamically update the differential speed law 140, and then obtain a differential speed law 140 that fully conforms to the vehicle. In this way, the design and verification time can be quickly shortened, and a more accurate differential speed relationship can be obtained. Simultaneously, the differential speed law 140 completed by the present invention is a customized differential speed law 140 completed under various conditions of the vehicle. The customized differential speed law 140 will be more accurate than the differential speed law configured for the same vehicle in the prior art. Secondly, after the vehicle leaves the factory, the differential update program can also be selectively turned on or off to meet different needs.

Claims (25)

1. the differential speed control method of intelligent many wheel independent power wheels is suitable for receiving a plurality of power wheel runnings of user's order-driven, and this differential speed control method comprises:

Capture this user's instruction and a plurality of driving parameter, this drives parameter to should power wheel;

Judge according to this user's instruction and this driving parameter whether this power wheel runs on an intelligent mode, wherein this intelligent mode is that the present motoring condition of vehicle belongs to non-driven state and vehicle adopts the pattern of advancing without the mode of cruising that drives according to the current speed of a motor vehicle according to the interactive relationship between its inertia and each spare part of vehicle;

If then carry out a differential refresh routine; And

If not, then drive this power wheel running according to this user's instruction and a differential rule.

2. differential speed control method as claimed in claim 1, wherein should judge that the step whether this power wheel runs on this intelligent mode comprised according to this user's instruction and this driving parameter:

Judge that whether a deflection angle signal of this user's instruction is greater than a deflection angle threshold value;

If this deflection angle signal greater than this deflection angle threshold value, then drives parameter according to this and judges that whether a sum total moment of torsion is less than a torque threshold; And

If should sum up moment of torsion less than this torque threshold, determine then that this power wheel was to run on this intelligent mode.

3. differential speed control method as claimed in claim 2, wherein judge that according to this user's instruction and this driving parameter the step whether this power wheel runs on this intelligent mode also comprises: if this deflection angle signal, then determines non-this intelligent mode that runs on of this power wheel not greater than this deflection angle threshold value.

4. differential speed control method as claimed in claim 2, wherein judge that according to this user's instruction and this driving parameter the step whether this power wheel runs on this intelligent mode also comprises: if this sum total moment of torsion, then determines non-this intelligent mode that runs on of this power wheel not less than this torque threshold.

5. differential speed control method as claimed in claim 2, wherein judge that according to this driving parameter whether this sum total moment of torsion comprises less than the step of this torque threshold:

Obtain a plurality of single-wheel moments of torsion according to a plurality of driving voltages of this driving parameter, a plurality of drive current and a plurality of rotating speed, this single-wheel moment of torsion is corresponding to this power wheel;

Add up this single-wheel moment of torsion and obtain this sum total moment of torsion; And

Judge that whether this sum total moment of torsion is less than this torque threshold.

6. differential speed control method as claimed in claim 2, wherein this torque threshold is 50 newton meteies.

7. differential speed control method as claimed in claim 2, wherein this deflection angle threshold value is 0.1 degree.

8. differential speed control method as claimed in claim 1, wherein this differential refresh routine comprises:

Whether a plurality of rotating speeds of judging this driving parameter are lower than a rotary speed threshold value;

If then according to a deflection angle signal and this rotating speed of this user's instruction, upgrade this differential rule; And

If not, then finish this differential refresh routine.

9. differential speed control method as claimed in claim 8, wherein this rotary speed threshold value is 100 to turn/per minute.

10. differential speed control method as claimed in claim 8, wherein judge to comprise before whether a plurality of rotating speeds of this driving parameter are lower than the step of this rotary speed threshold value at this:

Whether a deceleration signal of judging this user's instruction is lower than a deceleration threshold value;

If then carry out this and judge whether this rotating speed of this driving parameter is lower than the step of this rotary speed threshold value; And

If not, then finish this differential refresh routine.

11. differential speed control method as claimed in claim 10 should the deceleration threshold value be the ten Percent of a pedal stroke wherein.

12. differential speed control method as claimed in claim 8 wherein comprises in this step of upgrading this differential rule:

Judge according to this deflection angle whether this rotating speed falls within a zone of reasonableness;

If then this deflection angle and this rotating speed are updated to this differential rule; And

If not, then finish the step of this differential refresh routine.

13. differential speed control method as claimed in claim 1, wherein this user's instruction comprises aperture, and the aperture of a brake pedal of a wheel turning angle, a Das Gaspedal.

14. differential speed control method as claimed in claim 1 wherein should judge that the step whether this power wheel runs on this intelligent mode comprised according to this user's instruction and this driving parameter:

Judge that whether a deflection angle signal of this user's instruction is greater than a deflection angle threshold value;

If this deflection angle signal greater than this deflection angle threshold value, then judges that according to this driving parameter whether a drive current is less than a current threshold; And

If it is to run on this intelligent mode that this drive current, then determines this power wheel less than this current threshold.

15. differential speed control method as claimed in claim 14, wherein this current threshold is 10 amperes.

16. differential speed control method as claimed in claim 1 wherein should judge that the step whether this power wheel runs on this intelligent mode comprised according to this user's instruction and this driving parameter:

Judge that whether a deflection angle signal of this user's instruction is greater than a deflection angle threshold value;

If this deflection angle signal greater than this deflection angle threshold value, then judges that according to this driving parameter whether a driving power is less than a power threshold; And

If it is to run on this intelligent mode that this driving power, then determines this power wheel less than this power threshold.

17. differential speed control method as claimed in claim 16, wherein this power threshold is 500 watts.

18. the device for controlling differential speed of intelligent many wheel independent power wheels is suitable for receiving a plurality of power wheel runnings of user's order-driven, this device for controlling differential speed comprises:

A plurality of sensors are in order to this user's instruction of sensing;

One motor driver is in order to drive the running of this power wheel and output to a plurality of operating parameters that should power wheel; And

One differential controller, has a differential rule, this differential controller is to judge according to this user's instruction and this operating parameters whether this power wheel runs on an intelligent mode, if this power wheel runs on this intelligent mode, this differential controller is then carried out a differential refresh routine, if non-this intelligent mode that runs on of this power wheel, this differential controller is then controlled this motor driver to drive this power wheel according to this user's instruction and this differential rule

Wherein this intelligent mode is that the present motoring condition of vehicle belongs to non-driven state and vehicle adopts the pattern of advancing without the mode of cruising that drives according to the current speed of a motor vehicle according to the interactive relationship between its inertia and each spare part of vehicle.

19. device for controlling differential speed as claimed in claim 18, wherein this sensor comprises a deflection angle sensor, this deflection angle sensor is in order to receive this user's instruction and to export a deflection angle signal, this differential controller obtains a sum total moment of torsion according to this operating parameters, this differential controller is during less than a torque threshold, to judge that this power wheel runs on this intelligent mode greater than a deflection angle threshold value and this sum total moment of torsion in this deflection angle signal.

20. device for controlling differential speed as claimed in claim 19, wherein this operating parameters comprises a plurality of driving voltages, a plurality of drive current, reaches a plurality of rotating speeds, and this sum total moment of torsion meets following relational expression:

$T_{\mathrm{all}}={\∑}_{i=1}^n\frac{I_i\·V_i}{{\mathrm{\ω}}_i}$

Wherein, this T _AllBe this sum total moment of torsion, n is the number of this power wheel, I _iBe i this drive current that power wheel is corresponding, V _iBe i this driving voltage that power wheel is corresponding, ω _iBe this rotating speed corresponding to this i power wheel.

21. device for controlling differential speed as claimed in claim 18, wherein this sensor comprises:

One deflection angle sensor is in order to receive this user's instruction and to export a deflection angle signal;

One accelerates sensor, in order to receive this user's instruction and to export one and accelerate signal; And

One deceleration sensor is in order to receive this user's instruction and to export a deceleration signal.

22. device for controlling differential speed as claimed in claim 21, wherein this differential controller is when running on this intelligent mode in this power wheel is non-, to control this motor driver to drive this power wheel according to this deflection angle signal, this acceleration signal, this deceleration signal and this differential rule.

23. device for controlling differential speed as claimed in claim 18, wherein this differential refresh routine comprises:

Whether a plurality of rotating speeds of judging this driving parameter are lower than a rotary speed threshold value; And

If then according to a deflection angle signal and this rotating speed of this user's instruction, upgrade this differential rule.

24. device for controlling differential speed as claimed in claim 23 wherein judges to comprise before whether a plurality of rotating speeds of this driving parameter are lower than the step of this rotary speed threshold value at this:

Whether a deceleration signal of judging this user's instruction is lower than a deceleration threshold value; And

If not, then finish this differential refresh routine.

25. device for controlling differential speed as claimed in claim 23, wherein the step of this differential rule of this renewal comprises:

Judge according to this deflection angle signal whether this rotating speed falls within a zone of reasonableness; And

If then this deflection angle signal and this rotating speed are updated to this differential rule.

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