Method and device for determining hill-hold torque, motor controller and vehicle

Abstract

The present disclosure relates to a method and device for determining hill-hold torque, a motor controller and a vehicle, and relates to the technical field of vehicles. The method comprises: inputting the vehicle moment of inertia, the motor speed of the motor and the target braking torque output by the vehicle controller into a torque observer to obtain a predicted load torque; in the case that a first error between the predicted load torque and an actual load torque satisfies a first preset condition, taking the predicted load torque when the first error satisfies the first preset condition as a target load torque; and determining the hill-hold torque according to the target load torque and a torque output by a speed loop of the vehicle. The hill-hold torque method provided by the present disclosure can quickly obtain the hill-hold torque, and avoid the vehicle from sliding or rushing forward on a hill.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of vehicles, in particular to a hill-hold torque determination method and device, a motor controller and a vehicle. BACKGROUND

[0002] At present, a hill-hold torque needs to be output when a vehicle is hill-holding, so as to make the vehicle stop on a slope according to the hill-hold torque.

[0003] In the related art, due to the existence of vehicle models, loads and slopes, the PI parameters of the speed loop of the vehicle need to be debugged multiple times, so that the vehicle can output a hill-hold torque with good hill-hold effect. However, this method of repeatedly debugging the PI parameters of the speed loop undoubtedly increases the debugging workload. SUMMARY

[0004] To overcome the problems in the related art, the present disclosure provides a hill-hold torque determination method and device, a motor controller and a vehicle.

[0005] According to a first aspect of an embodiment of the present disclosure, a hill-hold torque determination method is provided, applied to a vehicle, the vehicle comprising a motor and a vehicle controller, and the method comprising:

[0006] inputting the vehicle moment of inertia, the motor speed and the target braking torque output by the vehicle controller into a torque observer to obtain a predicted load torque;

[0007] in a case where a first error between the predicted load torque and an actual load torque satisfies a first preset condition, taking the predicted load torque when the first error satisfies the first preset condition as a target load torque;

[0008] determining a hill-hold torque according to the target load torque and a torque output by a speed loop of the vehicle.

[0009] Optionally, the method further comprises:

[0010] in a case where the first error does not satisfy the first preset condition, updating the motor speed and the target braking torque until the first error satisfies the first preset condition.

[0011] Optionally, the updating of the motor speed and the target braking torque in the case where the first error does not satisfy the first preset condition until the first error satisfies the first preset condition comprises:

[0012] In a case that the first error does not satisfy a first preset condition, and / or a second error between the first predicted motor speed and a first actual motor speed does not satisfy the first preset condition, the motor speed is updated to the first predicted motor speed, and the target brake torque is updated to the target brake torque input to the torque observer this time, until the first error and the second error satisfy the first preset condition; wherein the first predicted motor speed is a motor speed predicted by the torque observer.

[0013] Optionally, before the vehicle inertia, the motor speed and the target brake torque output by the vehicle controller are input to the torque observer to obtain the predicted load torque, the method further comprises:

[0014] According to the target brake torque and the motor speed, the vehicle inertia is determined.

[0015] Optionally, the determination of the vehicle inertia according to the target brake torque and the motor speed comprises:

[0016] The target brake torque and an initial inertia are input to an inertia model to predict a second predicted motor speed;

[0017] In a case that a third error between the second actual motor speed and the second predicted motor speed does not satisfy a second preset condition, the initial inertia is updated until the third error satisfies the second preset condition;

[0018] According to the third error when the second preset condition is satisfied, the vehicle inertia is obtained.

[0019] Optionally, the obtaining of the vehicle inertia according to the third error when the second preset condition is satisfied comprises:

[0020] According to the third error when the second preset condition is satisfied, a first system coefficient of the inertia model in the last calculation and prediction, and the target brake torque input to the inertia model this time, a second system parameter of the inertia model in this calculation and prediction is obtained;

[0021] According to the second system parameter, the vehicle inertia is obtained.

[0022] Optionally, the inertia model is constructed by the following steps:

[0023] The first motor speed, the second motor speed and the third motor speed are taken as the output of the inertia model, and the first target brake torque and the second target brake torque are taken as the input of the inertia model, so as to construct the inertia model;

[0024] The first motor speed is a motor speed of the motor at a first time, the second motor speed is a motor speed of the motor at a second time, and the third motor speed is a motor speed of the motor at a third time. The second time, the first time, and the third time are arranged in time sequence. The first target brake torque is a target brake torque output by the vehicle controller at the first time, and the second target brake torque is a target brake torque output by the vehicle controller at the second time.

[0025] Optionally, the determining the hill-hold torque according to the target load torque and the torque output by the speed loop of the vehicle comprises:

[0026] The sum of the target load torque and the torque output by the speed loop of the vehicle is taken as the hill-hold torque.

[0027] According to a second aspect of the embodiment of the present disclosure, a hill-hold torque determination device is provided, comprising:

[0028] The prediction module is configured to input the vehicle inertia, the motor speed, and the target brake torque output by the vehicle controller into a torque observer to obtain a predicted load torque.

[0029] The target load torque determination module is configured to, in a case where a first error between the predicted load torque and an actual load torque satisfies a first preset condition, take the predicted load torque when the first error satisfies the first preset condition as a target load torque.

[0030] The hill-hold torque determination module is configured to determine a hill-hold torque according to the target load torque and a torque output by a speed loop of the vehicle.

[0031] According to a third aspect of the embodiment of the present disclosure, a motor controller is provided, and the motor controller implements the steps of the hill-hold torque determination method provided by the first aspect of the embodiment of the present disclosure when executed.

[0032] According to a fourth aspect of the embodiment of the present disclosure, a vehicle is provided, and the vehicle is configured with the motor controller provided by the fourth aspect of the embodiment of the present disclosure.

[0033] The technical solution provided by the embodiment of the present disclosure can include the following beneficial effects:

[0034] The present disclosure proposes to use a torque observer to predict a predicted load torque close to an actual load torque, so that, since the predicted load torque directly given by the present disclosure is close to the actual load torque actually required by the motor driving the vehicle load, the hill hold torque obtained by combining the predicted load torque with the torque output by the speed loop can directly realize the hill hold of the vehicle. In the first aspect, the predicted predicted load torque is directly used as the feedforward term of the speed loop, so that it is not necessary to repeatedly debug the PI parameters of the speed loop, thereby avoiding the debugging workload caused by repeatedly debugging the PI parameters of the speed loop; in the second aspect, since it is not necessary to repeatedly debug the PI parameters of the speed loop, the time for debugging the PI parameters of the speed loop is saved, so that the hill hold torque can be obtained more quickly, and the hill hold time is shortened; in the third aspect, after the hill hold time is shortened, the distance of hill hold front collision or rear sliding can be avoided.

[0035] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0036] The accompanying drawings, which are incorporated into the specification and constitute part of the specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure.

[0037] Figure 1 is a flowchart of a hill hold torque determination method according to an exemplary embodiment;

[0038] Figure 2 is a schematic diagram of a torque observer according to an exemplary embodiment;

[0039] Figure 3 is a schematic diagram of a current loop and a speed loop according to an exemplary embodiment;

[0040] Figure 4 is a logic diagram of hill hold according to an exemplary embodiment;

[0041] Figure 5 is a flowchart of setting current loop PI parameters and speed loop PI parameters according to an exemplary embodiment;

[0042] Figure 6 is a flowchart of identifying the moment of inertia of the vehicle according to an exemplary embodiment;

[0043] Figure 7 is a block diagram of a hill hold torque determination device according to an exemplary embodiment;

[0044] Figure 8 is a block diagram of a hill hold torque determination device according to an exemplary embodiment. DETAILED DESCRIPTION

[0045] The exemplary embodiments will be described in detail herein with reference to the attached drawings. In the following description, like reference numerals refer to like elements, unless the context clearly dictates otherwise. The following description of exemplary embodiments is not representative of all possible embodiments consistent with the present disclosure. Instead, it is merely intended to provide an example of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0046] It is noted that all the actions of acquiring signals, information or data in the present disclosure are carried out in compliance with the corresponding data protection regulations policy of the country where the device is located, and with the authorization given by the corresponding device owner.

[0047] Figure 1 A hill hold torque determination method is shown according to an exemplary embodiment, which is applied to a vehicle including a motor and a vehicle control unit, and the method includes the following steps:

[0048] In step S101, the vehicle moment of inertia, the motor speed and the target brake torque output by the vehicle control unit are input into the torque observer to obtain the predicted load torque.

[0049] In some embodiments, the moment of inertia can reflect the inertia of the vehicle in the rotating state, and the angular velocity of the vehicle with large moment of inertia is more difficult to change. Under the action of the same external torque, the angular velocity obtained by the vehicle with large moment of inertia is small, which indicates that the motion state of the vehicle is more difficult to change. The vehicle moment of inertia includes the moment of inertia of the motor and the moment of inertia of the vehicle load.

[0050] In some embodiments, the motor speed of the motor is the angular velocity of the motor rotation.

[0051] In some embodiments, the vehicle control unit (VCU) obtains an initial brake torque according to the brake pedal opening degree and the motor speed; corrects the initial brake torque according to the maximum charging current allowed by the battery to obtain a target brake torque; and sends a parking instruction to the motor control, wherein the target brake torque is carried in the parking instruction.

[0052] In some embodiments, the predicted load torque is the torque required by the torque observer to drive the vehicle load.

[0053] In some embodiments, the torque observer is a reconstructed operating system according to the actual motion system of the vehicle, please refer to Figure 2As shown, after inputting the motor speed and target braking torque Wr into the torque observer, the first predicted motor speed Wr_Pre and predicted load torque Tl_Pre are obtained. The motion system refers to the equation of motion constructed based on the motion of the vehicle's motor. The motor motion includes parameters such as motor speed and braking torque generated over time during vehicle travel.

[0054] Alternatively, the actual equation of motion is formulated as follows:

[0055]

[0056] Among them, ω r is the motor speed; T e is the target braking torque; T l is the load torque; B is the damping coefficient; J is the moment of inertia of the vehicle.

[0057] Optionally, in order to facilitate the subsequent construction of the observation equation of the torque observer, the formula (1) can be Simplified to A; Simplify to x; Simplify to B; T e Simplified to u, we get the following formula (2):

[0058]

[0059] Among them, y is the output, is the motor speed; C is a constant. When C is 1, the predicted output motor speed is equal to the input motor speed; when C is 2, the predicted output motor speed is equal to twice the input motor speed.

[0060] From the actual motion equation shown in formula (2), it can be seen that the motor speed, target braking torque, damping coefficient and vehicle moment of inertia are input as known quantities into After that, the actual load torque can be obtained; after the motor speed is input into y=Cx, the first actual motor speed can be obtained.

[0061] Since formula (2) is a true motion equation constructed in combination with the actual motion of the vehicle motor, the actual load torque and the actual motor speed output by formula (2) are accurate.

[0062] Based on the motion equation of the motor shown in formula (2), the present disclosure constructs the following observation equation of the torque observer:

[0063]

[0064] Among them, A is J is the moment of inertia of the vehicle; is the observation equation ω r is the motor speed; T l is the predicted load torque; B is u is the target braking torque T e ; K is the feedback matrix, K = [k1k2] T ; y is the actual motor speed output by the motion equation; is the motor speed predicted by the observation equation.

[0065] As can be seen from the constructed observation equation shown in formula (3) above, the motor speed, the target braking torque and the vehicle moment of inertia are input as known quantities into , and the predicted load torque, which is an unknown quantity, can be calculated; the motor speed is input into , and the first predicted motor speed can be calculated.

[0066] Figure 2 is a torque observer constructed according to the observation equation, from Figure 2 it can be seen that after the motor speed ω r and the target braking torque T e are input into the torque observer, the torque observer will predict the first predicted motor speed ω r_pre and the predicted load torque T l . pre .

[0067] In step S102, in a case where a first error between the predicted load torque and the actual load torque satisfies a first preset condition, a predicted load torque when the first error satisfies the first preset condition is taken as a target load torque.

[0068] In some embodiments, in a case where the first error between the predicted load torque and the actual load torque does not satisfy the first preset condition, the motor speed and the target braking torque are updated until the first error satisfies the first preset condition.

[0069] In some embodiments, for each iteration in the multiple iteration calculation process, the motor speed and the target braking torque are updated to predict the predicted load torque; in a case where the first error between the predicted load torque and the actual load torque does not satisfy the first preset condition, the motor speed and the target braking torque are updated again to obtain the predicted load torque again. The steps of “updating the motor speed and the target braking torque to predict the predicted load torque; in a case where the first error between the predicted load torque and the actual load torque does not satisfy the first preset condition, updating the motor speed and the target braking torque to obtain the predicted load torque again” are repeatedly performed until the first error between the predicted load torque and the actual load torque satisfies the preset condition.

[0070] Optionally, in the case that the first error does not satisfy the first preset condition, it indicates that the difference between the predicted load torque predicted by the torque observer and the actual load torque generated by the actual movement of the motor is large, and the accuracy of the predicted load torque is low, so the motor speed and the target braking torque need to be repeatedly updated, so that the obtained predicted load torque gradually approaches the actual load torque.

[0071] Optionally, the first preset condition includes any one of the following: the error is less than a predetermined value, and the error cannot continue to decrease.

[0072] Optionally, the first error between the predicted load torque and the actual load torque can be constructed as an error function as follows:

[0073]

[0074] wherein, is the first error; A is ; K is a feedback matrix; C is a constant; J is the rotational inertia of the whole vehicle; x is the ; is the ; ω r is the motor speed; T l is the predicted load torque; B is ; K is a feedback matrix, K = [k1 k2] T .

[0075] Optionally, the characteristic equation of the error function is as follows:

[0076]

[0077] In the characteristic equation (5), by selecting different k1 and k2, the pole configuration of A-KC can be satisfied, different poles result in different performances of the torque observer; and by selecting different k1 and k2, the first error can gradually satisfy the first preset condition.

[0078] In some embodiments, in the case that the first error does not satisfy the first preset condition, and / or a second error between the first predicted motor speed and the first actual motor speed does not satisfy the first preset condition, the motor speed is updated to the first predicted motor speed, and the target braking torque is updated to the target braking torque input to the torque observer this time, until the first error and the second error satisfy the first preset condition; wherein the first predicted motor speed is the motor speed predicted by the torque observer.

[0079] Optionally, please refer to Figure 2As shown, the torque observer calculates the first predicted motor speed while calculating the predicted load torque; in the case that the first error between the predicted load torque and the actual load torque does not satisfy the first preset condition, and the second error between the first predicted motor speed and the first actual motor speed does not satisfy the first preset condition, the target braking torque and the motor speed are updated to re-predict the predicted load torque and the first predicted motor speed until the first error and the second error satisfy the preset condition.

[0080] The first error and the second error are positively correlated, and the first error gradually decreases while the second error gradually decreases.

[0081] When the motor speed is updated to obtain the first predicted motor speed, the first predicted motor speed predicted by the torque observer last time is input into the torque observer as the motor speed for the next calculation, and this is repeated until the finally predicted first predicted motor speed is close to the first actual motor speed.

[0082] The vehicle control unit outputs the target braking torque, so when the torque observer updates the target braking torque each time, the target braking torque output by the vehicle in real time can be obtained from the vehicle control unit to update the target braking torque.

[0083] In some embodiments, when the first error satisfies the first preset condition, it can be determined that the predicted load torque is close to the actual load torque, and the accuracy of the predicted load torque is high, so the predicted load torque can be fed back to the speed loop of the vehicle as the target load torque.

[0084] Optionally, when the first error satisfies the first preset condition, the torque observer when the first error satisfies the first preset condition is taken as the target torque observer. Since the target torque observer is obtained after training and can output the predicted load torque close to the actual load torque, the prediction accuracy of the target torque observer is high, so in the subsequent process of stable driving of the vehicle, the target torque observer can predict the target load torque required by the vehicle each time it is parked on a slope according to the motor speed, the target braking torque and the vehicle moment of inertia output by the vehicle, without repeatedly updating and training the torque observer, and without repeatedly adjusting the PI parameters of the speed loop.

[0085] Optionally, since the target torque observer is obtained, the predicted load torque of the vehicle can be predicted for the vehicle under various conditions such as empty load, full load, half load, overload, and the predicted load torque obtained is written into the read-write storage chip Eeprom.

[0086] In some embodiments, when the first error and / or the second error satisfies the first preset condition, the predicted load torque can be taken as the target load torque.

[0087] In some embodiments, the target load torque refers to a torque that can achieve a good hill-holding effect after being superimposed on the torque output by the vehicle's speed loop.

[0088] In step S103 , the hill-holding torque is determined according to the target load torque and the torque output by the speed loop of the vehicle.

[0089] In some embodiments, the sum of the target load torque and the torque output by the vehicle speed loop may be used as the hill-holding torque.

[0090] In some embodiments, see Figure 3 The schematic diagram of the two double closed loops, the speed loop and the current loop, is shown in the figure. Figure 3 In the figure, ACR is the current regulator, ASR is the speed regulator, TG is the tachogenerator, TA is the current transformer, and UPE is the power electronic converter. The speed loop is the outer loop of the motor control system, controlling the motor speed to achieve both speed regulation and speed stability. The current loop is the inner loop of the motor control system, controlling the motor current to ensure faster startup.

[0091] In some cases, see Figure 4 As shown in the figure, when the vehicle is driving normally, the vehicle controller obtains the vehicle's current gear, speed, throttle and other signals to determine whether to issue a hill-holding command; the motor controller receives the hill-holding command output by the vehicle controller, and the hill-holding command carries the target braking torque; the motor controller performs zero-speed PI control according to the hill-holding command; at the same time, the negative gradient method is used to identify the vehicle's moment of inertia under acceleration conditions; the vehicle's moment of inertia is then input into the torque observer to observe the predicted load torque; the motor controller then combines the predicted load torque with the zero-speed PI control to output a hill-holding torque command, and the hill-holding torque command carries the hill-holding torque.

[0092] Optionally, the speed loop includes PI parameters, where the P parameter is a proportional coefficient, which is the ratio between the output value of the motor control system and the error value. The larger the proportional coefficient, the faster the response speed of the motor control system, but the stability of the motor control system is reduced; the I parameter is the integration time, which is the integration time of the motor control system for the error value. The larger the integration time, the slower the accumulation of the error value by the motor control system, the higher the stability of the motor control system, but the slower the response speed of the motor control system.

[0093] Optionally, see Figure 5As shown, for the design of the speed loop PI parameters and the current loop PI parameters, the current loop PI parameters have two, and the speed loop PI parameters also have two. The current loop bandwidth can be calculated first, and then the motor inductance and resistance parameters are obtained, and the current loop PI parameters are designed through the motor inductance, resistance and other parameters; then the damping parameter is obtained, and the speed loop PI parameters are designed according to the current loop bandwidth and the damping parameter. In this process, the current loop bandwidth can be selected as 500; when designing the speed loop PI parameters, the integral time can be fixed first, and different proportional coefficients are set, and finally the corresponding integral time and proportional coefficient are written into the read-write storage chip, so that when facing the vehicle parking condition, the corresponding integral time, proportional coefficient and predicted load torque can be quickly read from the read-write storage chip to realize the rapid parking of the vehicle.

[0094] In the related art, if a good parking effect is needed, the PI parameters of the speed loop need to be repeatedly adjusted, so that the parking torque output by the speed loop can achieve a good parking effect, and the good parking effect means that the vehicle can neither slide down the slope nor rush forward according to the parking torque.

[0095] Therefore, in order to avoid the adjustment cost caused by repeatedly adjusting the PI parameters of the speed loop, the embodiment of the present disclosure proposes to use a torque observer to predict a predicted load torque close to the actual load torque, so that since the predicted load torque directly given by the present disclosure is close to the actual load torque required by the motor driving the vehicle load, the parking torque obtained by combining the predicted load torque and the torque output by the speed loop can directly realize the parking of the vehicle. On the one hand, the predicted predicted load torque is directly used as the feedforward term of the speed loop, so that the PI parameters of the speed loop do not need to be repeatedly adjusted, thereby saving the time for adjusting the PI parameters of the speed loop, so that the parking torque can be obtained faster, and the parking time is shortened; on the other hand, after the parking time is shortened, the distance of the vehicle from rushing forward or sliding backward can be avoided.

[0096] Since the vehicle moment of inertia needs to be input into the torque observer as a known quantity when the predicted load torque is obtained, the predicted load torque can be obtained, therefore, the embodiment of the present disclosure also uses a negative gradient method to identify the vehicle moment of inertia, which needs to be obtained through the following steps:

[0097] In step S201, the vehicle moment of inertia is determined according to the target braking torque and the motor speed.

[0098] In some embodiments, step S201 includes the following sub-steps:

[0099] (1) input the target braking torque and the initial moment of inertia into the moment of inertia model to predict a second predicted motor speed.

[0100] Optionally, the moment of inertia model is constructed by taking the first motor speed, the second motor speed and the third motor speed as outputs of the moment of inertia model, and taking the first target braking torque and the second target braking torque as inputs of the moment of inertia model.

[0101] wherein the first motor speed is a motor speed of the motor at a first time, the second motor speed is a motor speed of the motor at a second time, and the third motor speed is a motor speed of the motor at a third time, the second time, the first time and the third time being arranged in time sequence; the first target braking torque is a target braking torque output by the vehicle controller at the first time, and the second target braking torque is a target braking torque output by the vehicle controller at the second time.

[0102] For example, a formula containing the moment of inertia of the vehicle is:

[0103]

[0104] wherein T e is the target braking torque; T l is the load torque; J is the moment of inertia of the vehicle; B is the viscous friction coefficient; and ω is the motor speed.

[0105] In the formula (6), it can be assumed that the viscous friction coefficient B is 0, and it can also be assumed that the sampling rate of the vehicle is high enough so that the load torque changes slowly, i.e. Therefore, the above formula (6) can be converted into the following formula (7), and the formula (7) is a moment of inertia model:

[0106]

[0107] wherein W m is the motor speed at the K-1 time (the first time); W m is the motor speed at the K-2 time (the second time); and W n is the motor speed at the K time (the third time). is a system parameter of the moment of inertia model, T is a calculation period of the moment of inertia model, and J is the moment of inertia of the vehicle; T e is the target braking torque at the K-1 time; T e is the target braking torque at the K-2 time.

[0108] As can be seen from the formula (7), in the moment of inertia model, the first motor speed W m at the first time, the second motor speed W m at the second time and the third motor speed W at the third time can be taken as inputs of the moment of inertia model.[K-2] the third motor speed W at the third time m [K] as an output of the moment of inertia model, the first target braking torque T e [K-1] the second target braking torque T e [K-2] as an output of the moment of inertia model, the third motor speed W The moment of inertia model is constructed as a system parameter.

[0109] The second time, the first time and the third time are arranged in time sequence, that is, the second time is before the first time, and the first time is before the third time.

[0110] In order to facilitate subsequent calculation of the whole vehicle moment of inertia, it can be assumed that -2W m [K-1]+W m [K-2]+W m [K] is y(k), assuming T e [K-1]-T e [K-2] is , assuming T / 2J is θ, and the above formula (7) is simplified to the following formula (8):

[0111]

[0112] Wherein, y(k) is the motor speed, is the target braking torque; θ is a system parameter, including the initial moment of inertia.

[0113] (2) if the third error between the second actual motor speed and the second predicted motor speed does not satisfy the second preset condition, updating the initial moment of inertia until the third error satisfies the second preset condition.

[0114] Optionally, if the third error between the second actual motor speed and the second predicted motor speed does not satisfy the second preset condition, it means that the difference between the second predicted motor speed obtained according to the initial moment of inertia and the actual second actual motor speed is large, that is, the initial moment of inertia is also inaccurate. At this time, the initial moment of inertia can be updated, and the updated initial moment of inertia is input into the above formula (8) to obtain the predicted second predicted motor speed.

[0115] Wherein, when updating the initial moment of inertia, it can be assumed that the initial moment of inertia is 0 at the first time of updating, the initial moment of inertia is 1 at the second time of updating, and so on until the third error obtained satisfies the second preset condition.

[0116] Wherein, the second preset condition includes any one of the following: the third error cannot continue to decrease, and the third error is less than a predetermined value.

[0117] The third error can be expressed by the following formula (9):

[0118]

[0119] In formula (9), ε(θ,K) is the third error; y[K] is the second actual motor speed; The second predicted motor speed is predicted by the moment of inertia model.

[0120] (3) Obtaining the vehicle's rotational inertia based on the third error when the second preset condition is met.

[0121] Optionally, based on the third error that satisfies the second preset condition, the first system coefficient of the moment of inertia model calculated and predicted in the last time, and the target braking torque input into the moment of inertia model calculated this time, the second system parameter of the moment of inertia model calculated and predicted this time is obtained; based on the second system parameter, the moment of inertia of the whole vehicle is obtained.

[0122] After updating the initial moment of inertia, the initial moment of inertia obtained when the third error satisfies the second preset condition may not be the accurate moment of inertia of the entire vehicle. To obtain a more accurate moment of inertia of the entire vehicle, the embodiment of the present disclosure further proposes calculating the moment of inertia of the entire vehicle using the following formula:

[0123]

[0124] In formula (10), is the second system parameter predicted by the moment of inertia model; is the first system parameter obtained by the last prediction of the moment of inertia model; P(K-1) is the weight of the criterion function at the previous moment; grad(A) is the gradient of the criterion function; A is the criterion function.

[0125] Among them, the criterion function can be:

[0126]

[0127] Substituting the above (11) into grad(A) in formula (10), we can get

[0128]

[0129] Substituting formula (12) into formula (10) yields the following formula for calculating the moment of inertia of the vehicle:

[0130]

[0131] It can be seen from formula (13) that the third error a first system parameter predicted by the last calculation and a target braking torque input into the moment of inertia model this time to obtain a second system parameter After obtaining the second system parameter, the whole vehicle moment of inertia is obtained according to the following formula (14):

[0132]

[0133] In formula (14), J is the whole vehicle moment of inertia, T is the sampling interval of the moment of inertia model, and T is the second system parameter.

[0134] As can be seen from formula (14), the calculation period of the moment of inertia model can be divided by the second system parameter to obtain the whole vehicle moment of inertia.

[0135] In some scenarios, as shown in FIG. 6, the whole vehicle controller can send an acceleration or deceleration instruction to the motor controller, and the motor controller controls the motor to accelerate or decelerate according to the acceleration or deceleration instruction. At the same time of controlling the motor to accelerate or decelerate, the whole vehicle moment of inertia of the whole vehicle is identified, which includes the motor moment of inertia and the load moment of inertia.

[0136] Through the above technical solution, the whole vehicle moment of inertia can be predicted, and then the whole vehicle moment of inertia is obtained without adjusting the speed loop PI parameter, and further, the problem of hill-holding or hill-charge caused by repeatedly adjusting the speed loop PI parameter is avoided.

[0137] Figure 7 is a block diagram of a hill-holding torque determination device according to an exemplary embodiment. Referring to Figure 7 The hill-holding torque determination device 700 includes a prediction module 710, a target load torque determination module 720, and a hill-holding torque determination module 730.

[0138] The prediction module 710 is configured to input the whole vehicle moment of inertia of the vehicle, the motor speed of the motor, and the target braking torque output by the whole vehicle controller into a torque observer to obtain a predicted load torque.

[0139] The target load torque determination module 720 is configured to, in a case where a first error between the predicted load torque and an actual load torque satisfies a first preset condition, take the predicted load torque when the first error satisfies the first preset condition as a target load torque.

[0140] The hill-holding torque determination module 730 is configured to determine a hill-holding torque according to the target load torque and a torque output by a speed loop of the vehicle.

[0141] ​Optionally, the hill-hold torque determination apparatus 700 comprises:

[0142] The updating module is configured to update the motor speed and the target brake torque when the first error does not satisfy the first preset condition until the first error satisfies the first preset condition.

[0143] Optionally, the updating module comprises:

[0144] The first updating submodule is configured to update the motor speed to the first predicted motor speed and update the target brake torque to the target brake torque input to the torque observer this time when the first error does not satisfy the first preset condition and / or a second error between the first predicted motor speed and the first actual motor speed does not satisfy the first preset condition until the first error and the second error satisfy the first preset condition; wherein the first predicted motor speed is a motor speed predicted by the torque observer.

[0145] Optionally, the hill-hold torque determination apparatus 700 comprises:

[0146] The moment of inertia calculation module is configured to determine the vehicle moment of inertia according to the target brake torque and the motor speed.

[0147] Optionally, the moment of inertia calculation module comprises:

[0148] The prediction submodule is configured to input the target brake torque and an initial moment of inertia into a moment of inertia model to predict a second predicted motor speed.

[0149] The second updating submodule is configured to update the initial moment of inertia when a third error between the second predicted motor speed and the second actual motor speed does not satisfy a second preset condition until the third error satisfies the second preset condition.

[0150] The first calculation submodule is configured to obtain the vehicle moment of inertia according to the third error when the second preset condition is satisfied.

[0151] Optionally, the first calculation submodule comprises:

[0152] The second calculation submodule is configured to obtain a second system parameter predicted by the moment of inertia model this time according to the third error when the second preset condition is satisfied, a first system coefficient predicted by the moment of inertia model last time, and the target brake torque input to the moment of inertia model this time.

[0153] The third calculation submodule is configured to obtain the vehicle moment of inertia according to the second system parameter.

[0154] Optionally, the hill-holding torque determination apparatus 700 comprises:

[0155] The construction module is configured to construct the moment of inertia model by taking the first motor speed, the second motor speed and the third motor speed as the output of the moment of inertia model, and taking the first target brake torque and the second target brake torque as the input of the moment of inertia model.

[0156] The first motor speed is the motor speed of the motor at a first time, the second motor speed is the motor speed of the motor at a second time, and the third motor speed is the motor speed of the motor at a third time. The second time, the first time and the third time are arranged in time sequence. The first target brake torque is the target brake torque output by the vehicle controller at the first time, and the second target brake torque is the target brake torque output by the vehicle controller at the second time.

[0157] Optionally, the hill-holding torque determination module 730 comprises:

[0158] The hill-holding torque determination sub-module is configured to take the sum of the target load torque and the torque output by the speed loop as the hill-holding torque.

[0159] As to the apparatus in the above-mentioned embodiments, the specific manner in which each module performs operations has been described in detail in the embodiments related to the method, and will not be described in detail here.

[0160] The present disclosure also provides a computer readable storage medium having stored thereon computer program instructions, which, when executed by a processor, implement the steps of the hill-holding torque determination method provided by the present disclosure.

[0161] Figure 8 is a block diagram of an apparatus 800 for determining hill-holding torque according to an exemplary embodiment. For example, the apparatus 800 can be an electric motor controller, a vehicle, or the like.

[0162] Referring to Figure 8 , the apparatus 800 can include one or more of the following components: a processing component 802, a memory 804, a power supply component 806, a multimedia component 808, an audio component 810, an input / output (I / O) interface 812, a sensor component 814, and a communication component 816.

[0163] The processing component 802 generally controls the overall operations of the device 800, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 802 can include one or more processors 820 to execute instructions to complete the above-mentioned all or part of the steps of the hill hold torque determination method. In addition, the processing component 802 can include one or more modules to facilitate the interaction between the processing component 802 and other components. For example, the processing component 802 can include a multimedia module to facilitate the interaction between the multimedia component 808 and the processing component 802.

[0164] The memory 804 is configured to store various types of data to support operations of the device 800. Examples of these data include instructions to operate any applications or methods on the device 800, contact data, phonebook data, messages, pictures, videos, and so on. The memory 804 can be implemented by any type of volatile or non-volatile storage devices or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk.

[0165] The power component 806 provides power to the various components of the device 800. The power component 806 can include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the device 800.

[0166] The multimedia component 808 includes a screen to provide an output interface between the device 800 and a user. In some embodiments, the screen can include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes the touch panel, the screen can be implemented as a touch screen to receive an input signal from a user. The touch panel includes one or more touch sensors to sense a touch, a slide, and a gesture on the touch panel. The touch sensors can not only sense a boundary of a touching or sliding action, but also detect duration and pressure related to the touching or sliding action. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. The front camera and / or the rear camera can receive external multimedia data when the device 800 is in an operating mode, such as a shooting mode or a video mode. Each of the front camera and the rear camera can be a fixed optical lens system or have a focal length and optical zoom capability.

[0167] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC) that is configured to receive an external audio signal when the device 800 is in an operation mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signal can be further stored in the memory 804 or transmitted via the communication component 816. In some embodiments, the audio component 810 also includes a speaker for outputting audio signals.

[0168] The input / output interface 812 provides an interface between the processing component 802 and peripheral interface modules, which can include a keypad, a click wheel, buttons, and so on. The buttons can include, but are not limited to, a home button, a volume button, a start button, and a lock button.

[0169] The sensor component 814 includes one or more sensors for providing status assessments of various aspects of the device 800. For example, the sensor component 814 can detect an open / closed position of the device 800, relative positioning of components, such as a display and a keypad of the device 800, a change of position of the device 800 or a component of the device 800, presence or absence of user contact with the device 800, changes in orientation or acceleration / deceleration

[0170] The communication component 816 is configured to facilitate wired or wireless communication between the device 800 and other devices. The device 800 can access a wireless network based on a corresponding communication standard, such as WiFi, 2G, or 3G, or a combination thereof. In an example embodiment, the communication component 816 receives broadcast signals or broadcast-related information from external broadcast management systems via a broadcast channel. In an example embodiment, the communication component 816 also includes a Near Field Communication (NFC) module to promote short-range communication. For example, the NFC module can be implemented based on Radio Frequency Identification (RFID) techniques, infrared data association (IrDA) techniques, ultra-wideband (UWB) techniques, Bluetooth (BT) techniques, and other techniques.

[0171] In an exemplary embodiment, the apparatus 800 can be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, micro-controllers, microprocessors, or other electronic components, for performing the hill-hold torque determination method described above.

[0172] In an exemplary embodiment, a non-transitory computer readable storage medium including instructions, such as the memory 804 including instructions, is also provided, which can be executed by the processor 820 of the apparatus 800 to complete the hill-hold torque determination method described above. For example, the non-transitory computer readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0173] The apparatus described above can be an independent electronic device, or can be a part of an independent electronic device, such as an integrated circuit (IC) or a chip in an embodiment. The integrated circuit can be an IC or a collection of multiple ICs. The chip can include, but is not limited to, a graphics processing unit (GPU), a central processing unit (CPU), a field programmable gate array (FPGA), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a system on chip (SoC), etc. The integrated circuit or chip can execute executable instructions (or code) to implement the hill-hold torque determination method described above. The executable instructions can be stored in the integrated circuit or chip, or can be obtained from other devices or apparatuses, such as a processor, a memory, and an interface for communicating with other devices included in the integrated circuit or chip. The executable instructions can be stored in the memory, and when executed by the processor, implement the hill-hold torque determination method described above. Alternatively, the integrated circuit or chip can receive executable instructions through the interface and transmit the executable instructions to the processor for execution, to implement the hill-hold torque determination method described above.

[0174] In another exemplary embodiment, there is also provided a computer program product comprising a computer program capable of being executed by a programmable apparatus, the computer program having code portions for performing the hill-hold torque determination method described above when executed by the programmable apparatus.

[0175] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the disclosure being indicated by the following claims.

[0176] It is to be understood that the disclosure is not limited to the precise construction described above and shown in the attached drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the disclosure is limited only by the claims that follow.

Claims

1. A method for determining hill-holding torque, characterized in that: Applied to a vehicle, the vehicle comprising a motor and a vehicle controller, the method comprising: Inputting the vehicle's rotational inertia, the motor speed of the motor, and the target braking torque output by the vehicle controller into a torque observer to obtain a predicted load torque; When a first error between the predicted load torque and the actual load torque satisfies a first preset condition, the predicted load torque when the first error satisfies the first preset condition is used as the target load torque; determining a hill-holding torque according to the target load torque and a torque output by a speed loop of the vehicle; Before inputting the vehicle moment of inertia of the vehicle, the motor speed of the motor, and the target braking torque output by the vehicle controller into the torque observer to obtain the predicted load torque, the method further includes: determining the vehicle moment of inertia according to the target braking torque and the motor speed; The determining the vehicle moment of inertia according to the target braking torque and the motor speed includes: Inputting the target braking torque and the initial moment of inertia into a moment of inertia model to predict a second predicted motor speed; If a third error between the second actual motor speed and the second predicted motor speed does not satisfy a second preset condition, updating the initial moment of inertia until the third error satisfies the second preset condition; The vehicle moment of inertia is obtained according to the third error when the second preset condition is met.

2. The method according to claim 1, characterized in that The method further comprises: When the first error does not satisfy a first preset condition, the motor speed and the target braking torque are updated until the first error satisfies the first preset condition.

3. The method according to claim 2, characterized in that When the first error does not satisfy a first preset condition, updating the motor speed and the target braking torque until the first error satisfies the first preset condition includes: When the first error does not satisfy the first preset condition, and / or the second error between the first predicted motor speed and the first actual motor speed does not satisfy the first preset condition, the motor speed is updated to the first predicted motor speed, and the target braking torque is updated to the target braking torque input to the torque observer this time, until the first error and the second error satisfy the first preset condition; wherein, the first predicted motor speed is the motor speed predicted by the torque observer.

4. The method according to claim 1, wherein Obtaining the vehicle moment of inertia according to the third error when the second preset condition is satisfied includes: Obtaining a second system parameter of the moment of inertia model calculated and predicted this time based on the third error that meets the second preset condition, the first system coefficient of the moment of inertia model calculated and predicted last time, and the target braking torque input into the moment of inertia model this time; The vehicle moment of inertia is obtained according to the second system parameter.

5. The method according to claim 1, wherein The moment of inertia model is constructed by the following steps: The first motor speed, the second motor speed, and the third motor speed are used as outputs of the moment of inertia model, and the first target braking torque and the second target braking torque are used as inputs of the moment of inertia model to construct the moment of inertia model; Among them, the first motor speed is the motor speed of the motor at the first moment, the second motor speed is the motor speed of the motor at the second moment, and the third motor speed is the motor speed of the motor at the third moment. The second moment, the first moment and the third moment are arranged in chronological order; the first target braking torque is the target braking torque output by the vehicle controller at the first moment, and the second target braking torque is the target braking torque output by the vehicle controller at the second moment.

6. The method according to claim 1, characterized in that The step of determining the hill-holding torque according to the target load torque and the torque output by the speed loop of the vehicle includes: The sum of the target load torque and the torque output by the speed loop is used as the hill-holding torque.

7. A device for determining torque on a hill, characterized in that: Applied to a vehicle, the vehicle comprising a motor and a vehicle controller, including: a prediction module configured to input the vehicle moment of inertia of the vehicle, the motor speed of the motor, and the target braking torque output by the vehicle controller into a torque observer to obtain a predicted load torque; a target load torque determination module configured to, when a first error between the predicted load torque and the actual load torque satisfies a first preset condition, use the predicted load torque when the first error satisfies the first preset condition as the target load torque; a hill-holding torque determination module, configured to determine the hill-holding torque according to the target load torque and the torque output by the speed loop of the vehicle; Before inputting the vehicle moment of inertia, the motor speed of the motor, and the target braking torque output by the vehicle controller into the torque observer to obtain the predicted load torque, the prediction module is further configured to: determining the vehicle moment of inertia according to the target braking torque and the motor speed; The determining the vehicle moment of inertia according to the target braking torque and the motor speed includes: Inputting the target braking torque and the initial moment of inertia into a moment of inertia model to predict a second predicted motor speed; If a third error between the second actual motor speed and the second predicted motor speed does not satisfy a second preset condition, updating the initial moment of inertia until the third error satisfies the second preset condition; The vehicle moment of inertia is obtained according to the third error when the second preset condition is met.

8. A motor controller, characterized in that: The motor controller executes the steps of the method according to any one of claims 1 to 6.

9. A vehicle, characterized in that: The vehicle is equipped with the motor controller according to claim 8.

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