Cam profile determination method and related hardware

Abstract

The present invention discloses a cam profile determination method and related hardware, wherein the method comprises: obtaining the starting angle, the ending angle, the starting rotation parameter corresponding to the starting angle, and the starting lift corresponding to the starting angle of the cam input by the user; determining the constraint conditions satisfied by the cam profile between the starting angle and the ending angle according to the starting angle, the ending angle, the starting rotation parameter, and the starting lift; determining multiple candidate cam profiles that meet the constraint conditions, and determining the final cam profile from the candidate cam profiles according to the maximum acceleration parameter corresponding to each candidate cam profile. The constraint conditions of the cam profile can be determined according to the angle range input by the user and the design target at the angle, and the cam profile can be determined and screened according to the constraint conditions, so that the cam profile is finally made smoother and continuous at the connection of each segment, simplifying the calculation process.

Description

Technical Field

[0001] The present invention relates to the field of mechanical technology, and in particular to a cam profile determination method and related hardware. Background Art

[0002] A cam is a part used to achieve mechanical rotation or sliding, used to transmit motion through rotation to a roller moving close to its edge or a needle bar moving freely on a groove surface, or to receive force from the aforementioned roller and needle bar.

[0003] For the camshaft of the engine, the cam profile needs to be designed in sections according to the working requirements of the engine. Figure 1 As shown in the figure, the profile of the camshaft of the engine can be divided into the positive power segment profile, the brake profile fitting design segment profile, the brake segment profile and other parts. The positive power segment profile is used to control the opening and closing of the valve when the engine is doing positive work; the brake segment profile is used to control the opening of the valve when the piston is compressed to the top dead center of the engine, releasing the braking energy of the compressed gas, so that the engine can act as a brake to provide braking effect to the whole vehicle when not doing work, and generate higher braking work during braking; the brake profile fitting design segment profile is used to control the seating of the valve after the positive power profile ends. In the existing cam profile design process, due to the different design goals of each cam profile segment, each cam profile segment needs to be repeatedly tried based on manual experience to ensure the continuity of the curve at the connection of each cam segment, and the design process is relatively complicated. Summary of the invention

[0004] The embodiment of the present invention provides a cam profile determination method and related hardware, which are used to provide a simple solution to obtain appropriate cam profiles of various sections.

[0005] In a first aspect, an embodiment of the present invention provides a cam profile determination method, comprising:

[0006] Obtaining the starting angle, the ending angle, the starting rotation parameter corresponding to the starting angle, and the starting lift corresponding to the starting angle of the cam input by the user;

[0007] Determining a constraint condition satisfied by the cam profile between the starting rotation angle and the ending rotation angle according to the starting rotation angle, the ending rotation angle, the starting rotation parameter and the starting lift;

[0008] A plurality of candidate cam profiles meeting the constraint conditions are determined, and a final cam profile is determined from the candidate cam profiles according to maximum acceleration parameters corresponding to the candidate cam profiles.

[0009] Optionally, the candidate cam profile includes a first type of shape control parameter set and a second type of shape control parameter set for controlling the shape of the candidate cam profile; the constraint condition includes a first constraint condition and a second constraint condition;

[0010] Determining a plurality of candidate cam profiles that meet the constraint conditions includes:

[0011] determining a first type of shape control parameter set of the cam profile according to the first constraint condition, and determining a first candidate cam profile according to the first type of shape control parameter set;

[0012] Select a first candidate value of the target quantity from the random number value interval;

[0013] Determine a plurality of second-type shape control parameter sets according to the first candidate values;

[0014] For any of the second-type shape control parameter sets, determining a second candidate cam profile according to the first candidate cam profile and the second-type shape control parameter set;

[0015] Deleting the second candidate cam profile that does not meet the second constraint condition from the second candidate cam profile, and generating the same number of second candidate values ​​as the deleted second candidate cam profile in the random number value interval;

[0016] For any second candidate value, determine a set of second-type shape control parameter sets based on the second candidate value, and return to the step of determining a second candidate cam profile based on the first candidate cam profile and the second-type shape control parameter set, until all determined second candidate cam profiles satisfy the second constraint condition.

[0017] Optionally, the random number value interval and the target number are determined according to the angle interval length of the cam profile and a preset cam profile maximum acceleration parameter, wherein the angle interval length is the difference between the end angle and the start angle.

[0018] Optionally, the first constraint condition includes:

[0019] The lift at the starting angle is equal to the starting lift;

[0020] The rotation parameter at the starting rotation angle is equal to the starting rotation parameter;

[0021] The lift at the end corner is equal to the end lift;

[0022] The rotation parameter at the end corner is 0;

[0023] The acceleration parameter at the end corner is 0;

[0024] The jerk parameter at the end corner is 0.

[0025] Optionally, the second constraint condition includes:

[0026] The lift at the starting angle is equal to the starting lift;

[0027] The rotation parameter of the cam profile is less than a preset rotation parameter threshold;

[0028] The acceleration parameter of the cam profile is less than a preset acceleration parameter threshold;

[0029] The jerk parameter of the cam profile is less than a preset jerk parameter threshold.

[0030] Optionally, after determining the final cam profile from the candidate cam profiles, the method further comprises:

[0031] The coordinates of each point on the cam profile are generated and output in a table form.

[0032] In a second aspect, based on the same inventive concept, an embodiment of the present invention further provides a cam profile determination device, comprising:

[0033] A user input module, used to obtain the starting angle, the ending angle, the starting rotation parameter corresponding to the starting angle, and the starting lift corresponding to the starting angle of the cam input by the user;

[0034] A constraint condition determination module, used for determining the constraint condition satisfied by the cam profile between the starting rotation angle and the ending rotation angle according to the starting rotation angle, the ending rotation angle, the starting rotation parameter and the starting lift;

[0035] The cam profile determination module is used to determine a plurality of candidate cam profiles that meet the constraint conditions, and determine a final cam profile from the candidate cam profiles according to the maximum acceleration parameters corresponding to the candidate cam profiles.

[0036] In a third aspect, based on the same inventive concept, an embodiment of the present invention further provides an electronic device, comprising: a processor and a memory for storing instructions executable by the processor;

[0037] Wherein, the processor is configured to execute the instructions to implement the cam profile determination method as described in the first aspect.

[0038] In a fourth aspect, based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program is used to implement the cam profile determination method as described in the first aspect.

[0039] In a fifth aspect, based on the same inventive concept, an embodiment of the present invention further provides a cam, wherein at least a portion of the profile of the cam is determined by using the cam profile determination method as described in the first aspect.

[0040] The beneficial effects of the present invention are as follows:

[0041] The cam profile determination method and related hardware provided in the embodiment of the present invention can determine the constraints of the cam profile according to the angle range input by the user and the design target at the angle, and determine and screen the cam profile according to the constraints, ultimately making the cam profile smoother and continuous at the connection points of each segment, thereby simplifying the calculation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A cam profile diagram of a cam provided by an embodiment of the present invention;

[0043] Figure 2 One of the flow charts of the cam profile determination method provided in an embodiment of the present invention;

[0044] Figure 3 A partial flow chart of a cam profile determination method provided by an embodiment of the present invention;

[0045] Figure 4 A second flowchart of a cam profile determination method provided by an embodiment of the present invention;

[0046] Figure 5 A schematic diagram of the structure of a cam profile determination device provided in an embodiment of the present invention;

[0047] Figure 6 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention;

[0048] Figure 7 A cam profile diagram of a cam provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the accompanying drawings and examples. However, the exemplary embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the exemplary embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained using the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportions.

[0050] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application and is not intended to limit the scope of the present application. The scope of protection of the present application shall be determined by the definition of the attached claims.

[0051] The cam profile determination method and related hardware provided by the embodiment of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0052] In a first aspect, an embodiment of the present invention provides a cam profile determination method, such as Figure 2 As shown, including:

[0053] S110, obtaining a starting angle, an ending angle, a starting rotation parameter corresponding to the starting angle, and a starting lift corresponding to the starting angle of the cam input by a user.

[0054] Wherein, the rotation parameter is the first-order derivative of the cam profile with respect to the rotation angle. When the angular velocity of the cam is a constant value, the rotation parameter can reflect the velocity of the cam.

[0055] In the specific implementation process, the starting angle and the ending angle input by the user can be the angle of the cam itself (effective value 0-360°), or the crankshaft angle of the corresponding engine (effective value 0-720°). The crankshaft angle will be used as an example for explanation below.

[0056] S120. Determine, based on the starting rotation angle, the ending rotation angle, the starting rotation parameter, and the starting lift, a constraint condition satisfied by the cam profile between the starting rotation angle and the ending rotation angle.

[0057] S130: Determine a plurality of candidate cam profiles that meet the constraint conditions.

[0058] S140 , determining a final cam profile from the candidate cam profiles according to the maximum acceleration parameters corresponding to the candidate cam profiles.

[0059] Wherein, the acceleration parameter is the second-order derivative of the cam profile with respect to the rotation angle. When the angular velocity of the cam is a constant value, the acceleration parameter can reflect the acceleration of the cam.

[0060] In this way, by adopting the cam profile determination method, the constraints of the cam profile can be determined according to the angle range input by the user and the design target at the angle, and the cam profile can be determined and screened according to the constraints, so that the cam profile is finally made smoother and continuous at the connection points of each segment, simplifying the calculation process.

[0061] Optionally, after step S140, the method further includes:

[0062] S150, generating coordinates of each point on the cam profile and outputting them in a table form.

[0063] In a specific implementation process, the coordinates of each point on the cam profile can be output in the form of a table in a format such as Excel, so that production equipment such as a CNC machining center can perform manufacturing according to the coordinate table.

[0064] Furthermore, the candidate cam profile includes a first type of shape control parameter set and a second type of shape control parameter set for controlling the shape of the candidate cam profile; and the constraint condition includes a first constraint condition and a second constraint condition.

[0065] like Figure 3 As shown, in step S130, determining a plurality of candidate cam profiles that meet the constraint conditions specifically includes:

[0066] S131. Determine a first type of shape control parameter set of the cam profile according to the first constraint condition, and determine a first candidate cam profile according to the first type of shape control parameter set.

[0067] Optionally, the first constraint condition includes:

[0068] (1) The lift at the starting angle is equal to the starting lift.

[0069] Let the starting angle be θ min , the end angle is θ max , the cam profile is Y(θ), the starting rotation parameter is v0, and the starting lift is H0. Then the first constraint condition is specifically expressed as follows:

[0070] Y(θ)|θ=θ min =H0

[0071] (2) The rotation parameter at the starting angle is equal to the starting rotation parameter.

[0072] In the specific implementation process, this first constraint condition can be specifically expressed as follows:

[0073] Y′(θ)|θ=θ min =v0

[0074] (3) The lift at the end corner is equal to the end lift.

[0075] The end lift is denoted as H1, that is, the first constraint condition of this item is specifically expressed as follows:

[0076] Y(θ)|θ=θ max =H1

[0077] In a specific implementation process, the end lift H1 can be set to 0.

[0078] (4) The rotation parameter at the end corner is 0.

[0079] That is, the first constraint condition is specifically expressed as follows:

[0080] Y′(θ)|θ=θ max =0

[0081] (5) The acceleration parameter at the end corner is 0.

[0082] That is, the first constraint condition is specifically expressed as follows:

[0083] Y″(θ)|θ=θ max =0

[0084] This first constraint condition constrains the cam profile to have no rigid impact at the end corner.

[0085] (6) The jerk parameter at the end corner is 0.

[0086] Wherein, the jerk parameter is the third-order derivative of the cam profile with respect to the rotation angle. When the angular velocity of the cam is a constant value, the jerk parameter can reflect the jerk degree of the cam.

[0087] That is, the first constraint condition is specifically expressed as follows:

[0088] Y″′(θ)|θ=θ max =0

[0089] This first constraint condition constrains the cam profile to have no flexible impact at the end corner.

[0090] For a cam profile expression of a specified form, a corresponding set of equations can be formed through the above six first constraints, and the first type of shape control parameter set of the cam profile is obtained by solving the set of equations, thereby obtaining a first candidate cam profile that determines the numerical values ​​of each first type of shape control parameter in the first type of shape control parameter set.

[0091] S132. Select a first candidate value of the target quantity from the random number value interval.

[0092] S133. Determine a plurality of second-type shape control parameter sets according to the first candidate values.

[0093] S134. Select a set of the second-type shape control parameters without repetition.

[0094] If the step S134 successfully selects one of the second-type shape control parameter sets, execute step S135 ; if the step S134 selects all of the second-type shape control parameter sets, execute step S136 .

[0095] S135, determining a second candidate cam profile according to the first candidate cam profile and the second set of shape control parameters. Return to step S134.

[0096] When the first type of shape control parameter set and the second type of shape control parameter set are known, the second candidate cam profile is uniquely determined.

[0097] S136: Determine whether all of the second candidate cam profiles meet the second constraint condition.

[0098] If the result of step S136 is yes, execute step S140; if the result of step S136 is no, execute step S137.

[0099] Optionally, the second constraint condition includes:

[0100] (1) The lift at the starting corner is equal to the starting lift set by the user.

[0101] (2) The rotation parameter of the cam profile is less than a preset rotation parameter threshold.

[0102] (3) The acceleration parameter of the cam profile is less than a preset acceleration parameter threshold.

[0103] (4) The jerk parameter of the cam profile is less than a preset jerk parameter threshold.

[0104] S137, deleting the second candidate cam profiles that do not meet the second constraint condition from the second candidate cam profiles, and generating a number of second candidate values ​​on the random number value interval that is equal to the number of the deleted second candidate cam profiles.

[0105] S138. Select one of the second candidate values ​​without repetition.

[0106] If the step S138 successfully selects one of the second candidate values, execute step S139; if the step S138 has selected all of the second candidate values, return to the step S136.

[0107] S139: Determine a set of second-type shape control parameter sets according to the second candidate values. Return to step S138.

[0108] As an optional implementation, the random number value interval and the target number are determined according to user settings.

[0109] As another optional implementation, the random number value interval and the target number are determined according to the angle interval length of the cam profile and the preset acceleration parameter threshold, wherein the angle interval length is the difference between the end angle and the start angle.

[0110] For example, the random number value interval is [1,n max ], where n max Satisfies the following relationship:

[0111]

[0112] Among them, θ T =θ max -θ min ,θ min is the starting angle, θ max is the end angle, a max It is the preset acceleration parameter threshold of the preset cam profile.

[0113] For example, the target number num satisfies the following relationship:

[0114]

[0115] or,

[0116]

[0117] Among them, θ T =θ max -θ min ,θ min is the starting angle, θ max is the end angle, a max It is the preset acceleration parameter threshold of the preset cam profile. It means to round x down to an integer. It means to round x upwards.

[0118] Furthermore, the cam profile satisfies the following form:

[0119]

[0120] Wherein, Y(θ) is the lift of the cam profile; θ is the cam rotation angle; θ T is the length of the specified cam angle interval, θT =θ max -θ min ; The first type of shape control parameter set includes first type of shape control parameters c0, c1, c2, c3, c4, c5; the second type of shape control parameter set includes second type of shape control parameters p, q, r, s.

[0121] The step S133, determining a plurality of second-type shape control parameter sets according to the first candidate values, specifically includes:

[0122] According to the rule of selecting four first candidate values ​​from the first candidate values ​​in ascending order as the second type of shape control parameters p, q, r, s, a second type of shape control parameter is obtained, and the A second set of shape control parameters.

[0123] The step S139, determining a set of second-type shape control parameter sets according to the second candidate values, specifically includes:

[0124] The second candidate value n is used to determine the second type of shape control parameters p, q, r, s according to the following relationship:

[0125]

[0126] The following is a specific implementation of the cam profile determination method provided by the embodiment of the present invention when the cam profile is in the form of the above-mentioned high-order pentaminar (eg Figure 4 shown):

[0127] S210, obtaining a starting angle, an ending angle, a starting rotation parameter corresponding to the starting angle, and a starting lift corresponding to the starting angle of the cam input by a user.

[0128] S220. Determine a first constraint condition and a second constraint condition satisfied by the cam profile between the starting angle and the ending angle according to the starting angle, the ending angle, the starting rotation parameter, and the starting lift.

[0129] The first constraint condition includes:

[0130] (1) The lift at the starting angle is equal to the starting lift.

[0131] (2) The rotation parameter at the starting angle is equal to the starting rotation parameter.

[0132] (3) The lift at the end corner is equal to the end lift.

[0133] (4) The rotation parameter at the end corner is 0.

[0134] (5) The acceleration parameter at the end corner is 0.

[0135] (6) The jerk parameter at the end corner is 0.

[0136] The second constraint condition includes:

[0137] (1) The lift at the starting corner is equal to the starting lift set by the user.

[0138] (2) The rotation parameter of the cam profile is less than a preset rotation parameter threshold of 2 mm / deg.

[0139] (3) The acceleration parameter of the cam profile is less than the preset acceleration parameter threshold of 18 mm / deg 2 .

[0140] (4) The cam profile has a jerk parameter less than a preset jerk parameter threshold of 1000 mm / deg 3 .

[0141] S231. Determine a first type of shape control parameter set of the cam profile according to the first constraint condition, and determine a first candidate cam profile according to the first type of shape control parameter set.

[0142] S232: Select a first candidate value of the target quantity from a random number value interval. The random number value interval is [1, n max ], where n max Satisfies the following relationship:

[0143]

[0144] The target number num satisfies the following relationship:

[0145]

[0146] S233, according to the rule of selecting four first candidate values ​​from the first candidate values ​​in ascending order as the second type of shape control parameters p, q, r, s, a second type of shape control parameter is obtained, and determining A second set of shape control parameters.

[0147] θ T =θ max -θ min ,θ min is the starting angle, θ max is the end angle, a max It is the preset acceleration parameter threshold of the preset cam profile.

[0148] S234. Select a set of the second-type shape control parameters without repetition.

[0149] If the step S234 successfully selects one of the second-type shape control parameter sets, execute step S235; if the step S234 selects all of the second-type shape control parameter sets, execute step S236.

[0150] S235: Determine a second candidate cam profile according to the first candidate cam profile and the second set of shape control parameters. Return to step S234.

[0151] When the first type of shape control parameter set and the second type of shape control parameter set are known, the second candidate cam profile is uniquely determined.

[0152] S236: Determine whether all of the second candidate cam profiles meet the second constraint condition.

[0153] If the result of step S236 is yes, execute step S240; if the result of step S236 is no, execute step S237.

[0154] S237, deleting the second candidate cam profiles that do not meet the second constraint condition from the second candidate cam profiles, and generating a number of second candidate values ​​on the random number value interval that is equal to the number of the deleted second candidate cam profiles.

[0155] S238. Select one of the second candidate values ​​without repetition.

[0156] If the step S238 successfully selects one of the second candidate values, execute step S239; if the step S238 has selected all of the second candidate values, return to step S236.

[0157] S239: Determine a set of second-type shape control parameter sets according to the second candidate value, wherein the second candidate value n and the second-type shape control parameter set satisfy the following relationship:

[0158]

[0159] S240 , determining a final cam profile from the candidate cam profiles according to the maximum acceleration parameters corresponding to the candidate cam profiles.

[0160] S250, generating coordinates of each point on the cam profile and outputting them in a table form.

[0161] In the second aspect, based on the same inventive concept, the embodiment of the present invention further provides a cam profile determination device, such as Figure 5 As shown, including:

[0162] The user input module M1 is used to obtain the starting angle, the ending angle, the starting rotation parameter corresponding to the starting angle, and the starting lift corresponding to the starting angle of the cam input by the user;

[0163] A constraint condition determination module M2, for determining a constraint condition satisfied by the cam profile between the starting angle and the ending angle according to the starting angle, the ending angle, the starting rotation parameter and the starting lift;

[0164] The cam profile determination module M3 is used to determine a plurality of candidate cam profiles that meet the constraint conditions, and determine a final cam profile from the candidate cam profiles according to the maximum acceleration parameters corresponding to the candidate cam profiles.

[0165] Optionally, the candidate cam profile includes a first type of shape control parameter set and a second type of shape control parameter set for controlling the shape of the candidate cam profile; the constraint condition includes a first constraint condition and a second constraint condition;

[0166] Determining a plurality of candidate cam profiles that meet the constraint conditions includes:

[0167] determining a first type of shape control parameter set of the cam profile according to the first constraint condition, and determining a first candidate cam profile according to the first type of shape control parameter set;

[0168] Select a first candidate value of the target quantity from the random number value interval;

[0169] Determine a plurality of second-type shape control parameter sets according to the first candidate values;

[0170] For any of the second-type shape control parameter sets, determining a second candidate cam profile according to the first candidate cam profile and the second-type shape control parameter set;

[0171] Deleting the second candidate cam profile that does not meet the second constraint condition from the second candidate cam profile, and generating the same number of second candidate values ​​as the deleted second candidate cam profile in the random number value interval;

[0172] For any second candidate value, determine a set of second-type shape control parameter sets based on the second candidate value, and return to the step of determining a second candidate cam profile based on the first candidate cam profile and the second-type shape control parameter set, until all determined second candidate cam profiles satisfy the second constraint condition.

[0173] Optionally, the random number value interval and the target number are determined according to the angle interval length of the cam profile and a preset cam profile maximum acceleration parameter, wherein the angle interval length is the difference between the end angle and the start angle.

[0174] Optionally, the first constraint condition includes:

[0175] The lift at the starting angle is equal to the starting lift;

[0176] The rotation parameter at the starting rotation angle is equal to the starting rotation parameter;

[0177] The lift at the end corner is equal to the end lift;

[0178] The rotation parameter at the end corner is 0;

[0179] The acceleration parameter at the end corner is 0;

[0180] The jerk parameter at the end corner is 0.

[0181] Optionally, the second constraint condition includes:

[0182] The lift at the starting angle is equal to the starting lift;

[0183] The rotation parameter of the cam profile is less than a preset rotation parameter threshold;

[0184] The acceleration parameter of the cam profile is less than a preset acceleration parameter threshold;

[0185] The jerk parameter of the cam profile is less than a preset jerk parameter threshold.

[0186] Optionally, the device further comprises:

[0187] The output module M4 is used to generate the coordinates of each point on the cam profile and output them in a table form.

[0188] It should be understood that the above-described embodiment of the automatic transmission control device is merely illustrative. For example, the division of the modules is merely a logical function division. There may be other division methods in actual implementation, such as multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. The functional modules in the embodiment may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may be stored in a computer-readable storage medium.

[0189] Since the principle of solving the problem by the cam profile determination device is basically consistent with that of the cam profile determination method, the implementation of the cam profile determination device can refer to the implementation of the cam profile determination method, which will not be described in detail here.

[0190] In a third aspect, based on the same inventive concept, an embodiment of the present invention further provides an electronic device, such as Figure 6 As shown, it includes: a processor and a memory for storing instructions executable by the processor;

[0191] Wherein, the processor is configured to execute the instructions to implement the cam profile determination method as described in the first aspect.

[0192] In the specific implementation process, the device may have relatively large differences due to different configurations or performances, and may include one or more processors 110, memory 120, and computer-readable storage medium 130. The memory 120 and / or computer-readable storage medium 130 include one or more applications 131 or data 132. The memory 120 and / or computer-readable storage medium 130 may also include one or more operating systems 133, such as Windows, Mac OS, Linux, IOS, Android, Unix, FreeBSD, etc. Among them, the memory 120 and the computer-readable storage medium 130 may be short-term storage or persistent storage. The application 131 may include one or more modules ( Figure 6 ), each module may include a series of instruction operations. Further, the processor 110 may be configured to communicate with the computer-readable storage medium 130, and execute a series of instruction operations in the storage medium 130 on the device. The device may also include one or more power supplies ( Figure 6 ); one or more network interfaces 140, the network interface 140 including a wired network interface 141 and / or a wireless network interface 142; one or more input / output interfaces 143. In a fourth aspect, based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and the computer program is used to implement the cam profile determination method as described in the first aspect.

[0193] In a fifth aspect, based on the same inventive concept, an embodiment of the present invention further provides a computer program product, including a computer program, wherein the computer program is used to implement the cam profile determination method as described in the first aspect.

[0194] In a sixth aspect, based on the same inventive concept, an embodiment of the present invention further provides a cam, wherein at least a portion of the profile of the cam is determined using the cam profile determination method as described in the first aspect.

[0195] For example, an embodiment of the present invention provides an engine cam, wherein the positive power section profile of the engine cam (such as Figure 7 As shown in FIG. 1 , the cam profile is obtained by using the cam profile determination method described in the first aspect. For another example, an embodiment of the present invention provides another engine cam, wherein the brake profile of the engine cam fits the design segment profile (such as Figure 1 (as shown) is obtained using the cam profile determination method described in the first aspect.

[0196] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0197] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0198] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0199] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0200] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A cam profile determination method, characterized in that: The cam profile includes at least a positive power segment, a braking profile fitting design segment, and a braking segment in the rotation direction; the method is used to determine a cam profile of a target profile segment; the target profile segment of the cam profile satisfies the following form: Wherein, θ is the cam angle; Y(θ) is the lift of the cam profile; θ min The starting angle of the cam input by the user; θ T =θ max -θ min ,θ max is the end angle of the cam input by the user; c0, c1, c2, c3, c4, c5 are the first type of shape control parameters; p, q, r, s are the second type of shape control parameters; The method comprises: Get the starting angle θ of the cam input by the user min 、End angle θ max , a starting rotation parameter corresponding to the starting angle and a starting lift corresponding to the starting angle; Determine, according to the starting rotation angle, the ending rotation angle, the starting rotation parameter and the starting lift, the constraint condition satisfied by the cam profile between the starting rotation angle and the ending rotation angle; the constraint condition includes a first constraint condition and a second constraint condition; determining a first type of shape control parameter set of the cam profile according to the first constraint condition, and determining a first candidate cam profile according to the first type of shape control parameter set; Select the first candidate value of the target number num from the random number value interval; According to the rule of selecting four first candidate values ​​from the first candidate values ​​of the target number num in ascending order as the second type of shape control parameters p, q, r, s, a second type of shape control parameter is obtained, and the A set of second-class shape control parameters; For any of the second-type shape control parameter sets, determining a second candidate cam profile according to the first candidate cam profile and the second-type shape control parameter set; Deleting the second candidate cam profile that does not meet the second constraint condition from the second candidate cam profile, and generating the same number of second candidate values ​​as the deleted second candidate cam profile in the random number value interval; For any second candidate value, determine a set of second type shape control parameter sets {p, q, r, s} according to the second candidate value, and return to the step of determining a second candidate cam profile according to the first candidate cam profile and the second type shape control parameter set until all the determined second candidate cam profiles meet the second constraint condition; determining a final cam profile from the candidate cam profiles according to the maximum acceleration parameter corresponding to each candidate cam profile; The random number range is [1,n max ], where n max Satisfies the following relationship: The target number num satisfies the following relationship: or, Among them, θ T =θ max -θ min ,θ min is the starting angle, θ max is the end angle, a max The preset acceleration parameter threshold for the preset cam profile, It means to round x down to an integer. It means to round x upwards; For any second candidate value n, a set of the second type shape control parameters p, q, r, s is determined according to the following relationship: 。 2. The method according to claim 1, characterized in that The first constraint condition includes: The lift at the starting angle is equal to the starting lift; The rotation parameter at the starting rotation angle is equal to the starting rotation parameter; The lift at the end corner is equal to the end lift; The rotation parameter at the end corner is 0; The acceleration parameter at the end corner is 0; The jerk parameter at the end corner is 0.

3. The method according to claim 1, characterized in that The second constraint condition includes: The lift at the starting angle is equal to the starting lift; The rotation parameter of the cam profile is less than a preset rotation parameter threshold; The acceleration parameter of the cam profile is less than a preset acceleration parameter threshold; The jerk parameter of the cam profile is less than a preset jerk parameter threshold.

4. The method according to claim 1, characterized in that After determining a final cam profile from the candidate cam profiles, the method further includes: The coordinates of each point on the cam profile are generated and output in Excel form.

5. A cam profile determination device, characterized in that: The cam profile includes at least a positive power segment, a braking profile fitting design segment, and a braking segment in the rotation direction; the device is used to determine the cam profile of the target profile segment; the target profile segment of the cam profile satisfies the following form: Wherein, θ is the cam angle; Y(θ) is the lift of the cam profile; θ min The starting angle of the cam input by the user; θ T =θ max -θ min ,θ max is the end angle of the cam input by the user; c0, c1, c2, c3, c4, c5 are the first type of shape control parameters; p, q, r, s are the second type of shape control parameters; The cam profile determining device comprises: The user input module is used to obtain the starting angle θ of the cam input by the user. min 、End angle θ max , a starting rotation parameter corresponding to the starting angle and a starting lift corresponding to the starting angle; a constraint condition determination module, for determining the constraint condition satisfied by the cam profile between the starting rotation angle and the ending rotation angle according to the starting rotation angle, the ending rotation angle, the starting rotation parameter and the starting lift; the constraint condition includes a first constraint condition and a second constraint condition; A cam profile determination module is used to determine a first type of shape control parameter set of the cam profile according to the first constraint condition, and to determine a first candidate cam profile according to the first type of shape control parameter set; select a first candidate value of a target number num from a random number value interval; select four first candidate values ​​from the first candidate values ​​of the target number num in order from small to large as the second type of shape control parameters p, q, r, s, to obtain a rule for the second type of shape control parameters, and determine a second type of shape control parameter set; for any of the second type of shape control parameter sets, determine a second candidate cam profile according to the first candidate cam profile and the second type of shape control parameter set; delete the second candidate cam profile that does not meet the second constraint condition from the second candidate cam profile, and generate a second candidate value equal to the deleted second candidate cam profile in the random number value interval; for any of the second candidate values, determine a set of second type of shape control parameter sets {p, q, r, s} according to the second candidate value, and return to the step of determining a second candidate cam profile according to the first candidate cam profile and the second type of shape control parameter set until all the determined second candidate cam profiles meet the second constraint condition; determine the final cam profile from the candidate cam profiles according to the maximum acceleration parameter corresponding to each candidate cam profile; The random number range is [1,n max ], where n max Satisfies the following relationship: The target number num satisfies the following relationship: or, Among them, θ T =θ max -θ min ,θ min is the starting angle, θ max is the end angle, a max The preset acceleration parameter threshold for the preset cam profile, It means to round x down to an integer. It means to round x upwards; For any second candidate value n, a set of the second type shape control parameters p, q, r, s is determined according to the following relationship:

6. An electronic device, characterized in that: include: a processor and a memory for storing instructions executable by the processor; Wherein, the processor is configured to execute the instructions to implement the cam profile determination method as described in any one of claims 1-4.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is used to implement the cam profile determination method according to any one of claims 1 to 4.

8. A cam, characterized in that: At least part of the profile of the cam is determined by using the cam profile determination method as described in any one of claims 1-4.

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