Guide des Servomoteurs¶
Terme
- Servomoteurs¶
A small DC motor attached to servo gears that is very finely controllable and interfaces via a 3 wire PWM connector. Servos are generally used in FTC® for high-precision applications - for example, actuating a claw or lightweight arm. Typically servos have limited range of rotation (180° is common). The output has splines, which are the rigid teeth that are on top of the servo.
Les servomoteurs sont couramment utilisés dans les voitures RC (pour la direction) et les avions RC (pour déplacer les ailerons). Dans le cadre de la compétition FTC, les servomoteurs sont généralement utilisés pour les griffes, les pinces et les bras.
A common servo, the goBILDA Dual Mode Servo¶
Note
Historically, servos were designed for fine-tuned and accurate movement in low-load applications, not high-load or fast rotation applications. However, modern high-performance servos (often designed and marketed specifically towards FTC teams) have pushed the limits of how powerful a servo can be, resulting in many teams using one or more high-power servo(s) to power mechanisms that do not need the power of a full motor, such as horizontal extensions and active intakes.
Il existe de nombreux servomoteurs provenant de différents fabricants, qui varient considérablement en termes de prix, de performance et de rapport qualité-prix. Heureusement, pratiquement tous les servomoteurs utilisent le connecteur standard à 3 fils et acceptent le même type de signal de commande (signal PWM à 50 Hz). Chaque REV Expansion Hub offre 6 ports pour servomoteurs, ce qui permet de connecter un servomoteur de n’importe quel fabricant. De plus, il existe une taille standard pour les servomoteurs utilisés dans la compétition FTC, ce qui permet de changer les supports entre différents fabricants.
Commonly used servos used in FTC are the goBILDA Dual Mode Servos and REV Smart Robot Servo, but you should check out other servos as well. Picking the right servo for your application is a question that’s almost impossible to give a blanket answer for. To learn more, please read the Choix d’un servo section.
The most prevalent problem with servos is durability. Internal servo gears in cheaper servos strip easily when subjected to shock loads. Servos are also often poor at handling lateral loads or bending of the shaft. To avoid having to frequently replace servos, choose ones with steel gears and use ServoBlocks or your kit’s equivalent to prolong longevity.